JPS60234045A - Brake lamp system trouble detecting device - Google Patents

Abstract

PURPOSE:To enable detection of a wide range of a trouble, such as fusing of a fuse, failure in operation of a brake switch, as well as disconnection of a brake lamp, by a method wherein a fuse, a brake switch, a relay coil, and a brake lamp are connected in series. CONSTITUTION:A fuse 2 for brake lamps 5(51-54), connected to the positive pole of a power source 1, is connected to a series circuit of a brake switch 3, relay coils 4(41-44) and a brake lamp 5. Further, the positive pole of the power source 1 is also connected to a trouble display part 11 through an ignition switch 10. An input A of trouble display part 11 is earthed through a series circuit of lead relay contacts 61-64 aditionally attached to the relay coils 41-44. Further, the input A is connected to the collector of a transistor TR through a diode D5, the emitter of the TR to the brake switch 3 and the relay coil 4, and the base to the contacts of the fuse 2 and the brake switch.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake light system failure detection device, and in particular detects a wide range of failures in the brake light system, such as disconnected wire harnesses, blown fuses, brake switch failures, and poor grounding of brake lamps. Relating to a detectable device.

2. Description of the Related Art Various failure detection devices have been known for detecting failures such as disconnections in various lighting equipment such as brake lights. For example, Japanese Patent Publication No. 52-41987 discloses a device that can detect a break in a lamp such as a brake lamp even when the lamp is not in use. In particular, such a failure detection device is desirable for brake lamps because they operate only when a rebrake is operated, which is different from that for headlamps and other lighting devices.

However, with conventional failure detection devices of this type, including the above-mentioned failure detection device, although it is possible to detect burnout of a lamp, brake light failure other than breakage of a brake lamp, such as burnout of a fuse or malfunction of a brake switch, The drawback was that system failures could not be detected.

In view of these shortcomings of the prior art, the main purpose of the present invention is to solve a wide range of brake light problems, including not only broken brake lights, but also broken fuses, wire harness breaks, poor grounding of brake lights, and broken brake switches. The object of the present invention is to provide a device capable of detecting system failures.

Such an object of the present invention is to provide a brake light system failure detection device, which comprises: a series circuit consisting of a fuse, a brake switch, a relay coil, and a brake lamp; a switching element that closes due to a potential difference between both ends of the brake switch; a relay contact that engages when all of the relay coils are energized; a display section that displays a failure state when both the switching element and the relay contact open; and a display section that responds to the brake switch; This is achieved by providing a brake light system failure detection device characterized by comprising an auxiliary switch capable of closing the switching element regardless of the potential difference between both ends of the brake switch.

Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings.

The accompanying drawing is a circuit diagram showing the entire brake light system failure detection device according to the present invention. The positive terminal of the power supply 1 is connected to a fuse for a brake lamp in a series circuit consisting of a brake switch 3, a relay coil 4, and a brake lamp 5.

In this embodiment, four brake lamps 51-54 are connected in parallel, and a relay coil 4-44 is connected in series for each brake lamp. Further, the positive terminal of the electric current lTi1 is also connected to a failure display section 11 via an ignition switch 10.

This fault indicator 11 is of a known type, and when the input A is at a low potential, that is, when the input is connected to ground, the built-in warning lamp 8 does not light up and the input A When the potential is high, that is, when the input A is disconnected from the ground, the warning lamp 8 lights up. It is preferable that this failure display section includes a delay circuit to prevent malfunctions and a self-holding circuit to reliably detect failures. The manual switch 9 is used to confirm that the fraud lamp 8 is not disconnected by grounding one end of the warning lamp 8.

The input A of the failure display section 11 is connected to the relay coils 41 to 41.
It is grounded through a series circuit of reed relay contacts 61 to 64 attached to 44. Therefore, the brake light 51
~54 are all lit, all relay coils 4~44
is energized, input A is kept at ground voltage, and if any one of the brake lamps is connected to the Ii line, the relay coil connected to that brake lamp is de-energized. , a reed relay contact attached to the relay coil opens, cutting off conduction between input A and ground.

