JP2799800B2 - Failure detection device for brake detection means - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a failure of a brake detecting means mounted on a vehicle for detecting whether or not a brake is applied.

[0002]

2. Description of the Related Art Conventionally, a brake switch interlocked with a brake pedal is provided as brake detection means, and a signal from the brake switch is input to an electronic control circuit for engine control to control the engine in accordance with a brake operation state. What is known is known (see JP-A-61-271131). However, conventionally, there is no means for detecting a failure of the brake switch, and a signal different from the actual operation state of the brake is input to the control circuit from the brake switch, and the engine is appropriately operated according to the operation state of the brake. Sometimes became uncontrollable.

[0003]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an apparatus capable of detecting when a brake detection means has failed.

[0004]

In order to achieve the above object,
The present invention is an apparatus for detecting a failure of a brake detecting means mounted on a vehicle for detecting whether or not a brake is operated, and detecting an engagement state of a transmission means for transmitting an output of an engine. 1 detecting means, 2nd detecting means for detecting vehicle speed, and 3rd detecting means for detecting engine load
And fourth detecting means for detecting an engine speed, and a transmission hand.
That the stage is in gear to transmit engine power
The first detecting means detects and the third detecting means detects.
The detected engine load and detected by the fourth detecting means.
The engine speed is equal to or more than a predetermined value, and
When the vehicle speed detected by the detection means is a value indicating the stop
The brake detection means outputs a signal indicating the operation of the brake.
If not, it is determined that the brake detector is off.
Separately, the acceleration rate of the vehicle speed detected by the second detection means is calculated.
And the engine load detected by the third detection means and the fourth detection means
The degree of increase in engine speed detected at each stage is predetermined
When the value is greater than or equal to the value, the brake detection means activates the brake
Is output, the brake detection means is turned off.
Determining means for determining that the failure has occurred.

[0005]

[ Function ] The transmission means is in gear, engine load and engine
And the vehicle speed is stopped.
All of the conditions are met when the engine moves the vehicle.
Output that is transmitted to the vehicle drive.
Absolutely brakes are activated when the vehicle does not move
According to the present invention.
Fault in the key detection means (indicating brake operation by disconnection etc.
Failure signal is not output)
Therefore, the off failure can be accurately detected.

[0006] In addition, the acceleration of the vehicle speed, the engine load and the air
The increase in the engine speed exceeds the specified value.
Indicates that the vehicle is actually accelerating with the engine
When the brakes are not working,
According to the present invention, this is because the brake detection means is ON.
Failure (continuous output of signal indicating brake operation due to contact welding, etc.)
On-failure)
Can be detected reliably.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the illustrated embodiment, the present invention is applied to a failure detecting device for a brake detecting means comprising a brake switch which is turned on by depressing a brake pedal.
As shown in FIG. 1, an electronic control circuit (hereinafter referred to as ECU) 1 includes:
A signal from a brake switch 2, a signal from a position sensor 3 of a shift lever of a transmission as a transmission means for transmitting an engine output, and a vehicle speed sensor 4 for detecting a vehicle speed V
Signal and one parameter representing the engine load
A signal from a throttle sensor 5 for detecting a certain throttle opening θth, a signal from a rotation sensor 6 for detecting the engine speed Ne, and other parameters representing the engine load.
A signal from a pressure sensor 7 for detecting an intake pipe internal pressure Pb, which is a meter, and a signal from a side brake sensor 8 for detecting an operation of a side brake are input, and the ECU 1 determines whether the brake switch 2 has failed. I made it. The present embodiment is applied to an automatic vehicle. In a manual vehicle, a neutral switch or a clutch switch is used instead of the position sensor 3.

The program for detecting the failure of the brake switch 2 is as shown in FIG. 2. First, in step S1, the transmission enters the neutral range (N) or the parking range (P) based on the signal from the position sensor 3. It is determined whether the transmission is in an in-gear state other than N and P, and the process proceeds to step S2 to determine whether the side brake is operating. If the side brake is not operating, the process proceeds to step S3 to determine whether or not the throttle opening θth is equal to or greater than a predetermined value.
If Ne is equal to or greater than the predetermined value, the process proceeds to step S4 to determine whether the engine speed Ne is equal to or greater than the predetermined value. If Ne is equal to or greater than the predetermined value, the process proceeds to step S5 to determine whether the vehicle speed V is zero. Determine. The process proceeds to the step S5 because the transmission is in the in-gear state, the engine output is transmitted to the drive wheels, and the engine operation state is generating an output sufficient to move the vehicle, and the side brake is not applied. At this time, the vehicle speed V becomes zero only when the brake is operated by depressing the brake pedal, and if the brake switch 2 has not failed, the ON signal from the brake switch 2 is sent to the ECU 1. Should be entered. Therefore, when V = O, the process proceeds to step S6, where it is determined whether or not the brake switch 2 is on.
After a lapse of a predetermined time from step 7, the process proceeds to step S8, in which it is determined that the brake switch 2 has caused an off failure such as disconnection, and appropriate fail-safe processing such as displaying the fact is performed.

