JPH0344215B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for determining failure of an idle sensor that detects that an engine is in an idling operating state, and in particular to a device for controlling the idling operating state of an engine. The present invention relates to an idle sensor failure determination device suitable for use in an idle sensor failure display device or an idle sensor failure display device.

[Conventional technology]

Conventionally, some engine idle control devices detect engine speed, throttle valve opening, vehicle speed, etc., and supply control signals based on these detection signals to the motor to move the rod forward or backward. By moving the stop position of the throttle valve, feedback control of the engine speed (rotation speed feedback control) is performed under certain conditions during idling operation, while under other conditions during idling operation, A throttle valve that allows position feedback control of the throttle valve has been proposed.

Here, the above conditions refer to a case where at least the following items are satisfied, and refer to a condition in which the engine is relatively stable.

(1) A predetermined amount of time has elapsed after the idle switch was turned from off to on.

(2) The vehicle speed is extremely low (for example, 2.5 km/h or less), that is, the signal frequency from the vehicle speed sensor, which detects vehicle speed with a pulse signal having a frequency proportional to the vehicle speed, is below a predetermined value.

(3) The deviation of the actual engine speed (actual speed) from the target speed must be within a specified range.

(4) In vehicles equipped with a cooler, after the cooler relay etc. switches according to the cooler load,
The specified time has elapsed.

Further, the above conditions refer to conditions when the above conditions are not satisfied, the engine is relatively unstable, and rapid feedback control is desired.

By the way, conventional engine idle control devices are also capable of performing anticipatory control called dumppot control in order to prevent a shock when the throttle valve is suddenly closed.

In other words, in this dartpot control, if the engine continues to operate in a certain state (for example, a high load state) for a predetermined period of time or longer, the rod is moved to a certain position (throttle opening corresponding to this position) even if the throttle valve is not closed. The dart pot is moved forward according to expectations until it reaches a standby opening (which is larger than the normal fast idle opening).

As a result, the throttle valve stop position is set to a position greater than the normal idle opening position.

This kind of operation is called a dart pot standby anticipation operation. When the throttle valve suddenly closes while the dart pot is on standby, the throttle valve becomes fully closed. If the idle switch worked normally, it would turn on, but if the idle switch is As a trigger, the rod gradually retreats. As a result, the throttle valve gradually decreases from the dart pot standby opening to a desired opening (eg, fast idle opening).

Note that this kind of operation is called a dart pot tailing operation.

In this way, an overburden condition due to temporary fuel retention that may occur when the throttle valve is suddenly closed is avoided, thereby contributing to the prevention of a shock.

In addition, in order to realize fast idle control when the engine is cold, even when the accelerator pedal is pressed to start the engine (idle switch is off), the rod is projected when the coolant temperature is low, and then The rod is also moved backward as the cooling water temperature rises.

[Problem that the invention seeks to solve]

However, in conventional engine idle control devices, if the idle switch is malfunctioning (including a disconnection of the harness), the idle switch will not turn on, and a trigger signal will not be input. Shuttle pot tailing operations and operations that reduce the throttle opening as the cooling water temperature rises do not start.
As a result, a high engine rotational state is maintained, resulting in a problem of deterioration of driving controllability.

The present invention aims to solve such problems, and provides an idle sensor failure determination device that can reliably determine that the idle sensor is malfunctioning when the idle sensor malfunctions. The purpose is to

[Means for solving problems]

Therefore, the idle sensor failure determination device of the present invention includes a throttle valve provided in an intake passage of an engine, an idle sensor that detects the idle operating state of the engine according to opening and closing of the throttle valve, and a throttle valve provided in the intake passage of the engine. a throttle sensor for detecting an opening; a throttle valve opening change rate detecting means for detecting a rate of change in the throttle valve opening; the throttle opening detected by the throttle sensor is smaller than a predetermined opening; idle state estimating means for estimating that the engine is in an idling state when the throttle valve opening state change speed detected by the throttle valve opening state change speed detecting means is smaller than a predetermined speed; The present invention is characterized by comprising a failure determining means for determining that the idle sensor has failed when the idle sensor is not detected and the idle operating state is estimated by the idle state estimating means.

