JPH05202772A - Engine throttle control device - Google Patents

Abstract

PURPOSE:To improve the safety or the like by diagnosing the engagement at a plurality of electromagnetic clutches immediately after the ignition switch is turned on, and prohibiting the start of the engine until this diagnosis is completed, thereby surely achieving the countermeasures for the engagement. CONSTITUTION:The first clutch which is engaged under the non-excited condition, and released under the excited condition is interposed in the engagement system between an acceleration pedal and a throttle valve. The second clutch which is released under the non-excited condition, and engaged under the non- excited condition is interposed in the engagement system between a motor and the throttle valve. In this device, diagnosis on the engagement is achieved by means of a clutch engagement diagnosing device in the engaged or released condition immediately after the ignition switch is turned on. Then, the starting of the engine is prohibited by a start-inhibiting means until the diagnosis is completed. This arrangement allows the countermeasures of the representative electromagnetic clutches to be surely achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine throttle control device, and more particularly to a device provided with an electronic throttle actuator.

[0002]

2. Description of the Related Art As a conventional electronic throttle actuator, for example, one disclosed in Japanese Patent Application Laid-Open No. 2-30933 can be cited. This is the first electromagnetic clutch of the normally closed type that is in the connected state when de-energized and the second electromagnetic clutch of the normally open type that is in the released state when de-energized.
And an electromagnetic clutch, wherein the first electromagnetic clutch is provided in the connection system between the accelerator pedal and the throttle valve, and the second electromagnetic clutch is provided in the connection system between the motor and the throttle valve. It is a thing.

According to this, in the normal state, the first and second
By energizing the electromagnetic clutch, the motor opens and closes the throttle valve, and when there is an abnormality, the first and second electromagnetic clutches are de-energized and the accelerator pedal opens and closes the throttle valve to allow traveling. Becomes

[0004]

However, the above-mentioned effect is first brought about by simultaneously energizing or simultaneously deenergizing two electromagnetic clutches having different characteristics. If this state is not satisfied, there is a problem that the driver's operation command may not be transmitted to the throttle valve or an unpleasant reaction force may be exerted on the accelerator pedal. That is,
When only the first electromagnetic clutch is energized, both electromagnetic clutches are disengaged, and neither the operation command from the accelerator pedal nor the operation command from the motor is transmitted to the throttle valve. In addition, when only the second electromagnetic clutch is energized, both electromagnetic clutches are in a connected state, and the motor, the throttle valve, and the accelerator pedal operate in conjunction with each other at the same time. There is a possibility that an unpleasant reaction force is exerted on the accelerator pedal or the control system may diverge depending on the throttle control method.

Therefore, as a countermeasure against such a problem, it is considered that two electromagnetic clutches are electrically connected in series and driven by a single drive circuit. However, when sticking occurs in the connected state or the released state due to a mechanical failure of the electromagnetic clutch, unless such sticking is surely detected and the corresponding processing is not surely performed, the above-mentioned problems still occur. Can occur.

In view of such conventional problems, the present invention has an object to take measures against sticking in an engaged state or a released state due to mechanical failure of an electromagnetic clutch.

[0007]

Therefore, according to the present invention, as shown in FIG. 1, a first electromagnetic clutch that is in a connected state when not energized and is in an open state when energized, and in an open state when not energized,
It has a second electromagnetic clutch that is in a connected state when energized,
A throttle control device for an engine, wherein the first electromagnetic clutch is provided in a connection system between an accelerator pedal and a throttle valve, and the second electromagnetic clutch is provided in a connection system between a motor and a throttle valve. Immediately after the switch is turned on, a clutch sticking diagnosis means for diagnosing whether or not the first and second electromagnetic clutches are stuck in the engaged and disengaged states, and a start prohibiting means for prohibiting engine start until the diagnosis is completed are provided. It is what

[0008]

In the above construction, even if the electromagnetic clutch is stuck in the connected state or the released state due to a mechanical failure, it is diagnosed immediately after the ignition switch is turned on and the engine start is prohibited until the diagnosis is completed. , It is perfect as a safety measure.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The present embodiment uses an electronic throttle actuator of the type described above to perform automatic constant vehicle speed control (ASCD control) when the accelerator is not stepped on, and driving force characteristic seasoning control when the accelerator is stepped (accelerator-by-wire control). This is a system that ensures the safety by detecting abnormalities when performing both.

