JPS5853552A - Trouble detecting device of antiskid controlling system - Google Patents

Abstract

PURPOSE:To simplify the configuration of antiskid controlling circuit and the like by a method wherein an AND gate fetches the AND of the two controlling signals of antiskid controlling circuits and a trouble detection signal is issued when the ''H'' level output of fetched outputs continues for the fixed time being. CONSTITUTION:When the controlling signals EV and AV remain in ''H'' level due to the breaking of wire of a wheel speed sensor 10a, trouble of electronic element of the antiskid controlling circuit 14a and the like, an OR gate 24a issues an ''H'' level output and, when said ''H'' level output continues for more than the predetermined period of time, a timer 26a sets, through an AND gate 28, an RS flip-flop 30 in order to light an alarm lamp 34 and simultaneously to deenergize a relay coil 32. The deenergization of the relay coil 32 causes to turn OFF the solenoids 18a, 18b, 20a, 20b, 22a and 22b of hydraulic actuator 16, resulting in returning to realize the normal braking performance. Furthermore, also when either one of the signals EV and AV, the remaining antiskid controlling circuits 14b and 14c similarly actuate as the circuit 14a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an anti-skid control system in which two control signals (&V, AV (g) barrier pressure'l) output from an anti-skid control circuit during braking are respectively applied. System J
The present invention also relates to a failure detection device for an anti-skid control system that is capable of detecting a system failure due to an abnormal output of the control signal with a simple circuit configuration.

Conventionally, in this Yuzu anti-skid control system, the slip ratio (9, 15 to 02) that prevents wheel locking that occurs during braking and obtains maximum braking efficiency.
In order to control one wheel speed so that , hold, and depressurize.

By the way, such an amplifier skid control system r (
For example, as shown in FIG. 1, the output circuit 2 outputs E from one wheel speed sensor 1 (shown as a representative of one wheel) during control.
This EV is achieved by combining the outputs of the V-multiplied signal AV signal.

The brake oil pressure control mode using the AV signal is determined, for example, as shown in Table 1 below.

Table-1 These KV and AV signals are applied to the power transistors Try and Tr, respectively, and the transistors
The brake hydraulic pressure is increased, maintained, and decreased by driving the electromagnetic solenoids 3m and 3bi of the hydraulic actuator by turning on and off Tr, , and Trt.

By the way, with such an anti-skid control system,
If the wheel speed sensor 1 that inputs the wheel speed signal to the anti-skid control circuit 2 is disconnected or short-circuited, or if the circuit board of the anti-skid control circuit 2 is malfunctioning, the hydraulic pressure will be adjusted to ensure maximum braking efficiency. There is a possibility that the control signal is not calculated and output, and a control signal that holds (EV=H, AV=L) or depressurizes (EV=I (, AV=H), for example, is output and remains at 9).

Therefore, in order to detect a failure in which the Ev and/or AV signal is not output correctly, timers 4m and 4b are provided which output when the H level output of the Ev and/or AV signal continues for a predetermined time or more, as shown in FIG. When the output of either one of the timers 4a and 4b is taken out via the OR gate 5, a failure alarm and a rounded 7-turn operation to return to normal braking are performed. However, in this type of anti-skid control system, it is generally required to provide the circuit shown in Figure 1 for each wheel to be anti-skid controlled, so the KEY, AV for each control channel is
It is necessary to provide a failure detection circuit having timers 4a and 4b to monitor each signal, and therefore two timer circuits are required for each channel, which complicates the circuit configuration of the entire system and increases cost. The problem was that it was easy to get expensive.

The present invention has been made by focusing on such conventional problems, and it increases, maintains, and decreases brake hydraulic pressure based on a combination of two control signals output from a 1-amp skid control circuit during control. In an anti-skid control system that performs this, in order to be able to detect an abnormality in the output of each of the control signals with a simple circuit configuration, when the output of at least one of the control signals continues for a predetermined period or longer, It is an object of the present invention to solve the above problems by outputting a failure detection signal.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a circuit block diagram showing one embodiment of the present invention.

First, to explain the configuration, 10a, 10b, and 10C are wheel speed sensors provided for each wheel to be subjected to amplifier skid control;
2 is a hydraulic control signal (EV) for obtaining maximum brake efficiency in the anti-skid control circuit.