[Effect]

With such a configuration, even when the idle sensor fails and the engine idle operating state is not detected even though the engine is in the idle operating state, this failure determination means J can detect the idle switch, the throttle sensor, and the engine idle operating state. In response to the signal from the throttle valve opening change speed detecting means, the idle switch does not detect the idle operation state (although the idle switch remains off), but the throttle valve opening change speed reaches a predetermined value. If it is detected to be less than the value
It determines that the idle sensor is malfunctioning and outputs a signal to that effect.

〔Example〕

Hereinafter, an idle sensor failure determination device as an embodiment of the present invention will be explained with reference to the drawings.
Figures 1 to 14 show an engine idle control system having this device. Figure 1 is a flowchart showing the idle sensor failure determination procedure, Figure 2 is its overall configuration, and Figure 3 is its main part configuration. 4 to 8 are graphs for explaining the action, and FIGS. 9 to 14 are flowcharts for explaining the action, respectively.

As shown in FIG. 2, an internal combustion engine E such as a gasoline engine for use in an automobile according to this embodiment
(hereinafter simply referred to as "Engine E") is equipped with a turbocharger 3. The turbocharger 3 includes a turbine 4 interposed in the exhaust passage 2 of the engine E, and a compressor 5 interposed in the intake passage 1 of the engine E and rotationally driven by the turbine 4.

Note that a bypass passage that detours around the turbine installation portion of the exhaust passage 2 is connected to the exhaust passage 2,
A waste gate valve 6 is provided to open and close this bypass passage. This wastegate valve 6 is designed to be opened and closed by a two-diaphragm type pressure response device 7, but an electromagnetic switching valve 34 (this valve 34 has a return spring (not shown) for the valve body) Therefore, by selectively supplying atmospheric pressure and supercharging pressure to one pressure chamber of the pressure response device 7, the opening timing of the waste gate valve 6, etc. can be adjusted, and at least two types of supercharging pressure characteristics can be realized. It's becoming like that.

In addition, in the intake passage 1 of the engine E, in order from the upstream side (air cleaner side), an air flow sensor 16, a compressor 5 of the turbocharger 3,
An intercooler 8, electromagnetic fuel injection valves 9 and 10 (these valves 9 and 10 have different injection capacities), and a throttle valve 11 are provided in the exhaust passage 2 of the engine E on the upstream side (engine combustion chamber side) A turbine 4 of the turbocharger 3, a catalytic converter 31, and a muffler (not shown) are provided in this order.

As shown in Fig. 3, intake passage 1 of engine E
A shaft 11a of a throttle valve 11 disposed in the throttle valve 11 is connected to a throttle lever 1c outside the intake passage 1.

Further, when an accelerator pedal (not shown) is depressed, the end portion 11d of the throttle lever 11c
Throttle valve 1 via throttle lever 11c
A wire (not shown) is connected to the throttle valve 11 to rotate the throttle valve 11 in the clockwise direction (opening direction) in FIG. 1) is installed, so that when the tensile force of the wire is weakened, the throttle valve 11 closes.

By the way, an actuator 12 is provided that controls the opening degree of the throttle valve 11 during engine idling operation, and this actuator 12 is equipped with a DC motor (hereinafter simply referred to as "motor") 13 having a worm 14a on its rotating shaft. hand,
The worm 14a with the motor 13 meshes with an annular worm wheel 14b.

This worm wheel 14b has a female threaded portion 14.
A rod (stopper member) 15 having a male threaded portion 15a screwed into the female threaded portion 14d of the pipe shaft 14c passes through the worm wheel 14b and the pipe shaft 14c. installed.

The tip of the rod 15 comes into contact with the end 11d of the throttle lever 11c via an idle switch 25 as an idle sensor when the throttle valve 11 is in a fully closed state. That is, the rod 15 restricts the fully closed stop position of the throttle valve 11.

Here, the idle switch 25 is a switch that is turned on (closed) when the throttle valve 11 is at the fully closed stop position (during engine idling operation), and turned off (open) at other times.

Note that the rod 15 is formed with a long hole 15b, and a pin (not shown) on the actuator body side is guided into this long hole 15b, thereby preventing the rod 15 from rotating. It's getting messy.

As described above, since the tip of the rod 15 is in contact with the engine E when it is in the idle operating state, by rotating the motor 13 in a certain direction, the pipe shaft 14c is rotated via the worm gear, and the rod 15 is rotated. When the rod 1 is protruded (advanced) from the actuator 12, the throttle valve 11 is opened, the motor 13 is rotated in the opposite direction, and the rod 1 is moved forward.
5 into the actuator 12, the throttle valve 11 can be controlled to close by the action of the return spring.