FIG. 2 shows the structure of the electronic throttle actuator. A throttle valve return spring 3 for urging the throttle valve 1 in a closing direction is applied to a valve shaft 2 of the throttle valve 1. An accelerator drum 6 connected to an accelerator pedal 4 (see FIG. 3) via a wire 5 is rotatably supported at one end of a valve shaft 2 of the throttle valve 1. The accelerator drum 6 is provided with an accelerator drum return spring 7 which biases the accelerator drum 6 in the closing direction.

A first electromagnetic clutch 8 is interposed between the accelerator drum 6 and the valve shaft 2. The first electromagnetic clutch 8 includes a clutch body 8a attached to the accelerator drum 6, and a clutch plate 8b that rotates integrally with the valve shaft 2 and is slidable in the axial direction. In this first electromagnetic clutch 8, the clutch plate 8b moves in the direction of connection with the clutch body 8a with the spring 8c.
When the coil 8d is not energized, the coil 8d is in a connected state and is energized in an open state (normally closed).

At the other end of the valve shaft 2 of the throttle valve 1, a motor drum 11 driven by a DC motor 9 via a reduction gear 10 is rotatably supported. A second electromagnetic clutch 12 is provided between the motor drum 11 and the valve shaft 2.

The second electromagnetic clutch 12 is the motor drum 11
The clutch body 12a attached to the clutch plate 12 that is rotatable integrally with the valve shaft 2 and is slidable in the axial direction.
b. In this second electromagnetic clutch 12, the clutch plate 12b is constantly urged by the spring 12c in the disengagement direction with the clutch body 12a, and is in the disengaged state when the coil 12d is not energized and in the connected state when energized (normally open). ).

A potentiometer type accelerator sensor 21 for measuring the rotation angle of the accelerator drum 6 is arranged at a predetermined position. Regarding the accelerator sensor, the accelerator sensor 22 (see FIG. 3) that measures the depression angle of the accelerator pedal 4 is used.
(See) is arranged as a dual system. Further, a potentiometer type throttle sensor 23 for measuring the rotation angle of the throttle valve 1 is arranged at a predetermined position.

FIG. 3 shows the system configuration. The above electronic throttle actuator (DC motor 9, first and second electromagnetic clutches 8 and 12) is driven by a throttle control module (TCM) 30, and the throttle control module 30 includes the following sensors 21 to 28. -A signal is being input from the switch.

Reference numerals 21 and 22 denote accelerator sensors (double system), which detect the accelerator opening Acc by the output voltage of the potentiometer. A throttle sensor 23 detects the throttle opening Tvo by the output voltage of the potentiometer. A vehicle speed sensor 24 outputs a pulse signal having a frequency proportional to the vehicle speed Vsp by an electromagnetic pickup or the like provided on the transmission output shaft.

Reference numeral 25 is an ASCD set switch for instructing the start of automatic constant vehicle speed control (ASCD control). 26 is an ASC instructing cancellation of automatic constant vehicle speed control (ASCD control)
It is a cancel switch for D. 27 is accelerator pedal 4
This is an accelerator limit switch that is turned off only when is not operated.

Reference numeral 28 is a brake limit switch which is turned on only when the brake pedal (not shown) is not operated. The throttle control module (TCM) 30 is composed of the following blocks 31 to 36. Reference numeral 31 is a one-chip microcomputer, which has a built-in CPU, ROM, RAM, A / D converter, various timers, digital port, and the like.

The microcomputer 31 performs a self-check by turning on the ignition switch 41, and outputs a self-check signal SC from the digital port P via an output circuit 36, which will be described later, to the engine control module (E).
CM) 42, and the warning / self-check lamp 43 is turned on. After the self-check,
When the system is normal, the self-check signal SC is released, and the CLUTCH signal for instructing the energization of the first and second electromagnetic clutches 8 and 12 is output.
Calculate the target throttle opening based on the switch signal,
DIR for instructing the forward and reverse rotation directions of the DC motor 9 so that the actual throttle opening matches the target throttle opening.
It outputs a signal and a DUTY signal indicating the drive current of the DC motor 9.