If the process does not proceed to the step S8, the process proceeds to a step S9 to determine whether or not the acceleration sum .DELTA.V of the vehicle speed V is equal to or greater than a predetermined value.
Proceeding to step 10, it is determined whether or not the throttle opening θth is equal to or greater than a predetermined value.
Proceeding to step 11, it is determined whether or not the intake pipe internal pressure Pb is equal to or higher than a predetermined value. If Pb is equal to or higher than the predetermined value, the flow proceeds to step S12 to determine whether the degree of increase in engine speed △ Ne is equal to or higher than a predetermined value. Is determined, and if △ Ne is equal to or greater than a predetermined value, S1
Proceeding to step 3, it is determined whether the brake switch 2 is on. The process proceeds to step S13 when the engine is in an accelerating operation state and the vehicle is actually being accelerated, and when the brake should not be operating. At this time, the brake switch 2 is turned on. It can be determined that an ON failure such as welding has occurred. But one
If the brake switch 2 is determined to be ON in step S13, the determination is not performed.
Proceeding to step 14, the count number C of the NG counter, which is reset to zero when the engine is started, is incremented by one, and S1
If it is determined in step 5 that the count number C has become equal to or greater than the predetermined value, the process proceeds to step S16, in which it is determined that an off failure of the brake switch 2 has occurred, and an appropriate fail safe such as displaying the fact is displayed. Perform processing.

In the case of a manual vehicle, the state of the transmission and the state of the clutch are determined based on the signals of the neutral switch and the clutch switch in step S1, and the transmission is in a state other than neutral and the clutch is connected. If the process proceeds to step S2 while the vehicle is in operation, a failure of the brake switch can be detected by the same program as described above.

Further, the ECU 1 may be used for controlling the engine, and the above-described program for detecting a failure may be executed in a subroutine. Can also be applied.

[0012]

As is apparent from the above description, according to the present invention, when an off-failure or on- failure of the brake detecting means has occurred, it can be reliably detected. Conventionally used for controlling the engine and the like such as the engagement state of the transmission means, the vehicle speed and the operation state of the engine, there is no need to provide a special sensor only for failure detection, which is advantageous in cost. .

[Brief description of the drawings]

FIG. 1 is a block diagram of an example of the apparatus of the present invention.

FIG. 2 is a flowchart showing a failure detection program.

[Explanation of symbols]

Reference Signs List 1 ECU (discriminating means) 2 Brake switch (brake detecting means) 3 Position sensor (first detecting means) 4 Vehicle speed sensor (second detecting means) 5 Throttle sensor (third detecting means) 6 Rotation sensor ( fourth detecting means) 7. Pressure sensor (third detection means)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-160924 (JP, A) JP-A-63-113360 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60T 17/22

Claims (1)

(57) [Claims] 1. A device for detecting a failure of a brake detection means mounted on a vehicle for detecting whether or not a brake is operated, wherein the engagement state of a transmission means for transmitting an output of an engine is detected. First detecting means, second detecting means for detecting vehicle speed, and third detecting means for detecting engine load.
Stage, fourth detecting means for detecting the engine speed, and transmission
Means are in-gear, transmitting engine power
Is detected by the first detection means, and the third detection means
Detected engine load and detected by the fourth detection means
Engine speeds are each equal to or greater than a predetermined value, and
2 When the vehicle speed detected by the detection means is a value indicating that the vehicle has stopped
The brake detection means outputs a signal indicating the operation of the brake
If the brake detection means is an off failure when not
Discriminate, and further, the acceleration of the vehicle speed detected by the second detecting means.
And the engine load detected by the third detection means and the fourth detection
The degree of increase in engine speed detected by the means is
The brake detection means
When the brake detection means outputs a signal indicating
A failure detecting device for a brake detecting means, comprising: a determining means for determining that an ON failure has occurred.