That is, by driving the rod 15,
By changing the fully closed stop position of the throttle valve 11, the idle opening degree of the throttle valve 11 can be controlled.

Further, a throttle sensor 20 is provided to detect the opening degree of the throttle valve 11 (throttle opening degree), and a potentiometer or the like that generates a voltage proportional to the throttle opening degree is used as the throttle sensor 20. It will be done.

Furthermore, as shown in FIG. 2, a water temperature sensor 2 detects the cooling water temperature as the warm-up temperature of the engine E.
1, and a rotational speed sensor 17 that detects the engine rotational speed using ignition pulse information obtained from, for example, the primary negative terminal of the ignition coil 32.

Furthermore, a vehicle speed sensor 24 is provided which detects the vehicle speed using a pulse signal having a frequency proportional to the vehicle speed, and a known reed switch is used as the vehicle speed sensor 24.

Further, a cranking switch 26 is provided as a cranking sensor that detects the engine cranking state, and this cranking switch 26 is turned on (closed) when the starter motor is turned on, and turned off (open) otherwise. This is a switch.

By the way, the air flow sensor 16 detects the number of Karman vortices generated by a columnar body disposed in the intake passage 1 by using ultrasonic modulation means or by detecting a change in resistance value. This detects the amount of intake air in the intake passage 1, and the digital output from the air flow sensor 16 is input to the controller 29. Note that the digital output from the air flow sensor 16 is applied to, for example, a 1/2 frequency divider within the controller 29, and then subjected to various processing.

In addition, it is generally said that the air flow sensor 16 malfunctions due to intake pulsation or the like when the engine E is running at low speed and under high load. However, in this embodiment, an intercooler 8 is provided downstream of the air flow sensor 16, and the dimensions of the air cleaner portion are adjusted accordingly. As a result, the intake pulsation as described above almost no longer occurs, so it is considered that the measurement reliability or accuracy by the air flow sensor 16 is sufficiently high.

In addition to the above-mentioned sensors and switches, there is also an intake air temperature sensor 18 that detects intake air temperature, an atmospheric pressure sensor 19 that detects atmospheric pressure, an O ₂ sensor 22 that detects oxygen concentration in exhaust gas, and a knock sensor that detects engine knock status. 23, Day streamer 33
The crank angle sensor 27 detects the crank angle using a photoelectric conversion means, and the reference opening of the throttle valve 11 (this opening is determined based on the engine speed, for example).
It is set as a small opening corresponding to around 600 rpm. ) is provided with a motor position switch 28 as a position sensor for detecting the position (reference position) of the rod 15 with the actuator 12 corresponding to the motor. Signals from these sensors and switches are input to the controller 29. It is becoming more and more common.

Note that the motor position switch 28 is
As shown in the figure, it is provided behind the rear end surface of the rod 15, and is configured to be on (closed) when the rod 15 is in the most retracted state and off (open) at other times.

In addition, an intake temperature sensor 18, an atmospheric pressure sensor 19,
Since the detection signals of the water temperature sensor 21, throttle sensor 20, _O2 sensor 22, knock sensor 23, etc. are analog signals, they are input to the controller 29 via the A/D converter.

Note that the atmospheric pressure sensor 19 may be incorporated into the controller 29.

Further, an ignition coil 32 is provided, and this ignition coil 32 is connected to a power transistor 3 as a switching transistor.
0, the primary side current is turned on and off.

Furthermore, a display meter 35 is provided in the vehicle interior.

The display meter 35 may have a needle-type display section 35a or a segment-type display section 35b in which light emitting diodes (LEDs) are arranged in a row and these LEDs blink as appropriate. .

By the way, the controller 29 is configured with a CPU, a memory (including a map), and an appropriate input/output interface. When the engine speed is lower than a predetermined value in the state of
7 performs feedback control of the engine rotational speed (rotation speed feedback control), while controlling the position of the throttle valve 11 using a signal from the throttle sensor 20 under other set conditions at the time of detecting the idle state. In order to perform shock feedback control, an idle switch 25, a rotation speed sensor 17, a throttle sensor 2
0. It has the function of an idle control means (first control means) M1 that receives detection signals from the vehicle speed sensor 24 and outputs an idle control signal based on these detection signals to the motor 13 of the actuator 12.

