JP5848661B2 - Control device for throttle valve drive device - Google Patents

Description

  The present invention relates to a control device for a throttle valve drive device that drives a throttle valve provided in an intake passage of an internal combustion engine, and more particularly to a control device having a failure determination function of the throttle valve drive device.

  In Patent Document 1, an electromagnetic clutch is provided between the throttle valve and the motor. When the electromagnetic clutch is in the on state, the throttle valve is driven by the motor, while when the electromagnetic clutch is in the off state, the accelerator is A throttle valve driving device configured to mechanically drive a throttle valve according to an operation amount of a pedal is shown. Further, Patent Document 1 shows that when a failure of the throttle valve driving device is detected, a fail-safe operation for turning off the electromagnetic clutch is performed. As a failure detection method, a method is described in which a failure is determined when a state in which the difference between the command opening of the throttle valve and the detected opening is a predetermined deviation or more continues for a predetermined time or longer.

JP-A-4-350332

  As shown in Patent Document 1, it is necessary to confirm that the state in which the opening degree deviation is equal to or greater than the predetermined deviation has continued for a predetermined time in order to determine the determination that the throttle valve driving device is in failure. Usually it takes several hundred milliseconds. Therefore, there is a possibility that rapid acceleration unintended by the driver may be performed until the predetermined time elapses.

  The present invention has been made paying attention to this point, and a throttle valve that can reliably prevent unintended sudden acceleration by performing an appropriate fail-safe operation when a possibility of failure is detected. An object of the present invention is to provide a control device for a driving device.

In order to achieve the above object, according to the first aspect of the present invention, power is supplied from the power supply device (11), and the drive for driving the throttle valve (3) provided in the intake passage (2) of the internal combustion engine (1). In a control device for a throttle valve drive device comprising means (8, 9, 23), an opening degree control means for supplying a control signal (SCTL) to the drive means and controlling the opening degree of the throttle valve (3); Failure detection means for detecting a failure of the throttle valve drive device, and the drive from the power supply device (11) within a predetermined time (TFFIX) from the failure detection time point (t1) when the failure of the throttle valve drive device is detected. while maintaining the power supply to the means (8,9,23), wherein the output of the control signal (SCTL) from opening control means stops, the fault detection time (t1) the predetermined time (TFFIX) In elapsed time and a fail-safe processing means for stopping power supply from said power supply device (11) when said failure is maintained state detected to the drive means, the fail-safe processing means, When the throttle valve driving device returns to the normal state before the predetermined time (TFFIX) has elapsed from the failure detection time (t1), the output of the control signal (SCTL) from the opening control means is immediately performed. to start and said Rukoto.

According to the first aspect of the present invention , the opening degree control means controls the power supply from the power supply apparatus to the drive means within a predetermined time from the failure detection time when the failure of the throttle valve drive apparatus is detected. When the output of the signal is stopped and the state in which the failure is detected is maintained at the time when a predetermined time has elapsed from the time of failure detection, the power supply from the power supply device to the driving means is stopped. Since the output of the control signal is stopped as soon as a failure is detected, the throttle valve is not driven by the drive means, and unintended sudden acceleration can be reliably prevented. Further, when the failure detection state is maintained for a predetermined time, the power supply is stopped, so that the malfunction of the throttle valve can be prevented more reliably. Further, when the throttle valve driving device returns to the normal state before the predetermined time has elapsed from the time point of failure detection, the output of the control signal is immediately started. If the power supply is stopped, it is difficult to start normal control quickly even if it returns to the normal state.However, if the control signal output is only stopped while maintaining the power supply, the control signal output is disabled. By resuming, normal control can be started immediately, and quick return to normal control becomes possible.

It is a figure which shows the throttle valve drive device concerning one Embodiment of this invention, and its control apparatus. It is a block diagram which shows the one part structure of FIG. 1 in detail. It is a flowchart of the process which performs drive control of a throttle valve. It is a time chart for demonstrating the process of FIG.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a throttle valve driving device and its control device according to an embodiment of the present invention. A throttle valve 3 is provided in an intake passage 2 of an internal combustion engine (hereinafter referred to as “engine”) 1. The throttle valve 3 can be driven by a motor 6 via a gear mechanism 9. A return spring (not shown) that urges the throttle valve 3 in the valve closing direction and an elastic member (not shown) that urges the throttle valve 3 in the valve opening direction are attached to the throttle valve 3. Yes. Therefore, when the driving force by the motor 6 is not applied to the throttle valve 3, the opening TH of the throttle valve 3 is a default opening THDEF (for example, 5 degrees) in which the urging force of the return spring and the urging force of the elastic member are balanced. ).