In addition, the human power A is connected to the transistor TR via the diode D5.
is also connected to the collector. The emitter of the transistor is connected to the connection point between the brake switch 3 and the relay coil 4 via the diode D3, and the base of the transistor is connected to the Zener diode ZD and the diode D.
4 and a resistor R1 to a connection point between the fuse 2 and the brake switch 3. Also, the connection point between resistor R1 and diode D is connected to diode D1 and auxiliary switch 7.
is grounded through. This auxiliary switch 7 is designed to close when the brake switch 3 is pressed, and for the reason described later, after the brake switch 3 is closed, and under normal use. The auxiliary switch 7 is prevented from closing when the brake switch 3 is pressed.

Next, the operation of this brake light system failure detection device will be explained with respect to various different states of the brake light system.

(I) Normal operation (1) When both the brake switch 3 and the auxiliary switch 7 are open.

The positive terminal of power supply 1 is fuse 2, resistor R1, diode D4
The current flows from the base to the emitter of the transistor TR via the Zener diode ZD1, and is further grounded via the diode D3, relay coil 4 and lamp 5, so the transistor TR becomes conductive and the failure indicator 1
1 input A becomes low potential and the warning lamp 8 does not light up.

(2) Brake switch 3 is closed and auxiliary switch 7
is opened.

The current supplied from the positive terminal of the power supply 1 flows through the fuse 2, the brake switch 3, the relay coil 4, and the lamp 5 to the ground, so if all the brake lamps 51 to 54 are lit, all the relay coils 41 to 44 is energized, the reed relay contacts 61 to 64 are all closed, the input A of the failure indicator 11 becomes low potential, and the failure warning lamp 8 does not light up.

(3) When both the brake switch 3 and the auxiliary switch 7 are closed.

Since the auxiliary switch 7 is turned off, the transistor T
Since the base potential of R is low, the transistor TR is in a non-conducting state, but if the brake lights 51 to 54 are not disconnected, the reed relay contacts 6 to 64 are all closed, so the failure indicator 11 is The potential to the input becomes low, and the failure warning lamp 8 also does not light up.

(II) Operation in case of abnormality (1) Fuse blown.

If the fuse 2 is blown, the base current is not supplied to the transistor TR, the transistor TR becomes non-conductive, the brake lamp 5 is not turned on, and the reed relay contact 4 is heard, so the input A of the failure display section 11 is will make a high potential noise and the warning lamp 8 will light up.

(2) If the brake switch is malfunctioning and is always open.

Since the auxiliary switch 7 is closed when the brake pedal is operated, the current supplied from the positive terminal of the power supply 1 through the fuse 2 and the resistor R1 is grounded by the diode D1 and the auxiliary switch 7, so that the base of the transistor TR is No current is supplied, and transistor TR becomes non-conductive. Further, the brake lamp 5 is not lit, and the reed relay contact 6 is also open. Therefore, the input A of the failure display section 11 becomes a high potential, and the warning lamp 8 of the failure display section 11 lights up.

(3) In the case of brake light breakage.

In this case, one of the lamps is not lit, and one of the reed relay contacts 61 to 64 is opened. Moreover, since the brake switch 3 and the auxiliary switch 7 are closed when the brake pedal is operated, no base current is supplied to the transistor TR, and the transistor TR becomes non-conductive. Therefore, when operating the brake pedal,
The input A of the fault display section 11 becomes high potential, and the fault display section 1
1 warning lamp 8 lights up.

(4) In case of wire harness disconnection.

If there is a disconnection at the connection point B1 between the brake switch 3 and the relay coil 4, that is, at a part of the wire harness, the base current is no longer supplied to the transistor TR. In other words, 4 is the connection point among the paths that normally flow from the positive terminal of the power supply 1 to the base via the fuse 2, resistor R1, diode D4, and Zener diode ZD1, and from the emitter to the ground via the diode D3, relay coil 4, and lamp 5. Since B is cut off, transistor TR becomes non-conductive.