Furthermore, when performing rotation speed feedback control, the target engine speed is changed according to the cooling water temperature as shown in Fig. 4, and when performing position feedback control, the target throttle opening is changed according to the cooling water temperature. is changed as shown in FIG.

Furthermore, the relationship between the driving time ΔD of the motor 13 of the actuator 12 and the deviation ΔN or ΔP is as shown in FIGS. 6 and 7, respectively. Here, the deviation ΔN means the difference between the actual engine speed and the target engine speed, and the deviation ΔP means the difference between the actual throttle opening and the target throttle opening.

Although the above conditions have already been described, this condition refers to a case where at least the following items are satisfied, and refers to a condition in which the engine is relatively stable.

(1) A predetermined period of time has elapsed after the idle switch 25 was turned from off to on.

(2) The vehicle speed is extremely low (for example, 2.5 km/h or less).

(3) The deviation of the actual engine speed (actual speed) from the target speed must be within a specified range.

(4) In vehicles equipped with a cooler, after the cooler relay etc. switches according to the cooler load,
The specified time has elapsed.

Further, the above conditions refer to conditions when the above conditions are not satisfied, the engine is relatively unstable, and rapid feedback control is desired.

Further, the flow of processing by this idle control means M1 is shown in FIG. 9. That is, first, in step A1, various data are input, and then in step A2, it is determined whether the engine is in an idling operating state. If the engine is in an idle operating state (the engine speed is lower than a certain value even though the idle switch 25 is on), take the YES route at step A2, and set the flag S1 to 0 at steps A2' and A2''. ,
After setting S4=0, it is determined in step A3 whether the above condition is met. If the conditions are such that rotational speed feedback control is desired, the rotational speed feedback control mode is selected in step A4.

As a result, engine speed feedback control is performed on the engine E so that the engine speed reaches the target engine speed.

If it is determined in step A3 that the condition is satisfied, the position feedback control mode is selected in step A5.

As a result, position feedback control is performed on the engine E so that the target throttle opening is achieved.

Note that if the answer at step A2 is NO, the process returns.

Further, the flags S1 and S4 will be explained later.

Note that even if any of the above conditions are satisfied, if it is impossible to control the throttle opening below the minimum throttle opening or above the maximum throttle opening, the controller 29 will not output.

Furthermore, the controller 29 has the function of a second control means M2 that moves the rod 15 in the following manner even when an idle operating state is not detected. That is, the controller 29
When the throttle opening is above a predetermined value, the rod 15 is driven in advance to the high throttle opening (two types are selected depending on the state of the throttle opening), and the idle switch 25 is used to control the throttle opening. When it is detected that the valve 11 is in the fully closed position, a dart pot operation is performed to drive the rod 15 to a predetermined low throttle opening (for example, fast idle opening) that is smaller than the high throttle opening. As much as possible, it is possible to receive detection signals from each sensor and send a dart pot control signal based on these detection signals to the motor 1 of the actuator 12.
It also has the function of a doss pot control means (second control means) M2 that outputs output to the Dashpot control means (second control means) M2. Here, the dart pot operation of the rod 15 controlled by the dart pot control means M2 consists of a dart pot standby operation and a dart pot tailing operation.

First, the dart pot standby operation has two stages (mode 1 and mode 2), and if the following conditions are met, the rod 15 is advanced to the respective dart pot standby opening degrees θd ₁ and θd ₂ , and the subsequent dart pots are opened. This is a motion to prepare for the tailing motion.

Here, the conditions for the rod to move forward in mode 1 are that the throttle opening degree stays in a zone where it is greater than or equal to a predetermined value _θ1 for a predetermined period of time (for example, about 0.5 seconds), and the rod to move forward in mode 2 to move forward. The conditions for this are that the throttle opening is at least another predetermined value θ ₂ (>θ ₁ ) and the engine speed stays in a zone where it is at least a predetermined value N ₀ for a predetermined time (for example, about 0.5 seconds) or more. .

The degree of advance of the rod 15 in mode 1 (dashpot standby opening degree θd ₁ ) is the degree of advancement of the rod 15 in mode 2 (dashpot standby opening degree θd ₂ ).
(see Figure 8).