  The motor 6 is connected to an electronic control unit (hereinafter referred to as “ECU”) 7, and its operation is controlled by the ECU 7. The throttle valve 3 is provided with a first throttle valve opening sensor 8a that detects the throttle valve opening TH, and a second throttle valve opening sensor 8b that similarly detects the throttle valve opening TH. The detection signal of the sensor is supplied to the ECU 7. The reason why two throttle valve opening sensors are provided is to improve reliability. The openings detected by the first and second throttle valve opening sensors 8a and 8b are hereinafter referred to as “first detection throttle valve opening TH1” and “second detection throttle valve opening TH2,” respectively.

  The ECU 7 is connected to an accelerator sensor 10 for detecting an accelerator pedal depression amount AP (hereinafter referred to as “accelerator pedal operation amount AP”) for detecting a request output of a driver of a vehicle on which the engine 1 is mounted. The detection signal is supplied to the ECU 7.

  FIG. 2 is a diagram more specifically showing the configuration of the ECU 7 and its peripheral circuits. The ECU 7 is a central processing unit (CPU) 21 that executes various arithmetic processes, an output circuit 23, a sensor power output terminal 24, and a power source. A circuit 25 is provided. First and second throttle valve opening sensors 8a and 8b and an accelerator sensor 9 are connected to the CPU 21 via an input circuit (not shown), and the CPU 21 detects detection converted into a digital value. The values, that is, the first detection throttle valve opening TH1, the second detection throttle valve opening TH2, and the accelerator pedal operation amount A are input.

  The output circuit 23 is connected to the battery 11 via the relay 12, and power is supplied from the battery 11 via the relay 12. One end of the exciting coil of the relay 12 is connected to the battery 11, and the other end is connected to the CPU 21. The relay 12 is on / off controlled by the CPU 21. FIG. 2 shows a state where the relay 12 is on.

  Driving power for the throttle valve 3 (hereinafter simply referred to as “driving power”), in other words, power for driving the motor 6 is supplied from the battery 11 via the relay 12 and the output circuit 23. On the other hand, the power supply voltage VS stabilized by the power supply circuit 25 is used as the power supply of the ECU 7 itself, and the power supply voltage VS is supplied to the sensor power supply output terminal 24. In FIG. 2, the output of the battery 11 is connected to the power supply circuit 25, but is actually connected via a switch circuit or the like.

  In the present embodiment, during normal control, the drive power is supplied by turning on the relay 12, while during the second fail-safe operation described later, the supply of drive power is stopped by turning off the relay 12 ( The drive power is cut off.

  The CPU 21 determines the target opening THR of the throttle valve 3 according to the accelerator pedal operation amount AP, and the detected throttle valve opening THX (either one of TH1 or TH2 is selected) matches the target opening THR. Thus, the control signal SCTL is determined and supplied to the output circuit 23. The output circuit 23 supplies a drive signal corresponding to the control signal SCTL to the motor 6.

  The CPU 21 further controls the throttle valve driving device (throttle valve opening sensors 8a and 8b, motor 6, gear mechanism 9, output circuit) based on the first and second detected throttle valve openings TH1 and TH2 and the target opening THR. The failure detection of 23) is performed, and fail-safe operation control according to the detection result is performed.

FIG. 3 is a flowchart of a throttle valve drive control process executed by the CPU 21 every predetermined time.
In step S11, it is determined whether or not the failure determination flag FFAIL is “1”. The failure determination flag FFAIL is a flag that is set to “1” when the failure determination is confirmed (see step S23), and is set to “0” when the failure determination is not confirmed. Therefore, initially, the answer to step S11 is negative (NO), and the process proceeds to step S12, where the first and second detected throttle valve opening TH1 input from the first and second throttle valve opening sensors 8a and 8b. , TH2 are read.