When the system is out of order, the motor control signals (DIR, DUTY) and the clutch control signal (CLU).
TCH) is initialized, that is, an output for instructing cutoff of the motor drive current and the clutch drive current is performed, and the DC motor 9
The throttle control by the accelerator pedal 4 is changed to the direct throttle drive. At this time, the warning / self-check lamp 43 is turned on by a signal from the digital port P via an output circuit 36 described later.

Further, when the system is abnormal such as the clutch being stuck, the motor control signals (DIR, DUTY) and the clutch control signal (CLUTCH) are initialized, that is, the output is turned off to maintain the mechanical backup state and at the same time, the digital port. A signal from P turns on a warning / self-check lamp 43 via an output circuit 36 described later. 32
Is a DC motor drive circuit. Based on a motor control signal (DIR, DUTY) from the microcomputer 31, only one set of power transistors diagonally located in the DC motor drive bridge circuit is turned on. Then, the motor drive current and the current direction are controlled.

33 is a self-holding relay circuit,
Only when the set switch 25 for
Thereafter, until the cancel switch 26 is pressed or the brake pedal is depressed to turn off the brake limit switch 28 or turn off the ignition switch 41,
Hold on state. A circuit having such a function is publicly known, and a specific circuit configuration follows the conventional example.

Reference numeral 34 is an electromagnetic clutch drive circuit which turns on / off the power transistor based on a clutch control signal (CLUTCH) from the microcomputer 31. The power transistor, the first electromagnetic clutch 8 and the second electromagnetic clutch 12 are connected in series. That is, the first and second electromagnetic clutches 8 and 12 are electrically connected in series and driven by a single drive circuit 34.

Reference numeral 35 is a control circuit power supply, which supplies power (5 V) for the control circuit to the microcomputer 31 and other control circuits from the battery voltage supplied from the ignition switch 41. A digital signal output circuit 36 converts a signal from the digital port P of the microcomputer 31 into an output signal to the outside, sends the output signal to the engine control module (ECM) 42, and also drives a warning / self-check lamp 43.

The engine control module 42 performs various controls of the engine including fuel injection control and ignition control, and when the self-check signal SC is input from the throttle control module 30, prohibits fuel injection control and controls ignition. The engine start is prohibited by either or both of the prohibitions. It should be noted that the self-check signal SC indicates that the throttle control module 30 is performing the self-check immediately after the ignition switch 41 is turned on during the self-check period.
Output from 30 to the engine control module 42.

The warning and self-check lamp 43 is
It is controlled by the throttle control module 30 and lights up during self-check and when an abnormality occurs. 4 and 5 show control operations performed by the microcomputer 31 of the throttle control module (TCM) 30, and FIG. 4 (P1 to P15)
Is a self-check processing routine as a clutch sticking diagnosis means, which is executed when the ignition switch 41 is turned on and power for the control circuit is supplied. Figure 5 (P16-P34)
Is a main routine for normal control. After the self-check processing routine ends, a fixed cycle (for example, 10 msec)
It is executed every time.

When the ignition switch 41 is turned on and the power for the control circuit is supplied, the control of the microcomputer 31 is started from P1. At P1, the system is initialized, and the self-check signal S
Output C. At P2, in order to perform a self-check in the connected state on the first electromagnetic clutch 8 side (the released state on the second electromagnetic clutch 12 side), the clutch control signal (CLUTC
An off signal is output as H) to stop energizing the first and second electromagnetic clutches 8 and 12.

At P3, a motor control signal (DIR, DUTY) for driving the DC motor 9 is output, and the next P
In 4, the accelerator opening Acc and the throttle opening Tvo are monitored. At this time, in order to avoid erroneous diagnosis due to the influence of the accelerator operation by the driver, processing such as opening and closing at a fast cycle is performed. At P5, the result of monitoring the throttle opening Tvo is compared with the motor driving state, that is, the actual throttle opening Tvo is compared with the opening obtained from the energization current to the DC motor 9, and their changes are matched. if,
When it is determined that the second electromagnetic clutch 12 is fixed in the connected state (No. 2, close fixing), the process proceeds to P11.

If they do not match at P5, the process proceeds to the next self-check (P6). At P6, an ON signal is output as a clutch control signal (CLUTCH) in order to perform a self-check in a connected state on the second electromagnetic clutch 12 side (a released state on the first electromagnetic clutch 8 side), and the first and the second electromagnetic clutches are output. Energize the second electromagnetic clutches 8 and 12. In P7 and P8,
Similarly to P3 and P4, the DC motor 9 is driven to monitor the accelerator opening Acc and the throttle opening Tvo.