Further, the dart pot tailing operation refers to the operation in which the idle switch 2 is suddenly closed by the sudden closing of the throttle valve 11 after the above-mentioned dart pot standby operation is completed.
5 is turned on, the rod 15 is gradually moved backward toward the fast idle opening degree θi at a desired slope.

Further, the flow of processing by the dumppot control means M2 is shown in FIG. 10.
That is, first, in step a1, various data are input, and then, in step a2, it is determined whether mode 1, mode 2, or mode other than mode 1 or 2 is selected.

If it is determined that the mode is mode 1, the rod 15 is moved forward to the doss pot standby opening degree _θd1 in step a3. If it is determined that the mode is 2, the rod 15 is moved forward to the doss pot standby opening degree _θd2 in step a4.

As a result, the rod 15 is moved forward to a position corresponding to each mode, and as a result, the dart pot standby operation is completed.

Note that if the mode is neither mode 1 nor mode 2, the dart pot is not placed on standby.

After the expected Dash Pot standby operation,
At step a5, the flag S4 is set to 0, but then, when the throttle valve 11 is suddenly closed and the idle switch 25 is closed, the YES route is taken at step a5', and the dart pot tailing operation is started at step a6. It is done. As a result, the throttle valve 11 gradually closes to the fast idle opening degree.

A series of these operating characteristics of the doss pot is shown in FIG.

Furthermore, the controller 29 also has the function of differentiating means D for differentiating the output from the throttle sensor 20.

Further, the controller 29 may include, for example, the rod 15.
If the rod 15 fails to return from the extended state of the dart pot, the engine may become high speed, or if the rod 15 fails to return from the low temperature fast idle extended state to the high temperature transition state, the engine may become high speed. It has the function of an idle sensor failure determining means J that determines whether the idle sensor 25 has failed in order to prevent the idle sensor 25 from occurring or to display the failure state of the idle sensor 25.

That is, this idle sensor failure determination means J
Idle switch 25, throttle sensor 2
0 and the signal from the differentiating means D, the idle operating state is not detected by the idle switch 25 (although the idle switch 25 remains off), but the amount of change dθ/ of the throttle opening θ is dt is smaller than the first set value α ₀ (this α ₀ is set to a small value), and the throttle opening θ is the second set value θ ₀ (this θ ₀ includes the possible range of the rod 15). (which is smaller than full throttle), the idle sensor 2
5 is determined to be a failure and outputs a signal to that effect.

The flow of processing of the idle sensor failure determination means J is shown in FIG. 1.

That is, first, in step B1, data from the throttle sensor 20 etc. is input, and in step B2, the detected amount of change in throttle opening is input.
It is determined whether the state in which dθ/dt is smaller than the first set value α ₀ continues for a predetermined time (for example, 0.5 seconds) and the detected throttle opening θ is smaller than the second set value θ ₀ . .

By the way, if the amount of change dθ/dt in the throttle opening continues to be smaller than the predetermined value α ₀ , it can be estimated that the throttle valve 11 is at the fully closed stop position. It is desirable to confirm that the throttle opening is within the range where the throttle opening can be at the fully closed stop position due to the movement of the rod 15 _.
It is necessary to know that it is smaller than .

In this way, if θ<θ ₀ and dθ/dt<α ₀ are satisfied, it is possible to detect a failure state in which the idle sensor 25 is not turned on even though it should be turned on.

Therefore, if YES is determined in step B2, it is determined that the idle sensor 25 is malfunctioning, and the failure determination flag S1 is set to 1 in step B3.

Also, if step B2 is NO, return.

Further, the controller 29 receives a determination signal from the idle sensor failure determination means J and a signal from the motor position switch 28, and receives a calibration control signal for driving the rod 15 to the reference position where it is retreated when the idle sensor 25 fails. The motor 1
In addition, when the reference position detection signal from the motor position switch 28 is input while the idle sensor failure determination signal from the idle sensor failure determination means J is being input, , failure initial idle opening setting means M4 outputs to the motor 13 an initial throttle opening setting signal for driving the rod 15 to a predetermined initial idle opening state using this reference position detection signal as a trigger signal. It also has functions.

