JPS604441A - Head lamp circuit - Google Patents

Abstract

PURPOSE:To improve safety, by so constitution the titled circuit that it is enabled to light a head lamp by operation of a manual switch at the time of a trouble of a relay for the head lamp, in a head lamp circuit having a control circuit for lighting and putting out lights making the head lamp light automatically according to light and dark surroundings. CONSTITUTION:When surroundings become slightly dark bacause of evening at the time of turning a mode into an automatic one by turning an automatic switch S4 of a lighting switch S3 ON, a small lamp lighting signal is put out from a control circuit 2' for lighting and putting out lights based on an output from a light sensor 1 according to brightness at that time, a relay 8 is energized and a small lamp 5 is lit. In addition to the above, when a lighting signal of a head lamp is put out by becoming the surroundings dark further, relays 15, 17 are energized and the head lamps 3, 4 are lit. On the one hand, when manual head lamp switches S5, S6 are connected with a main side contact point M, the head lamps 3, 4 are lit similary.

Description

[Detailed description of the invention] (b) Technical field The present invention relates to a headlamp circuit.

(Prior Art) Some recent vehicles are designed to automatically turn on and off the headlamps according to the surrounding brightness, in addition to manual operation of the light switch. Figure 1 shows this type of conventional vehicle. An example of a headlamp circuit is shown below.
2 is a light sensor such as a phototransistor that detects the surrounding brightness and outputs a voltage according to the brightness, 2 is a left and right headlamp 3 based on the output from the light sensor 1.
, 4 and small lamps (tail lamps, clearance lamps, etc.) 5;
6 is a headlamp relay for lighting the headlamps 3 and 4; 7 is a switching relay whose contacts are normally connected to the main side; and 8 is a small lamp relay for lighting the small lamp 5.

SWl is a manually operated lighting switch, and this lighting switch SW engineer includes a small lamp switch S1, a headlamp switch S2,
It consists of a dimmer switch S3 for switching the switching relay 7 from the main side to the dimmer side, and an auto switch S4 for turning on the headlamp 3.4 and the small lamp 5 in automatic mode. SW2 is the ignition switch, SD is the door switch that turns on when the driver's side door is opened, and the ignition switch SW2
When the door is opened while the head lamp 3.4 and the small lamp 5 are turned off, the operation of the on/off control circuit 2 for the head lamp 3.4 and the small lamp 5 is stopped. L13 without 9 is a fuse, and 14 is a battery.

In the above headlamp circuit, if you turn on the auto switch S4 of the lighting switch SW1 and set it to automatic mode, when the surroundings become slightly dark (such as at dusk), the light sensor will be activated according to the brightness at that time. 1
A small lamp lighting signal is output from the lighting/extinguishing control circuit 2 based on the output from the small lamp relay 8, and as a result, the small lamp relay 8 is energized and the small lamp 5 is turned on. After that, when the surroundings become even darker (such as at night or when driving in a tunnel), the light on/off control circuit 2 outputs a small lamp lighting signal based on the output from the light sensor 1 according to the brightness at that time. In addition, the headlamp lighting signal is output and the headlamp relay 6 is energized, so the dimmer switch S3 is generally in the on state, so the headlamp 3.4 low beam filament DL is turned on.
, DR emits light. Also, in this case, the dimmer switch S
3 is turned off, the switching relay 7 is switched from the dimmer side to the main side, and the traveling beam filaments ML and MR of the headlamp 3.4 now emit light. In this way, in the automatic mode, turning on and off of the headlamp 3.4 and the small lamp 5 can be automatically controlled according to the surrounding brightness.

On the other hand, when the auto switch S4 of the lighting switch SW1 is turned off, when the small lamp switch S1 is manually turned on, the small lamp relay 8 is energized, so that the small lamp 5 is lit. Furthermore, when the headlamp switch S2 is turned on, the headlamp relay 6 is energized, and since the dimmer switch S3 is generally on, the headlamp 3.
The passing beam filaments DL and DR of 4 emit light. At this time, when the dimmer switch S3 is turned off, it is set to 3- as in the automatic mode, and the switching relay 7 is switched from the dimmer side to the main side, so that the running beam filaments I-MI, , MR of the headlamp 3.4 emit light.

In this way, in the manual mode, the headlamp 3.4 and the small lamp 5 can be turned on and off by operating the lighting switch SW and the small lamp S headlamp switch S2.

By the way, in such a circuit configuration, if the headlamp relay 8 at night breaks down, or if an abnormality such as a disconnection occurs in the path connected to the headlamp relay 8, both automatic mode and manual mode will be activated. In this mode, power to the left and right headlamps 3.4 is cut off, causing both headlamps 3.4 to go out, which may impede driving.