In P9, when Tvo = 0 as a result of monitoring, it is determined that the second electromagnetic clutch 12 is stuck in the open state (No. 2 open sticking), and the control in P12 to P14 when the system is abnormal. I do. If Tvo ≠ 0 in P9, the process proceeds to the next P10. At P10, the results of monitoring the throttle opening Tvo and the accelerator opening Acc are compared to determine whether they match. If they match, the first electromagnetic clutch 8
Judgment is fixed in the connected state (No. 1 close fixed),
Controls when the system is abnormal in P12 to P14.

If they do not match at P10, it is judged that the system is normal, and the routine proceeds to P15. At P15, the output of the self-check signal SC is released, and thereafter, at P16, the routine proceeds to the main routine of FIG. 5 for normal control. The processing when the first and second electromagnetic clutches 8 and 12 are abnormal is performed as follows. Sticking of the second electromagnetic clutch 12 in the connected state (No. 2
In the case of (closed fixation), the process proceeds to P11, but at this time, since the motor control of the throttle is possible, the warning / self-check lamp 43 is used to alert the driver of the abnormality at P11.
Is turned on, and then the program proceeds to P15 to cancel the output of the self-check signal SC, and thereafter, from P16, the routine proceeds to the main routine of FIG. 5 for normal control.

When the second electromagnetic clutch 12 is fixed in the open state (No. 2 open fixed) or the first electromagnetic clutch 8 is fixed in the connected state (No. 1 closed fixed), the throttle motor control is performed. Since it cannot be done, the accelerator pedal is directly connected to the throttle valve and a mechanical backup state is entered.
Therefore, first in P12, the warning / self-check lamp 43 is turned on to warn the driver of the abnormality, then in P13, the output of the self-check signal SC is released, and then in P14, the motor control signals (DIR, DUTY) are released. Also, the clutch control signal (CLUTCH) is initialized to zero, that is, the output is turned off. Then, returning to P12, the loop of P12 to P14 holds the mechanical backup state when the system is abnormal.

Next, the main routine of FIG. 5 for normal control will be described. At P17, the system is diagnosed based on the sensor / switch signals and the like to confirm whether or not there is a failure. In P18, if there is a failure based on the result of P17, the procedure proceeds to P19, and if there is no failure, the procedure proceeds to P21.

At the time of failure, at P19, the motor control signal (DI
R, DUTY) and clutch control signal (CLUTCH)
Is initialized to zero. Then, at P20, the warning / self-check lamp 43 is turned on to warn the driver of the failure. Then, the process proceeds to P34 described later. This allows
The throttle control by the DC motor 9 is shifted to the throttle direct drive by the accelerator pedal 4.

During normal operation, the accelerator opening A is set at P21 to P23.
cc, throttle opening Tvo, and vehicle speed Vsp are read from each sensor and calculated. Then, proceed to P24. At P24, it is determined from the value of the flag switch Fmode whether the ASCD control or the accelerator-by-wire control has been performed until now. If Fmode = 1 (during accelerator-by-wire control), proceed to P25, and if Fmode = 0 (ASCD control), proceed to P28.

During accelerator-by-wire control, at P25, A
It is determined whether the set switch 25 for instructing the start of the SCD control is turned on. If it is turned on, the process proceeds to P26 to start the ASCD control, and otherwise proceeds to P32 to continue the accelerator-by-wire control. When shifting to the ASCD control, in P26, the flag switch Fmode = 0 is set,
At the next P27, the current vehicle speed Vsp ₀ is stored as the target vehicle speed Vspr. Then, proceed to P30.

At P30, calculation of ASCD control is performed. You
That is, using a known control method such as PID control,
Vehicle speed Vsp₀Between the target vehicle speed and the target vehicle speed Vspr (Vspr −
Vsp ₀), The target throttle opening Tvor is calculated. So
Then, proceed to P33. In P33, known controls such as PID control
Current throttle opening Tvo₀And goals
Throttle opening deviation from the rottle opening Tvor (Tvor-
Tvo₀), Which indicates the direction of motor rotation based on
Signal and DUTY signal that indicates motor drive current
To do. Then, the process proceeds to P34.