First, the processing performed by the calibration control means M3 will be explained using FIG. 11. That is, in step C1, the motor position switch 28
etc. are input, and in step C2, the flag
It is determined whether S1=1. If the idle sensor 25 is out of order, as is clear from FIG. 1, flag S1=1, so step C2 is executed.
Take the YES route and go to the next step C2' to S4
= 1 is checked. Getting started with S4
Since S4=0, the NO route is taken and in the next step C3, it is determined whether flag S2=1.

Note that even if S1=1, if the processing by the failure initial idle opening setting means M4, which will be described later, is completed and the throttle valve 11 is in the set opening state,
Since S4=1, no processing is performed through the YES route.

Initially, flag S2=0, so step C3
The NO route is taken, and in step C4 it is determined whether the motor position switch 28 is on (closed). Normally, the rear end of the rod 15 is in front of the motor position switch 28, so the motor position switch 28 is off (open). Therefore, in step C4, the NO route is taken, and in step C5, the motor 13 is activated with the pulse width L1.
is driven to drive the rod 15 backward.

Here, since the pulse width L1 is set relatively large, the rod 15 is driven largely backward.

As a result of the rod 15 being moved backward in this way, the motor position switch 28 is turned on (closed). In step C6, the flag S2 is set to 1, and in step C7, the motor position switch 28 is turned off (opened). Since the motor position switch 28 is on at this time, in step C8, the pulse width L2 is
(<L1) to drive the motor 13 and
5 is driven forward.

Here, since the pulse width L2 is set relatively small, the degree of advancement of the rod 15 is small. After this process, the process returns and, for example, when the next timer interrupt signal is input, steps C1 and C are executed again.
2, C2', and C3 are performed, but in this case, since S2=1 is set at step C6,
At step C3, the process jumps to step C7, and then steps C7 and C8 are processed.

In this way, as the rod 15 gradually moves forward, the motor position switch 28
turns off. This causes the rod 15 to take the reference position.

Therefore, after that, the NO route is taken in step C7, and the process of setting S3=1 is performed in step C9. Here, the process of setting the flag S3=1 is a process that indicates that the calibration of the rod 15 has been completed.

Next, the processing performed by the failure initial idle opening degree setting means M4 will be explained using FIG. 12.

That is, first in step D1, flag S1=
1 or not is determined.

When the idle sensor fails, S1=1, so
At step D1, the YES route is taken, and at the next step D2, it is determined whether flag S3=1.

If the calibration of the rod 15 has been completed, that is, if the rod 15 is at the reference position, S3 = 1, so the YES route is taken in step D2, and the adjustment is made according to the set throttle opening in the next step D3. A motor drive time ΔD is set in a timer, and in step D4, the motor 13 is driven until the timer reaches 0.

As a result, the rod 15 moves further forward, and the throttle valve 11 enters a predetermined initial idle opening state.

Further, when the rod 15 advances to a predetermined position and is set to the initial idle opening degree, steps D5 and D
6, D7, D8, S2=0, S3=0, respectively.
Setting S4=1 and S1=0 is performed.

Note that the process of setting the flag S4=1 is a process that indicates that the initial idle opening degree has been set.

In this way, when S4=1, the idle switch 25 is turned on, and according to FIG. 9, S4=0.
Since S4=1 continues until S4=0 in FIG. 10, or until the dart pot waits and S4=0 in FIG. 10, the above-mentioned calibration control and setting control are performed only once. In other words, if the above idle sensor failure judgment is true because the throttle opening happens to be constant, the failure judgment continues to be true even after the above control, but the above calibration control and setting control are performed only once. This makes it possible to avoid deterioration of durability due to unnecessary operation, and disadvantages such as returning the throttle valve 11 during calibration work and unnecessarily reducing the engine speed.

Note that the controller 29 also has a function as a prospective control means (second control means) for causing the rod 15 to project forward at times other than when controlling the dart pot. That is, this prospective control means is used when performing cranking or fast idle. In other words, when you step on the accelerator pedal and start the engine, the ROD 15 is expected to move forward in order to achieve cranking and fast idle in order to prevent the rotation from dropping until the idle speed control is activated when you take your foot off the accelerator pedal. Let it happen.

In such a case, as in the case of dart pot control, due to a failure of the idle switch 25,
Since the rod 15 may not move backward, if the idle switch is malfunctioning, the rod 15 may not move backward.
After returning to the reference position, it is moved forward to the set position. Note that the processing flow in this case is the same as that described in FIGS. 11 and 12.

