JPS6042057B2 - Failure detection device for vehicle anti-skid device - Google Patents

Description

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! This invention relates to a failure detection device for a vehicular anti-skid device that controls the braking pressure of the wheels in order to prevent the vehicle from skidding.

Generally, anti-skid devices for vehicles are required to have sufficient reliability because they control braking pressure using wheel rotational speed as an input signal. By the way, if the anti-skid device breaks down, depending on the failure mode, the brakes may stop working, or
The anti-skid device may malfunction without the driver's knowledge, creating a very dangerous situation. For this reason, an abnormality detection circuit is generally provided to detect an abnormal state of each component that makes up the anti-skid device, and when an abnormality is discovered, a failure processing circuit is activated to forcibly disable the operation of the anti-skid device. A warning is issued to the driver as soon as the system is activated.

Furthermore, in order to ensure safety, the system was configured so that everything from abnormality discovery to failure handling was carried out promptly, and abnormality signals were stored.

For this reason, even in a situation where normal operation can be expected after a momentary abnormality occurs in the components constituting the anti-skid device, the abnormal state is memorized and the failure processing circuit is activated. For example, when monitoring for poor contact in connectors used for electrical connections between parts that make up an anti-skid device, when a vehicle occasionally encounters strong shock vibrations, contact may temporarily become poor and abnormalities occur. A signal is generated.

If failure processing is performed due to such a momentary accidental abnormality, there is a drawback that a sense of uneasiness remains because the cause cannot be discovered. This invention improves the above-mentioned drawbacks and does not activate the failure processing circuit for abnormalities where normal operation can be expected after an instantaneous abnormality, but when a dangerous abnormality occurs, it can be operated as quickly as the conventional device. An embodiment of the present invention shown in the drawings will be described below. In the figure, 1 is an abnormal signal generation circuit that detects the abnormal state of each component constituting the anti-skid device and generates an abnormal signal, and 2 is a timer circuit that detects the duration of the abnormal signal and generates a failure signal.
It consists of a comparator 3, a resistor 4, and a capacitor 5.

6 is a brake switch that turns 0FF during control and 0N when not braking.
It is configured to do so.

Reference numeral 7 denotes a storage circuit for storing the failure signal generated by the timer circuit 3, and is constructed using, for example, a flip-flop circuit.
will be accomplished.

Reference numeral 8 denotes a failure processing circuit, which is configured to forcibly deactivate the anti-skid device and issue a warning to the driver when a failure condition is stored in the memory circuit 7.

Next, let's talk about the operation of the device configured as above. This will be explained in detail.

First, the abnormality signal generating circuit 1 generates a voltage at the output terminal of the abnormality signal generating circuit 1 as an abnormality signal when an abnormality occurs in the anti-skid device.

Here, when the brake is not applied, that is, when the brake switch 6 is ON, the capacitor 5 is charged via the resistor 4 by the output voltage, and the potential of the capacitor 5, that is, the potential of the non-inverting terminal of the comparator 3, is on the inverting side. When the reference potential set at the terminal is reached, the comparator 3 generates a failure signal.

That is, when the abnormal signal continues for a set time or more except during braking, a failure signal is generated. However, during braking, that is, when the brake switch 6 is OFF, the capacitor 5 is in an open state, and as soon as an abnormal signal is generated, the potential of the non-inverting input of the comparator 3 reaches the reference potential set at the inverting terminal, and the comparator 3, a failure signal is generated.

Therefore, the brake switch 6 is 0N except during braking when the anti-skid device does not actually operate, and even if an abnormal signal is generated temporarily in this state, the failure will occur unless the abnormal signal continues for the time set by the timer circuit 2. Since no signal is generated, if the set time a is set longer than the time during which the instantaneous accidental abnormality occurs, no failure signal will be generated even if the instantaneous accidental abnormality occurs.

If a continuous failure occurs, detection of the failure will be delayed by the time set in the timer circuit 2, but since the anti-skid device does not operate during non-braking, there is no problem with safety at all.

On the other hand, during braking, the brake switch 6 is turned OFF, and when an abnormal signal is generated, a failure signal is generated immediately, ensuring safety. Further, when a failure signal is generated from the timer circuit 2, the failure signal is stored in the memory circuit 7, and the failure processing circuit 8 forcibly deactivates the anti-skid device and issues a warning to the driver. In the above-described embodiment, the setting time of the timer circuit 2 is changed depending on the operation mode of the brake switch 6.
The same effect can be obtained even if the setting time is changed in conjunction with the operation of the anti-skid device. As described above, the present invention is capable of changing the setting time of a timer circuit from generation of an abnormal signal to generation of a failure signal in conjunction with the operation mode of a brake switch activated during braking or the operation of an anti-skid device. This has the advantage that failures can be reliably detected and safety-related failures can be immediately handled from the occurrence of an abnormality to failure processing. Furthermore, since it can be configured with a very simple circuit, it has many practical advantages.

[Brief explanation of drawings]

The figure is a configuration diagram showing an embodiment of the present invention.

Claims (1)

[Claims] 1. An abnormality signal generation circuit that detects an abnormal state of an anti-skid device and generates an abnormal signal, detects the duration of the abnormal signal, and generates a failure signal when the duration reaches a set time or more. A brake switch comprising a timer circuit that generates a fault signal and a failure processing circuit that forcibly deactivates the device and displays a failure state when the failure signal is generated, and that activates the set time of the timer circuit when braking, or A failure detection device for a vehicle anti-skid device, characterized in that the device changes in conjunction with the operation of the anti-skid device. 2. Claims characterized in that the timer circuit is constituted by a capacitor that is charged via a resistor by the output of the abnormal signal generating circuit, and a comparator that uses the potential of the capacitor as the input potential of its non-inverting terminal. A failure detection device for a vehicle anti-skid device according to item 1.