At P34, the above-mentioned DIR and DUTY are written into a predetermined I / O register of the microcomputer 31, and these are output. During P28 during the ASCD control, it is determined whether or not the cancel switch 26 for instructing the cancellation of the ASCD control is turned on. If it is turned on, the process proceeds to P31 to start the accelerator-by-wire control, and if not, the process proceeds to P29.

At P29, it is determined whether or not the brake pedal is depressed by turning on / off the brake limit switch 28. If the brake pedal is stepped on, proceed to P31 to start accelerator-by-wire control.
Proceed to P30 to continue SCD control. When shifting to accelerator-by-wire control, the flag switch Fmode =
Set 1. Then, the process goes to P32.

At P32, accelerator-by-wire control calculation is performed. That is, the target throttle opening degree Tvor is calculated from the actual accelerator opening degree Acc based on the accelerator opening-throttle opening correspondence map which is predetermined in consideration of the characteristics of the engine and the vehicle. Then, the process goes to P33 and P34. Figure 6
Indicates the control contents of the engine control module (ECM) 42, which includes a function as a start prohibiting means.

It is executed when the ignition switch 41 is turned on and power is supplied to the engine control module 42. First, on P101, the engine control module
42 initial settings. Next, at P102, the self-check signal SC from the throttle control module 30 is checked, and if this is input, at P103, either or both of the fuel injection control prohibition and the ignition control prohibition are applied to the engine. Prohibit starting. Then, the loop of P102 and P103 is circulated until the self-check signal SC is released.

If the result of checking the self-check signal SC at P102 is canceled, the program proceeds to P104 to perform normal engine control. The operation and effect of this embodiment will be described. The failure of the electromagnetic clutch does not affect the system function when the locked state is controlled,
Moreover, failure detection is also impossible. In an electronic throttle control system such as the conventional example, when the vehicle is not in use, that is, when the electromagnetic clutch is normal when the ignition switch is off, the first electromagnetic clutch (accelerator pedal side) is engaged. , The second electromagnetic clutch (motor side) is opened. First in this state
If sticking occurs in the connected state of the electromagnetic clutch of the
There is a possibility that the throttle valve and the accelerator pedal may operate together, exert an unpleasant reaction force on the accelerator pedal, and the control system may diverge depending on the throttle control method. In order to prevent this,
A self-check is performed immediately after the ignition switch is turned on, and the engine is prohibited from starting until the end of the ignition switch.By doing so, it is possible to reliably detect the occurrence of sticking and perform fail-safe control, thus improving system safety. be able to.

[0043]

As described above, according to the present invention, immediately after the ignition switch is turned on, it is diagnosed whether or not the first and second electromagnetic clutches are stuck in the engaged and disengaged states, and the engine is maintained until the diagnosis is completed. By prohibiting the start of the above, it is possible to obtain an effect that it is possible to surely take measures against the sticking.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention.

FIG. 2 is a structural diagram of an electronic throttle actuator showing an embodiment of the present invention.

FIG. 3 is a system configuration diagram of the above embodiment

FIG. 4 is a flowchart of a self-check processing routine.

FIG. 5 is a flowchart of a main routine

FIG. 6 is a flowchart showing the control contents of the engine control module.

[Explanation of symbols] 1 throttle valve 2 valve shaft 4 accelerator pedal 5 wire 6 accelerator drum 8 first electromagnetic clutch 9 DC motor 11 motor drum 12 second electromagnetic clutch 30 throttle control module 31 one-chip microcomputer 32 DC motor drive circuit 34 Electromagnetic clutch drive circuit 36 Digital signal output circuit 41 Ignition switch 42 Engine control module 43 Warning and self-check lamp

Claims (1)

[Claims] 1. An accelerator pedal and a throttle having a first electromagnetic clutch that is engaged when not energized and that is disengaged when energized, and a second electromagnetic clutch that is disengaged when not energized and engaged when energized. Immediately after the ignition switch is turned on, in a throttle control device for an engine, in which the first electromagnetic clutch is provided in a connection system with a valve and the second electromagnetic clutch is provided in a connection system with a motor and a throttle valve. To the first and second
2. A throttle control device for an engine, comprising: clutch sticking diagnosis means for diagnosing whether or not the electromagnetic clutch is stuck in a connected state and a disengaged state, and a start prohibiting means for prohibiting starting of the engine until the diagnosis is completed.