The controller 29 also includes, for example, a display 35.
If is a boost meter, air flow sensor 1
6. Receives signals from the rotation speed sensor 17, intake temperature sensor 18, and atmospheric pressure sensor 19, information on intake air amount A, information on engine rotation speed N, information on intake temperature T,
It has the function of an intake passage pressure display control means M5 that outputs a signal corresponding to the intake passage pressure P to the display 35 based on information on the atmospheric pressure AP.

Now, focusing on the intake passage pressure display process, the flow of the process performed in the controller 29 is briefly shown in FIG. 13. That is, in step E1 of FIG.
6. Input each data from the rotation speed sensor 17, intake temperature sensor 18, and atmospheric pressure sensor 19, and in the next step E2, intake air amount A and engine rotation speed corrected according to intake temperature T and atmospheric pressure AP are determined. From N,
Calculate A/N.

This A/N is proportional to the density inside the intake passage 1 (density inside the manifold), and the density inside the intake passage 1 is proportional to the intake passage pressure (P/T), so if you know the A/N and the intake temperature T, , since the intake passage pressure P is also known,
Thereafter, in step E3, a drive signal (display signal) corresponding to the A/N having information on the intake passage pressure P as described above is output to the display 35. As a result, the intake passage pressure is displayed on the display 35. In this case, the signal output to the display 35 is a current signal, but may be a voltage signal.

Further, based on the determination signal from the idle sensor failure determination means J, the controller 29 controls the display 35 with priority over the intake passage pressure display control means M5.
It also has the function of a failure display control means M6 that outputs an idle sensor failure indication signal.

Next, the flow of processing mainly performed by the idle sensor malfunction determining means J and the malfunction display control means M6 is shown in FIG. 14.

First, data from various sensors and switches are input in step F1, and then in step F2.
Then, it is determined whether the flag S1 is 1 or not. If the idle sensor 25 is out of order, the flag S1 is set to 1, as can be seen from FIG. 1, so if the idle sensor 25 is out of order, the YES route is selected in step F2.

In this way, if it is determined YES in step F2, it is determined that the idle sensor 25 is malfunctioning, and in step F3, the failure display control means M6 takes priority over the intake passage pressure display control means M5. , a failure indication signal is output to the display 35, thereby causing the display 35 to display that the idle sensor 25 is malfunctioning.

As a method of indicating a failure, for example, the value indicated by the needle is set to a constant value regardless of the operating state. By continuing to point to a constant value in this way, a warning is given that the idle sensor 25 is out of order.

If the result in step F2 is NO, that is, S1=0, then in step F4, the intake passage pressure display control means M5 causes the display 35 to display the normal intake passage pressure. The specific means are as described above.

The controller 29 also includes fuel supply control means that receives signals from the above-mentioned sensors and switches and outputs signals for supplying fuel to the electromagnetic fuel injection valves 9 and 10 in accordance with the operating state of the engine E; An ignition timing control means outputs an ignition timing control signal according to the operating state of the engine E, and a two-diaphragm pressure response device 7 is used to adjust the opening timing of the waste gate valve 6 in order to obtain different boost pressure characteristics. It also has the function of a wastegate valve control means that outputs a signal to the electromagnetic switching valve 24 to be controlled (this valve 24 has a return spring (not shown) for the valve body).

As mentioned above, A/N information has intake passage pressure information, so this is used as engine load information, and the engine operating state is detected from this information and engine speed information to perform fuel supply control, etc. It is being done.

In other words, the air flow sensor 16, rotation speed sensor 17, intake air temperature sensor 18, and atmospheric pressure sensor 19 are not only used to display the intake passage pressure P, but are originally used for electronic fuel supply control. Therefore, an air flow sensor 16, rotation speed sensor 17, etc. are not newly provided to display the intake passage pressure.

Further, instead of using software processing within the controller 29, the differentiating means D may be provided as a differentiating circuit outside the controller 29.

Furthermore, in addition to the boost meter, a device driven by a signal from the controller 29, such as a speedometer or a tachometer, may be used as a display device for indicating a failure.

Incidentally, the reference numeral 36 in FIG. 2 indicates an ignition key switch, and the reference numeral 37 indicates a battery.