At this time, since the relay coil 4 is not energized, the reed relay contacts 61 to 64 are in a non-conducting state. Therefore, the input A of the fault display section 11 becomes a high potential, and the fault display section 11
The warning lamp 8 lights up.

(5) In case of ground failure.

If the grounding of the brake lamps becomes defective, at least one brake lamp will be disconnected from the ground, resulting in the same condition as the brake lamp disconnection described above, and the brake pedal will not be operated in the same way as above. When this occurs, the warning lamp 8 of the failure display section 11 lights up.

(6) If the auxiliary switch is malfunctioning and is always open,
As long as the brake switch 3 is open, the current supplied from the positive terminal of the voltage source $21 is supplied to the fuse, via the resistor R1, the diode D4 and the Zener diode ZD1, to the base of the transistor TR, and flows out from the emitter of said transistor. Since the current is grounded through the diode D3, the relay coil 4, and the lamp 5, the transistor TRIfi becomes conductive and the input A of the input display section 11 becomes a low potential, and the warning lamp 8 does not light up. brake pedal 3
When the brake lamp 5 lights up and the reed relay contacts 6 to 64 are closed, the failure indicator 1 is activated.
Since the potential of input 1 is low, the warning lamp 8 does not light up either.

Therefore, even if the auxiliary switch 7 fails, no particular inconvenience will occur, except that the failure of the brake switch 3 cannot be detected.

However, assuming a special case where the auxiliary switch 7 is closed before the brake switch 3 is engaged, the base current to be supplied to the transistor TR is transferred to the diode D1. Since the transistor TR is in a non-conducting state and the reed relay 6 is in a disconnected state, the input A of the fault display section 11 becomes a high potential, and there is no fault with the brake light. Despite this, there may be an inconvenience that the warning lamp 8 of the failure display section 11 lights up.

Therefore, it is necessary that the auxiliary switch 7 is closed only after the brake switch 3 is closed. This can also be achieved by mechanically interlocking the auxiliary switch 7 with the brake switch 3 so that it responds with a delay in response to the brake switch 3; however, if the brake switch 3 is a mechanical switch that is interlocked with the pedal, the auxiliary switch 7 Preferably, it comprises a pressure switch 7 responsive to the pressure in the brake hydraulic system. By doing this,
Not only can a desired delay characteristic be easily provided to the auxiliary switch 7, but by making the brake switch 3 and the auxiliary switch 7 completely separate switches, it is possible to prevent both switches from failing at the same time. can be made smaller.

As described above, according to the present invention, it is possible to detect not only a break in the brake light, but also failures in other parts of the brake light system, such as a blown fuse, a brake switch failure, a wire harness break, or a brake light ground failure. can do.

Although the present invention has been described above with reference to preferred embodiments, it goes without saying that the present invention can be practiced with various modifications based on the claims.

[Brief explanation of drawings]

The accompanying drawing is a circuit diagram showing an embodiment of a brake light system failure detection device according to the present invention. 1... Electric 1 2... Fuse 3... Brake switch 4... Relay coil 5...
・Brake light 6...Reed relay contact 7...
Auxiliary switch 8...Warning lamp 9...Reset switch 10...Ignition switch 11...Failure display section Patent applicant: Honda Motor Co., Ltd. Representative Patent attorney: Yo Oshima - Sat

Claims (2)

[Claims] (1) A brake light system failure detection device, which includes a series circuit consisting of a fuse, a brake switch, and a 1-roux coil brake lamp, a switching element that closes due to a potential difference between both ends of the brake switch, and all of the relay coils. a relay contact that closes when energized; a display section that displays a fault condition when both the switching element and the relay contact open; and a display section that responds to the brake switch and that displays a potential difference between both ends of the brake switch. A brake light system failure detection device comprising: an auxiliary switch capable of controlling the switching element regardless of the switching element. (2) The brake light system failure detection device according to claim 1, wherein the auxiliary switch is a pressure switch f'X activated by pressure within the brake hydraulic system.