AV signals) for each channel of the wheel speed sensors 10 & - 10c.

Anti-skid 1III# In the circuit section 12, 14
a to 14b and 14c are anti-skid control circuits; taking the anti-skid control circuit 14a as an example, the circuits are used to increase, maintain, and reduce the brake hydraulic pressure based on the wheel speed signal from the wheel speed sensor 10a. Ev Gogo and A
Position to output V signal, increase pressure at EV=AV=L, EV=H.

The pressure is maintained at AV=L, and the pressure is further reduced when EV=AV=Fl.

The brake hydraulic pressure control mode based on the combination of the EV and AV signal outputs is controlled by other anti-skid control circuits 14b,
The same applies to 14c.

The outputs of anti-skid control circuits 14a-14c include:
Power transistors "rIlt Tr, , 'rr, , e Trtt and Try," which are turned on and off by EV and AVm.

T rst is provided, for example a power transistor Trl
Taking leT rtt as an example, each collector has a wake-up solenoid 18a of the hydraulic actuator 16;
bta continues. Another power transistor T r,.

Similarly, for ~'frs, VC, the electromagnetic runoids 20a, 20b, and 22a of the hydraulic actuator 16.

22b is connected.

On the other hand, as a failure detection means of the present invention provided in the anti-skid control circuit 1zK, the EV, AV for each channel
OR gates 24a and 24b into which the double signals are input,
2'4c is provided, and the or gates 24a to 2 of KotL et al.
Each output of 4c is input to each of the timer circuits 26m, 26b, and 26e, and the outputs of the timer circuits 26a to 26c are taken out by the OR gate 28 and sent to R8-FF30.
connected to the set input.

The Q output of R8-FF30 is also the transistor Tr.

The transistors Tr4 and Tr6 have a warning lamp 34 connected to their collectors, and are configured to apply electric current 6111+Vl when the switch contact 36 is closed by turning on the ignition switch. Also, the Q output of R8-FF30 is the transistor 'rra(1
A relay coil 32 is connected to the collector of the transistor Tr4, and the relay contact 32a of this relay coil 32 can cut off the supply of the power voltage element 1 to the electromagnetic solenoids 18a to 22b of the hydraulic actuator 16. That's what I do.

The set times of the timers 26a to 26c provided in the anti-skid control concave passage section 12 are set to a predetermined time longer than the time during which brake oil pressure is maintained and reduced in a normal anti-skid control cycle.

Next, the operation of the embodiment shown in FIG. 2 will be explained.

Now, if the EV and AV double signal outputs remain at H level due to a disconnection of the wheel speed sensor 10a or a malfunction of the electronic element constituting the anti-skid control circuit 14a, the OR gate 24a will output an H level output. arises,
When this H level output continues for a predetermined time or more, timer 2
6a generates an H level output through the AND gate 28 and sets R8-FF30, and its Q output becomes H level, turning on the transistor TrSO and lighting the alarm lamp 34, indicating that there is a failure in the system. Inform the driver of what has happened. At the same time, the i output of KR8-FF30 goes to L level, and the transistor T that was turned on until then turns off.
r4 is turned off, the relay coil 32 is deenergized, the previously closed relay contact 32a is opened, the power supply to the electromagnetic runoids 18a to 22b of the hydraulic actuator 16 is cut off, and the brake is forcibly returned to normal braking. Perform fail-safe operation.

On the other hand, the EV output from the anti-skid control circuit 14a
, AV multiplication signal remains at H level, the OR gate 2 is activated as in the case described above.
When the H level output of 4a continues for more than a predetermined time, timer 2
6a generates an H level output, lights up the alarm lamp 34, and opens the relay contact 32m to perform fail-safe operation to return to normal braking.

The failure detection at the time of a system failure in which the EV and AV multiplied signal outputs are at H level is carried out in the same way as for the other anti-skid control circuits 14b and 14e. In this way, in the present invention, for each control channel of each wheel speed sensor, there is one OR gate that extracts the logical sum of EV and AM damage signals, and when the H level output of this OR gate continues for a predetermined time or more, the OR gate is output. Only one timer circuit is required, and even if the number of control channels increases, the circuit configuration of the failure detection device can be simplified and the cost can be reduced.

