JPS6147737B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a device (anti-skid control device) that prevents skidding phenomenon that occurs when a vehicle is suddenly braked.
This invention relates to a device that checks for abnormalities in advance.

An anti-skid control device is a device that prevents the wheels from skidding by controlling the hydraulic pressure or air pressure that drives the braking device to prevent the wheels from stopping when the vehicle is suddenly braked. The oil pressure or pneumatic pressure control here is normally an on-off control, which performs on-off operations several to several dozen times in a short period (several seconds to several tens of seconds) from when the brake is pressed until the car stops. Let's do it. Therefore, the response delay time of the anti-skid control device (including the actuator that performs hydraulic or pneumatic control operations) is
It is normal to set it to 100 to 200 ms or less. However, the actuator is a mechanical device and has the possibility of causing the following two abnormal conditions depending on how it is adjusted. First, even though the anti-skid device is operating and applying an on signal to the actuator to turn off the braking force,
The second is a state in which the actuator does not turn on (no-dump state), and the second state is the opposite state to the above, that is, a state in which the actuator does not turn off even though an off signal is applied to the actuator that is in the on-state (overdump state). be. All actuators have some no-dump and over-dump periods, which account for the response delay time of the anti-skid device. Therefore, as mentioned above, the no-dump and over-dump permissible periods are at most 100 ms to 200 ms, and any period longer than that must be checked in advance as an abnormality. Particularly during the overdump period, braking is not applied, so if this period is long, it is extremely dangerous.

Conventionally, a device for detecting the above two abnormal states is not clear.

The object of the present invention is to provide a simple device for checking the above two abnormal conditions in advance. First, before giving detailed explanations based on embodiments, an overview of the present invention will be described.

FIG. 1 is a diagram for explaining the basic concept of the present invention, which will be explained below. At time t = t ₀ , when an on signal (“1”) is input to the actuator drive signal line, after a time delay of T ₁ second,
That is, at (t=t ₁ ), the actuator operates and outputs an operation signal (“1”). This operation signal sets the actuator drive signal to "0",
That is, an off signal is input to the actuator.
Then, after a time delay of T ₂ seconds, ie at t=t ₂ , the actuator outputs a non-operating state, ie a "0" operating signal. T ₁ s and T ₂ s are the above no-dump and over-dump periods, respectively.

Possible methods for detecting an abnormality include a method of measuring T ₁ seconds and T ₂ seconds with a timer, and a method of measuring T ₁ +T ₂ seconds with a timer. The latter has the advantage of simplifying the circuit configuration. In any case, the feature of this method is that the time required for checking is approximately T ₁ +
T It's as short as ₂ seconds.

Next, the present invention will be explained in detail with reference to Examples.
FIG. 2 shows an embodiment of the method for detecting the above-mentioned T ₁ +T ₂ seconds. In the same figure, SR flip-flop 1
Assuming that 2 and 2 perform the logical operations shown in FIG. 4, the signal waveforms at points a to e in the figure become as shown in FIG. First, before the check starts, if the check signal a is "1", then the flip-flop 1
The output Q of the NOR element 3 is "0", and the output of the NOR element 3, that is, the actuator drive signal C is "0". Therefore, since the actuator operation signal b is "0" and the output of the inverter 4 is "1", the output Q of the flip-flop 2 is "0" and the timer 5 does not operate. Next, when the check starts, when the signal a becomes "0", the signal C becomes "1", so an on signal is input to the actuator, and at the same time, the signal d becomes "1", and the timer starts operating. Time delay from start of check
After _T1 seconds, the actuator is turned on, signal b becomes "1", resets flip-flop 1, and at the same time sets the reset signal of flip-flop 2 to "0". Almost at the same time, the signal C also becomes "0" and an off signal is input to the actuator. Here, the signal d is in the previous state, that is, "1"
Retain state. After a time delay T _{of 2} seconds, the actuator turns off and signal b becomes “0”, so
The flip-flop 2 is reset, the signal d becomes "1", and the timer stops operating. If the time set in the T ₁ +T _2- second timer is longer than the time (abnormality determination time), the timer outputs an abnormality detection signal and the abnormality can be detected.

Here, an oil lamp signal is used as the check signal a. In other words, when starting an automobile's prime mover, an oil lamp signal is always generated until the oil pressure of the prime mover reaches the specified value, and when the starting of the prime mover is completed normally and the oil pressure reaches the specified value, the oil lamp signal becomes 1. Returns to 0. At this time, the above-mentioned check is started. Therefore, it is convenient because the check can be performed automatically when starting the vehicle.

Further, in FIG. 2, it can be easily inferred that if a timer circuit similar to the timer circuit 5 is installed at the output of the signal C and the signal b, the times T ₁ seconds and T ₂ seconds can be detected individually.

As described above, according to the device of the present invention, the time required for checking is short, the specific circuit configuration is simple, and the anti-skid check is performed in advance at the time of starting the vehicle rather than at the time of actual braking. This has the advantage of checking for abnormalities in the actuator of the control device, and the effect is extremely significant.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the concept of the present invention, FIG. 2 is an embodiment of the present invention, and FIG. 3 is a time chart of signals at various parts in FIG. FIG. 4 is a logic diagram of the operation of a flip-flop. 1, 2: flip-flop, 3: NOR element,
4: Inverter, 5: Timer circuit.

Claims (1)

[Claims] 1. In an anti-skid control device having an actuator that intermittently controls braking oil pressure or air pressure to intermittently turn off the braking force when braking a vehicle, outputting a drive signal to the actuator in response to an oil lamp signal of the vehicle; A circuit that turns off the drive signal in response to a drive completion ON signal for the actuator, a time from generation of the drive signal to generation of the drive completion ON signal, and generation of the drive OFF signal for the actuator;
1. An abnormality detection device for an anti-skid control device, comprising a check device comprising a timer circuit for detecting each of the times until generation of a drive completion off signal resulting from this, or the sum of both.