JPH0736839Y2 - Trailer stop lamp disconnection detection circuit - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is used for an automobile towing a trailer.

〔Overview〕

The present invention is a trailer stop lamp disconnection detection circuit that detects a trailer stop lamp disconnection based on a change in the total current value flowing through the stop lamp.The current detected by the trailer stop lamp disconnection circuit is the control circuit current of the anti-skid brake device. In addition, the disconnection detection circuit and the control circuit of the stop lamp for the trailer are detected by detecting the disconnection at the current value between the total value of the currents and the current value of one stop lamp smaller than the total value. And coexist with to simplify the wiring equipment.

[Conventional technology]

Conventionally, a circuit for detecting the disconnection of a stop lamp for a trailer has a configuration shown in FIG. When the pickup switch PS _W that there is a connection of the trailer T is closed in the circuit of this motor vehicle M, disconnection detection relay 24
The open / close circuit 24B of the drive circuit operates, and the detection resistor 24A, which is the drive circuit, detects the change in the current value due to the disconnection of the stop lamp SL of the trailer T, and the indicator light provided in the driver's seat.
A broken wire is displayed on IL. In this case, the detection resistor 24A has a stop lamp switch linked to the brake pedal 21.
The output current of the stop lamp relay 23 activated by 22 is supplied. In this conventional example, the input circuit of the control circuit of the anti-skid brake device (ABS) for the trailer was a separate system.

FIG. 4 shows a conventional example in which the wiring of the automobile is simplified by coexisting the circuit of the stop lamp SL of the trailer T with the circuit of the input system of the control circuit of the anti-skid brake device.

In this conventional example, the control circuit 36 of the anti-skid brake device requires a control current regardless of whether or not the brake pedal 31 is operated. For this reason the stop lamp relay
The control circuit 36 is connected to the two switching contacts a and b, and the stop lamp SL of the trailer T is connected via the electric coupler 35 to the contact b which is switched when the brake pedal 31 is operated. It was

In this conventional example, the stop lamp for the trailer and the control circuit coexist.

[Problems to be solved by the device]

However, the conventional example shown in FIG. 4 cannot detect the disconnection of the stop lamp for the trailer. In order to do this, there is the drawback that a circuit containing a separate relay is required.

Further, it is necessary that the power supply voltage (for example, DC24V) of the automobile is always applied to the control circuit via the contact that is switched by the brake operation.

The present invention solves these problems and, by coexisting with the control circuit of the anti-skid brake device, provides a trailer stop lamp disconnection detection circuit that simplifies wiring rigging and reduces manufacturing costs. The purpose is to provide.

[Means for Solving the Problems]

The present invention is a stop lamp relay for controlling the blinking of a stop lamp for a trailer that is energized and released by an open / close switch interlocking with a brake pedal, and a disconnection detection relay in which a drive circuit is inserted in series with the contact of the stop lamp relay. And a disconnection detection circuit for a trailer stop lamp, which includes a pickup switch and a disconnection indicator lamp that are connected in series to the open / close circuit of this disconnection detection relay and are closed when there is a trailer connection. The contact of is a switching type, the drive circuit of the disconnection detection relay is connected to its common contact, the control circuit of the trailer anti-skid brake device is connected to the two switching contacts, and these two switching contacts Among them, the stop lamp for the trailer is turned to the side connected to the common contact when the brake is operated. The critical point of operation of the relay for disconnection detection is the sum of the current value of the control circuit and the current value when all the stop lamps for the trailer are in a normal state, the current value of the control circuit and this trailer It is characterized in that it is set between one of the stop lamps and the total value of the broken states.

[Action]

The contact of the stop lamp relay is a switching type,
Since the control circuit of the skid / brake device is connected to the two switching contacts, control power is supplied to the control circuit via the contacts corresponding to the brake operation.

Since the common contact of the stop lamp relay is connected to the drive circuit of the disconnection detection relay of the trailer stop lamp, when the lamp current of the stop lamp flows through this drive circuit, the control current of the control circuit also flows at the same time. Therefore, the setting of the operation critical point of the drive circuit can be performed by adding the control current to the lamp current to detect the presence or absence of the disconnection of the stop lamp.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of the present invention. In the figure, a vehicle M pulls a trailer T, and a stop lamp relay 3 for controlling blinking of four stop lamps SL of a trailer T which is energized and released by a stop lamp switch 2 which interlocks with a brake pedal 1. , A disconnection detection relay 4 in which a detection resistor 4A, which is a drive circuit, is inserted in series with a contact of the stop lamp relay 3, and a trailer T connected in series to an open / close circuit 4B of the disconnection detection relay 4.
Pickup switch PS _W closed when there is a connection of
And the stop lamp SL is provided with an indicator light IL provided in the driver's seat for displaying a disconnection. Further, reference numerals 5 and 6 are an electric coupler and an anti-skid, respectively.
This is the control circuit for the braking device (ABS).

Here, the feature of the present invention is that the contact of the stop lamp relay 3 is a switching type having two switching contacts a and b, and the common contact c is the drive circuit of the disconnection detecting relay 4 A resistor 4A is connected, a control circuit 6 is connected to the switching contacts a and b, and a switching contact b connected to a common contact c when the brake pedal 1 is operated is connected to a trailer T via an electric coupler 5. 4 stop lamps SL are connected, and the operation critical point of the disconnection detection relay 4 is the control circuit 6
And the sum of the current values in which all of the four stop lamps SL are in a normal state (the value of I ₄ shown in FIG. 2),
It is a value (also I ₀ ) set between the current value of the control circuit 6 and the sum of the current values when one of the stop lamps SL is disconnected (also I ₃ ).

FIG. 2 is an explanatory view of the operation critical point of the disconnection detecting relay 4. In this figure, the vertical axis represents the value of the current flowing through the detection resistor 4A, which is the drive circuit of the disconnection detection relay 4, and the horizontal axis represents the respective conditions. The current value when there is no trailer T is only the control current I _C of the control circuit 6. In a normal state where there is a trailer T and there are no breaks in the four stop lamps SL, the current value is the combined value I ₄ of the control current I _C and the current values of the _four stop lamps SL, and one stop lamp SL is If the wire is broken, the total value will be I ₃ . Operating critical point I ₀
Is defined between the current values I ₄ and I ₃ .

In the present embodiment, the above-mentioned operating critical point is set by adjusting the tap of the detection resistor 4A as a drive circuit.

In the present embodiment, as described above, the line of the anti-skid brake device system and the line of the trailer stop lamp disconnection detection system can coexist with a simple configuration. That is, the number of relays can be reduced as compared with a case where the control circuit of the anti-skid brake device and the stop lamp current detection circuit are separate systems.

[Effect of device]

As described above, according to the present invention, the disconnection detection circuit for the trailer stop lamp can coexist with the control circuit of the anti-skid brake device and its line system, so that the circuit is simplified and the wiring fitting is simplified. It has the effect of reducing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention. FIG. 2 is an explanatory view of the operation limit points of the relay of the embodiment. FIG. 3 is a circuit diagram of a conventional example (1). FIG. 4 is a circuit diagram of a conventional example (2). 1, 21, 31 ... Brake pedal, 2, 22, 32 ... Stop lamp switch, 3, 23, 33 ... Stop lamp relay, 4, 24 ... Disconnection detection relay, 4A, 24A ... with drive circuit A detection resistor, 4B, 24B ... Switching circuit, 5, 25, 3
5 ... Electric coupler, 6,36 ... Control circuit of anti-skid brake device, a, b, c ... Various terminals, IL ...
... Indicator, M, T ... Car, trailer, PS _W ... Pickup switch, SL ... Trailer stop lamp.

Claims (1)

[Scope of utility model registration request] 1. A stop lamp relay for controlling the blinking of a stop lamp for a trailer which is energized and released by an opening / closing switch interlocking with a brake pedal, and a disconnection detection circuit in which a drive circuit is inserted in series with a contact of the stop lamp relay. In the disconnection detection circuit for a trailer stop lamp, which includes a relay, a pickup switch and a disconnection indicator lamp which are connected in series with the disconnection detection relay switching circuit and are closed when the trailer is connected, The contact of the lamp relay is a switching type, the drive circuit of the disconnection detection relay is connected to the common contact, and the two switching contacts are anti-skid for trailer.
A control circuit of the brake device is connected, and a stop lamp circuit for a trailer is connected to a side of the two switching contacts that is connected to the common contact in a state where the brake is operated, and the operation criticality of the disconnection detection relay. The point is that the sum of the current values of the control circuit and the stop lamp for the trailer is normal, and the current value of the control circuit and one of the stop lamps for the trailer are disconnected. A trailer stop lamp disconnection detection circuit characterized by being set between the sum of current values.