FIG. 3 shows another embodiment of the present invention, in which the brake hydraulic pressure is increased, maintained, and reduced by the current of the power transistor driven by the combination of EV and AV multiplied signals of the anti-skid control circuit. It is characterized by being controlled.

That is, anti-skid control circuits 14a and 14b.

The outputs of .
0b, . . . are provided, and taking the control channel of the wheel speed sensor 10a as an example, EV=AV=L
When increasing the pressure, the current control circuit 4Oa turns off the power transistor 'rrss and turns off the hydraulic actuator 16.
The driving current of the electromagnetic solenoid 18 is O ampere, and E
When holding V=)I and AV=L, the drive current of the power transistor Trll is controlled to be 2 amperes, and when the pressure is reduced to EV=AV=H, the drive current of the power transistor TrH is controlled to be 2 amperes. The current is controlled so that the current is 4 amperes. In addition, current control circuits 4゜a, 40b, -
-Kld part 2 register Tr, .

The detected drive current value detected by a small resistor r connected to the emitter side of TR□, . l, Tr□.

The driving current of the electromagnetic solenoids 18 to 22 flowing K is maintained at a constant fkK.

In this way, the current trl11 of the power transistor +
The failure detection circuit of the present invention shown in FIG. 2 can be used as is in the Anna skid control system that increases, maintains, and decreases the brake hydraulic pressure from K, and the outputs of the amplifier skid control circuits 14a and 14b. EV to do,
The H level output of at least one of the AV signals is taken out by the OR gates 24a, 2414, . When the transistor TrH is turned on, the alarm lamp 34 is turned on, and when the transistor Tr4@ is turned off, the relay coil 32 is deenergized, and one relay and one contact 32m are opened to supply power to the electromagnetic solenoids 18 to 22 of the hydraulic actuator 16. There is pressure to shut off the power and perform fail-safe operation.

Note that the reset of R8-FF30 shown in the embodiment of FIG. 2.3 is performed by turning on the ignition switch.

As explained above, according to the present invention, there is provided an anti-skid control system that increases and decreases brake hydraulic pressure based on a combination of two control signals output from an anti-skid circuit. , an AND gate that calculates the logical sum of the control signals for each channel of the wheel speed sensor so as to output a failure detection signal when at least one of the control signals continues for a predetermined time period or more; By providing a timer circuit that outputs when the AND gate's "H" level output continues for a certain period of time, the configuration of the failure detection circuit provided for each control channel is simplified, and the number of tables for each control channel is reduced to two. Compared to a conventional device having two timer circuits, the circuit configuration of the entire system is simplified and a highly reliable anti-skid control system can be provided at a low cost.

[Brief explanation of drawings]

Fig. 1 is a circuit block diagram showing an example of a conventional device, Fig. 2 is a circuit block diagram showing an embodiment of the present invention, and Fig. 3 is a circuit block diagram showing an example of a conventional device.
The figure is a circuit block diagram showing another embodiment of the present invention. t, toa~10C...Wheel noodle sensor 2.14a~1
4b...Anti-skid control circuit 3a, '3b,
18, 18m, 18b, 20, 20a, 20b
, 22 m 226 *22b...Electromagnetic solenoid 4m, 46.26a~26e...Timer 5.24a~
24c, 28" OR gate 12...Anti-skid control circuit section 16...Hydraulic actuator 30...R8-FF32...Relay coil 32g.
...Relay contact 34...Warning lamp 36...Ignition switch 40a, 40b...Current control circuit Patent applicant Nissan Motor Co., Ltd.

Claims (1)

[Claims] Anti-skid control that sequentially increases, maintains, and decreases brake hydraulic pressure during each skid cycle based on a combination of outputs of two control signals output from an anti-skid control circuit during braking. In the system, a signal detection means outputs when at least one of the above control signals is output, and a failure detection means outputs a failure detection signal when the output of the signal detection means remains low for a predetermined time or more. A failure detection device for an Anna Skid tlilJ system, characterized in that it has means.