  In step S13, failure detection of the throttle valve drive device is performed based on the first and second detected throttle valve openings TH1 and TH2. As a failure detection method, 1) it is detected that the opening difference DTH (= | TH1-TH2 |) between the first detection throttle valve opening TH1 and the second detection throttle valve opening TH2 is equal to or greater than the correlation failure determination threshold. 2) Detect that first detection throttle valve opening TH1 and / or second detection throttle valve opening TH2 is equal to or less than a ground fault threshold value 3) First detection throttle valve opening TH1 or second detection A method is applied in which it is detected that the difference (control deviation) between the throttle valve opening TH2 and the target opening THR is equal to or greater than a deviation determination threshold. In the present embodiment, the failure detection in step S13 is a temporary failure detection, and the time when the detection waiting time TFDET has elapsed from the temporary failure detection time is the failure detection time.

  When a failure (provisional failure) is detected in step S13, the temporary detection flag FFDET is set to “1”. The temporary detection flag FFDET is “0” in the initial state, and is held at “1” while a failure is detected, and is returned to “0” when the normal state is restored.

  In step S14, it is determined whether or not the temporary detection flag FFDET is “1”. If the answer is negative (NO), the temporary failure flag FFTMP is set to “0” (step S16). Take control. That is, the drive power is supplied and the control signal SCTL is output (steps S17 and S18). The temporary failure flag FFTMP is a flag set to “1” in step S19 described later. In normal control, the control signal SCTL is set so that the detected throttle valve opening THX (TH1 or TH2) matches the target opening THR.

  If the answer to step S14 is affirmative (YES), it is determined whether or not a detection waiting time TFDET (for example, 10 msec) has elapsed since the provisional detection flag FFDET was set to “1” (step S15). While the answer to step S15 is negative (NO), the process proceeds to step S16 and normal control is continued.

  If the answer to step S15 is affirmative (YES), the process proceeds to step S19, and the temporary failure flag FFTMP is set to “1”. In the subsequent step S20, it is determined whether or not a fixed waiting time TFFIX (for example, 200 msec) has elapsed since the provisional failure flag FFTMP was set to “1”. Initially, this answer is negative (NO), and the first fail-safe operation for stopping the output of the control signal SCTL is performed while maintaining the supply of the drive power (steps S21 and S22). When the output of the control signal SCTL is stopped, the driving force of the motor 6 is not applied to the throttle valve 3, so that the opening degree of the throttle valve 3 changes to the default opening degree THDEF.

  If the temporary detection flag FFDET is returned to “0” before the answer to step S20 becomes affirmative (YES), the answer to step S14 becomes negative (NO) and the normal control is restored. Since the supply of drive power is maintained, a quick return is possible.

  If the answer to step S20 is affirmative (YES) in a state where the temporary failure flag FFTMP is set to “1”, it is determined that the throttle valve driving device has failed, and the failure determination flag FFAIL is set to “1”. (Step S23), the second fail-safe operation for shutting down the drive power supply and stopping the output of the control signal SCTL is performed (Steps S24 and S25). If the failure determination flag FFAIL is set to “1”, the answer to step S11 is affirmative (YES) and the process immediately proceeds from step S11 to step S24 is repeated.

  FIG. 4 is a time chart for explaining the processing of FIG. 3. FIG. 4A shows the actual opening THA (solid line) of the throttle valve 3 and the first detected throttle valve opening TH1 (thick broken line). The second detected throttle valve opening TH2 (thin broken line) is also shown. FIG. 4 shows an example in which the opening degree difference DTH described above is equal to or greater than the relative failure determination threshold value.

  A failure of the first throttle valve opening sensor 8a occurs slightly before time t0, the first detected throttle valve opening TH1 starts to decrease, and the opening difference DTH becomes equal to or greater than the relative failure detection threshold at time t0. The provisional detection flag FFDET is set to “1” ((b) in the figure). At this time, the second throttle valve opening sensor 8b is normal, and the second detected throttle valve opening TH2 is substantially equal to the actual opening THA.

  The normal control is continued until the detection waiting time TFDET elapses from the time t0. At the time t1 when the detection waiting time TFDET elapses, the temporary failure flag FFTMP is set to “1” ((c) in the figure), and the drive A first fail-safe operation for stopping the output of the control signal SCTL while maintaining the supply of power is started ((e) in the figure). As a result, the actual opening THA changes toward the default opening THDEF and is maintained at the default opening THDEF.

  After that, at time t2 when the fixed waiting time TFFIX has elapsed from time t1, it is determined that there is a failure, the failure determination flag FFAIL is set to “1” ((d) in the figure), and the control signal SCTL is output. And a second fail-safe operation for stopping the drive power supply is started ((e) in the figure). Therefore, the actual opening THA is reliably maintained at the default opening THDEF.