Also, in FIG. 2, a line directly connected from the battery 37 to the controller 29 is connected to a backup memory within the controller 29.

〔Effect of the invention〕

As described above in detail, the idle sensor failure determination device of the present invention includes a throttle valve provided in an intake passage of an engine, and an idle sensor that detects the idle operating state of the engine according to the opening and closing of the throttle valve. a throttle sensor that detects the opening of the throttle valve; a throttle valve opening change rate detection means that detects the speed of change in the throttle valve opening; an idle state estimating means for estimating that the engine is in an idle operating state when the throttle valve opening change speed detected by the throttle valve opening change speed detecting means is smaller than a predetermined speed; and a failure determination means for determining that the idle sensor has failed when the idle operation state is not detected by the idle state estimation means and the idle operation state is estimated by the idle state estimation means. , the following effects or advantages can be obtained.

(1) If the idle switch does not detect that the engine is in idle operation, but it detects that the throttle valve opening change rate is smaller than a predetermined value, the idle sensor is determined to be faulty and a signal to that effect is sent. is output, so if the idle sensor fails, for example, the dart pot tailing operation may not start as in the conventional case, or
This prevents a situation in which a high engine rotational state is sustained due to the operation of reducing the throttle opening not starting as the cooling water temperature rises, and as a result, highly reliable engine idle control can be achieved. There are benefits that can be achieved.

(2) When the idle sensor malfunctions, the failure state of the idle sensor is reliably determined and a signal indicating that the idle sensor is malfunction is supplied to, for example, a display means to determine whether the throttle sensor is malfunctioning. It is also possible to reliably display information on whether the engine is running or not, which is advantageous in terms of engine idle control.

[Brief explanation of drawings]

The figures show an engine idle control device having an idle sensor failure determination device as an embodiment of the present invention. Figure 3 is a configuration diagram of its main parts, Figures 4 to 8 are graphs for explaining its actions, and Figures 9 to 1.
Figure 4 is a flowchart for explaining the respective operations. DESCRIPTION OF SYMBOLS 1... Intake passage, 2... Exhaust passage, 3... Turbocharger, 4... Turbine, 5... Compressor, 6... Waste gate valve, 7... Pressure response device, 8... Intercooler, 9, 10... ...Solenoid fuel injection valve, 11...Throttle valve, 11a
...shaft, 11c...throttle lever, 11d...
... Throttle lever end, 12 ... Actuator, 13 ... Motor, 14a ... Worm, 14
b... Worm wheel, 14c... Pipe shaft,
14d... Female thread part, 15... Rod, 15a...
... Male thread part, 15b ... Long hole, 16 ... Air flow sensor, 17 ... Rotation speed sensor, 18 ... Intake temperature sensor, 19 ... Atmospheric pressure sensor, 20 ... Throttle sensor, 21 ... Water temperature sensor, 22...
_O2 sensor, 23...knob sensor, 24...vehicle speed sensor, 25...idle switch as idle sensor, 26...cranking switch,
27...Crank angle sensor, 28...Motor position switch, 29...Controller, 30
... Power transistor, 31 ... Catalytic converter, 32 ... Ignition coil, 33 ... Distributor, 34 ... Electromagnetic switching valve, 35
...Indicator, 35a...Needle display section, 35b...
Segment type display unit, 36...Ignition key switch, 37...Battery, D...Differentiating means, E...Engine, J...Idle sensor failure determination means, M1...Idle control means, M2...
Dashpot control means, M3... Calibration control means, M4... Initial idle opening setting means at the time of failure,
M5...Intake passage pressure display control means, M6...
Control means for fault indication.

Claims (1)

[Claims] 1. A throttle valve provided in an intake passage of an engine, an idle sensor that detects the idle operating state of the engine according to opening and closing of the throttle valve, a throttle sensor that detects the opening degree of the throttle valve, and the throttle valve. a throttle valve opening change speed detecting means for detecting a change speed of the valve opening; and a throttle opening detected by the throttle sensor, which is smaller than a predetermined opening, and a throttle valve opening change speed detecting means detecting the throttle opening. Idle state estimating means for estimating that the engine is in an idling state when the rate of change in valve opening degree is smaller than a predetermined speed; An idle sensor failure determination device comprising: failure determination means for determining that the idle sensor has failed when an idle operating state is estimated.