(c) Object and Structure of the Invention The present invention has been made in view of the above points, and improves the reliability of the headlamp circuit and improves the reliability of the headlamp circuit in dark places. For the purpose of safe driving, -5-4- for this purpose, a manual switch connected to each headlamp, a light on/off control circuit that outputs a signal depending on the surrounding brightness, and the light on/off control circuit are provided. The headlamp circuit is configured with a relay connected in parallel to the manual switch, which turns on the headlamp in response to a signal from the manual switch.

) Example The present invention will be explained below based on the drawings.

FIG. 2 shows an embodiment of a headlamp circuit according to the invention, in which the same reference numerals as in FIG. 1 indicate the same components. In this embodiment, a relay for turning on the left and right headlamps in automatic mode and a switch for turning them on in manual mode are provided for each headlamp independently. Specifically, the left headlamp 3 Contact 15a of headlamp relay 15 for lighting
is connected in series with the main dimmer switching relay 16, and the coil 15b of the relay 15 is connected to the light on/off control circuit 2'.
connected to the output side of the On the other hand, contact 1 of the headlamp relay 17 for lighting the right headlamp 4-
7a is connected in series with the main and dimmer switching relay 18, and the coil 17b of the relay 17 is connected to the output side of the lighting/extinguishing control circuit 2'. Each coil 16a, 18a of the main and dimmer switching relay 16.18 is connected to a dimmer switch S3, and each relay]6
．． 18 are normally connected to the main side.

Lighting switch SW3 85 and S6 are interlocking headlamp switches for turning on the left and right headlamps 3.4 by manual operation, and are designed to switch between the main side contact M and the dimmer side contact. There is.

In the above headlamp circuit, if you turn on the auto switch S4 of the lighting switch SW3 and set it to automatic mode, when the surroundings become slightly dark (such as at dusk), the light will change depending on the brightness at that time. Sensor I
A small lamp lighting signal is outputted from the lighting/extinguishing control circuit 2' based on the output from the small lamp relay 8, and as a result, the small lamp relay 8 is energized and the small lamp 5 is turned on. After that, when the surroundings become even darker (at night or when driving in a tunnel), the light on/off control circuit 2' sends a small lamp lighting signal and other signals based on the output of the light sensor l according to the brightness at that time. A headlamp lighting signal is also output, and headlamp relays 15 and 17 are energized. Furthermore, since the dimmer switch S3 is normally turned on, the filament DL for the passing beam of the headlamp 3 emits light via the main/dimmer switching relay 16, and the passing beam of the headlamp 4 is emitted via the main/dimmer switching relay 18. Filamen for beam)D
R emits light. In addition, in this case, when the dimmer switch S3 is turned off, the main and dimmer switching relays 16.18 are switched from the dimmer side to the main side, so this time the running beam filament ML of the headlamp 3.4
, MR emits light. In this way, in the automatic mode, the turning on and off of the headlamps 3.4 and 7-small lamps 5 can be automatically controlled depending on the surrounding brightness.

On the other hand, when the auto switch S4 of the lighting switch SW3 is turned off and manual operation is performed, when the small lamp switch S is turned on, the small lamp relay 8 is energized and the small lamp 5 is turned on.

Further, when the headlamp switches S5 and S6 are connected to the main side contact M, the traveling beam filaments ML and MR of the headlamp 3.4 emit light. On the contrary,
When the headlamp switches S5 and S6 are connected to one side contact of the headlamp switch, the passing beam filament DL1DR of the headlamp 3.4 emits light. In this way, in the manual mode, the small lamp switch Sl of the lighting switch SW3 and the headlamp switch S5
, S6, the headlamp 3.4 and small lamp 5 can be turned on and off.

In this way, even if one of the headlamp relays 15.17 fails in automatic mode (it is rare for both headlamp relays to fail at the same time), the other one will fail. Since the headlamp relay operates, both the left and right headlamps 3.4 will not go out. Also, in manual mode, the headlamp 3.4 is connected to the headlamp relay 15 and 7, respectively. In this case, the headlamp 3.4 can be turned on even if both the headlamp relays 15 and 17 fail.

In this embodiment, a so-called two-lamp type headlamp circuit having two headlamps is illustrated, but the present invention can also be applied to a so-called four-lamp type headlamp circuit having four headlamps.

(e) Detailed Description of the Invention As described in detail, the present invention has the effect that even if the headlamp relay fails, the headlamp can be turned on by using a manual switch, allowing safe driving in a dark place. .

10-

[Brief explanation of drawings]

FIG. 11 shows an example of a conventional headlamp circuit, and FIG. 2 shows an embodiment of the headlamp circuit according to the present invention. 2... Light on/off control circuit S S... Headlamp switch (manual switch)
5, 6 15.17...Headlamp relay (relay) Patent applicant: Nissan Motor Co., Ltd. Attorney Hiroo Tsuchi Suzuki 11-

Claims (1)

[Claims] A manual switch connected to each headlamp, a light-on/off control circuit that outputs a signal depending on the surrounding brightness, and a relay that turns on the headlamp in response to the signal from the light-on/off control circuit and is connected in parallel with the manual switch. A headlamp circuit characterized by comprising: