JPS6013858B2 - Fault indication circuit for skid prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a skid prevention device and a failure display circuit for use when a failure detection section thereof is distant from a failure display section, and is particularly useful in skid prevention devices for trucks and trailers. It is something.

Conventionally, for skid prevention devices, various methods have been proposed to detect and display, for example, disconnections and short circuits in wheel rotation sensors, failures in control circuits, failures in brake pressure control mechanisms, etc., but the specific circuit configurations of these methods are The circuit becomes complicated due to the excessive number of parts, which causes problems such as a high failure rate of the circuit itself and a lack of reliability.It is suitable for practical use as a failure indication circuit for skid prevention devices that are used under poor operating conditions. It wasn't.

Furthermore, in the past, disconnection of the power supply lead wire to the skid prevention device, disconnection of the IJ lead wire from the failure detection section to the failure display section,
Or, relatively easy-to-occur and serious failures such as forgetting to connect a connector were not taken into account at all, resulting in many inconveniences when using the skid prevention device.

In view of the above-mentioned conventional drawbacks, the present invention can indicate a failure even if either the failure indication lead wire or other lead wire is disconnected, and the circuit configuration is very simple and is fully practical. The present invention provides a failure indicating circuit for a control device that can withstand

FIG. 1 is a configuration diagram showing a positional relationship when a skid prevention device and its failure detection unit are separated from the failure detection unit in terms of distance.

1 is the skid prevention device and failure detection unit, 2 is the failure display unit “B is the power supply, G is the skid prevention device and failure detection unit”
The end of the power supply B is grounded to a common potential with the fault display section 2, S is a switch that turns on and off all circuits including the fault display section 2, a is a power supply lead, and b is a fault display lead. It is a line.

FIG. 2 is an electrical circuit diagram showing an example in which the failure indicating circuit of the skid prevention device of the present invention is implemented in the positional relationship shown in FIG. Note that in FIG. 2, parts that are the same as those in FIG. 1 are indicated by the same reference numerals. The output stage transistor tortoise 2 of the failure detection part of the skid prevention device has a collector coupled to a power supply lead wire a via a resistor tortoise 3 and a tortoise wing, and an emitter thereof to ground.

In the failure indicator 2, the tri-relay 23 has a normally closed contact 23-1 that switches the power supply lead a side and a normally open contact 23-1 that switches the failure indicator light 24 side.

The transistor 22, whose collector is grounded via the relay 23, has its base coupled to the connection point between the resistor 11 and the resistor 3 via the failure indicating lead b.

Here, if you select the values of resistor 11 and resistor 3 so that they are the mother value of resistor 2, you can set the transistor 2 to shut off when the skid prevention bag is normal. If there is no abnormality in the lead wire a to lead wire b for failure indication, the transistor 22 is cut off, and therefore the relay 23
The normally closed contact 23-1 side is switching, and the power supply lead wire a is energized through this.

In this way, the power supply 8 to the skid prevention device and fault detection unit 1 is
supply is maintained. If there is a failure in the skid prevention device 1 and the transistor becomes conductive, the base potential of the transistor 22 decreases due to the voltage drop caused by the resistor SI', and the transistor 22 becomes conductive.The relay 23 is driven and the normally closed contact 23 is turned on. The normally open contact 23-1 is opened at the same time as the i side is opened and the supply of power B to the skid prevention device 1 is stopped.
switches and lights up the failure indicator light 24.

At this time, the resistor inserted between the base of the transistor 22 and the emitter is opened in a circuit-like manner, so the base current of the transistor 22 flows through the emitter → the base → the resistor 2. Regardless of whether the transistor 12 is conductive or disconnected, the transistor 22 maintains its conductive state and continues to light up until the failure indicator light 2W is turned off. However, if the power supply lead a or the fault indication lead b (or both a and b at the same time) is disconnected, the base current of the transistor 22 will change from emitter to
Because it flows from the base to the resistor 2, the transistor 2
2 becomes conductive and drives the relay 23, which in turn lights up the failure indicator light 24.

In this way, if either one of the lead wires a or b is disconnected, the bias of the transistor 22 is different from that in the case where there is no disconnection, so the indicator light 24 lights up at the time of the disconnection. According to the fault display circuit of the skid prevention device of the present invention, the fault display drive circuit is connected between the fault display lead wire and the other IJ wire, for example, the power supply lead wire, which are interposed between the fault detection section and the fault display circuit. Since it is determined by the bias, even if either the lead wire for fault indication or any other lead wire is broken, the bias will be affected and the fault display will be activated, so the fault display will be wider and the skid prevention system will be affected. This is more effective in improving overall reliability.

According to the present invention, since the display drive circuit is particularly configured to be shared to detect a disconnection, a dedicated disconnection detection circuit is not required at all.

As a result, the number of parts is reduced, and by combining the circuits of Nobutaka and Aitoshi, it is possible to provide a circuit that is sufficiently practical as a failure indicating circuit for a skid prevention device.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram illustrating the positional relationship when the skid prevention device and the failure detection unit and failure display unit are separated by distance, and FIG. 2 is an embodiment of the failure display route of the skid prevention device of the present invention. FIG. Kawama skid prevention device and failure detection unit, 2 is the failure display unit, a is the power supply lead wire, b is the failure indication lead wire, turtle wings and turtle 3 are resistors, 12 and 22 are transistors, 2
3-1 and 23-1' are a normally open contact and a normally closed contact of the relay 23, and S is a switch. Figure 1 Figure 2

Claims (1)

[Claims] 1. A power supply lead wire for connecting the skid prevention device to a power source, and a first transistor that is cut off when the skid prevention device is normal and becomes conductive when the skid prevention device malfunctions, the collector of which is connected to the first resistor and the first transistor is coupled to the power supply lead through a second resistor and has an emitter grounded; the first resistor and the second transistor;
A lead wire for failure indication is derived from the connection point of the resistor,
a second transistor whose emitter is connected to the power supply lead wire, whose collector is grounded, and whose base is connected to the failure display lead wire; a relay provided between the collector of the second transistor and ground; a switching means that normally closes a contact on the power supply lead wire side and closes a contact to which a failure indicator light is connected in response to driving of the relay; a grounding lead wire that grounds the base of the second transistor; a third resistor having a resistance value greater than the resistance value of the first resistor and the second resistor provided on the ground lead wire, and at least one of the power supply lead wire or the failure indication lead wire When the wire is disconnected, the second transistor is made conductive based on a change in bias to drive the relay, and the switching means is switched from the power supply lead wire side to the failure indicator light side to turn on the failure indicator light. 1. A fault indication circuit for a skid prevention device, characterized in that it is configured to