  Note that the alternate long and short dash line in FIG. 4A shows a change example of the actual opening THA when the normal control is executed until the time t2 when the failure determination is fixed, and the period until the fixed waiting time TFFIX elapses. , The actual opening THA greatly increases, and acceleration that is not intended by the driver may be performed. On the other hand, according to the process of FIG. 3, the actual opening THA is controlled to be equal to or less than the maximum opening THMAX, and sudden acceleration unintended by the driver can be reliably avoided.

  As described above, in the present embodiment, the time t1 at which the temporary failure flag FFTMP is set to “1” corresponds to the “failure detection time point” described in claim 1, and until the fixed waiting time TFFIX elapses from the time t1. In the period, the output of the control signal SCTL is stopped while maintaining the supply of the drive power (first fail-safe operation), and the temporary detection flag FFDET (provisional failure flag) at the time t2 when the fixed waiting time TFFIX has elapsed from the time t1. When FFTMP) is “1”, the output of the control signal SCTL is stopped and the supply of drive power is stopped (second fail-safe operation). Since the output of the control signal SCTL is immediately stopped at the time of failure detection (t1), the actual opening THA of the throttle valve 3 quickly shifts to the default opening THDEF, and unintentional rapid acceleration can be reliably prevented. Further, when the failure detection state (the state where the temporary failure flag FFTMP is “1”) is maintained for the fixed waiting time TFFIX, the supply of the driving power is stopped, so that the malfunction of the throttle valve 3 is more reliably performed. Can be prevented.

  Further, when the throttle valve driving device returns to the normal state before the fixed waiting time TFFIX elapses from time t1, that is, when the temporary failure flag FFTMP is returned from “1” to “0”, the control signal SCTL Output is started immediately (FIGS. 3, S14 and S18). When the supply of drive power is stopped, it is difficult to quickly start normal control even if the normal state is restored. However, when the output of the control signal SCTL is stopped, the output of the control signal SCTL is resumed. Thus, normal control can be started immediately, and quick return to normal control becomes possible.

  In the present embodiment, the battery 11 corresponds to a power supply device, the throttle valve opening sensors 8a and 8b, the motor 6, the gear mechanism 9, and the output circuit 23 correspond to a throttle valve driving device, and the motor 6, the gear mechanism 9, The output circuit 23 corresponds to drive means, the relay 12 corresponds to part of fail-safe processing means, and the CPU 21 constitutes part of opening control means, failure detection means, and fail-safe processing means. More specifically, step S13 in FIG. 3 corresponds to the failure detection means, and steps S14 to S16 and S19 to S25 correspond to the fail safe processing means.

  The present invention is not limited to the embodiment described above, and various modifications can be made. For example, in the above-described embodiment, an example in which two throttle valve opening sensors are provided has been described. However, the present invention is not limited to this, and the present invention is a throttle in which only one throttle valve opening sensor is provided. The present invention can also be applied to a control device for a valve driving device.

Further, the power supply device is not limited to a battery, and may be only a generator driven by an engine or a combination of a generator and a battery.
The present invention can also be applied to control of a throttle valve drive device provided in a marine vessel propulsion engine such as an outboard motor having a vertical crankshaft.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Intake passage 3 Throttle valve 6 Motor (throttle valve drive device)
8a, 8b Throttle valve opening sensor (throttle valve drive device)
11 Battery (Power supply)
12 Relay (Fail-safe processing means)
21 CPU (opening control means, failure detection means, fail-safe processing means)
23 Output circuit (throttle valve drive)

Claims (1)

In a control device for a throttle valve drive device, which is supplied with power from a power supply device and includes a drive means for driving a throttle valve provided in an intake passage of an internal combustion engine.
An opening degree control means for supplying a control signal to the driving means and controlling an opening degree of the throttle valve;
Failure detection means for detecting a failure of the throttle valve drive device;
The output of the control signal from the opening degree control means is stopped while maintaining the power supply from the power supply apparatus to the drive means within a predetermined time from the failure detection time when the failure of the throttle valve drive apparatus is detected. And
Fail-safe processing means for stopping power supply from the power supply device to the driving means when the state in which the failure is detected is maintained at the time when the predetermined time has elapsed from the failure detection time point ,
The fail-safe processing unit immediately starts outputting the control signal from the opening degree control unit when the throttle valve driving device returns to a normal state before the predetermined time has elapsed from the time when the failure was detected. A control device for a throttle valve drive device.

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