JPS62244733A - Burnout compensator for vehicle lamp - Google Patents

Abstract

PURPOSE:To miniaturize a power switch part, by reducing the switch part where a lamp load current is flowing. CONSTITUTION:When there is no burnout trouble, a first OR device 14 and an oscillating device 15 both have a low beam lamp 2 or a high beam lamp 3 lighted by a duty ratio voltage of 100 percentage as in a command of a lamp operating switch 17. On the other hand, in the case where the burnout trouble occurs, such a signal that lights a lamp at the side being not disconnected is outputted to the first OR device 14 and a second OR device 16 respectively. And that, when the low beam lamp 2 is burnt out at a time when the lamp operating switch 17 has commanded the low beam side, the second OR device 16 has the high beam lamp 3 sensitively lighted by a signal out of the oscillating device 15.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a headlight for a vehicle that is equipped with a low beam lamp and a high beam lamp, and when a lamp disconnection failure occurs, The present invention relates to a disconnection guarantee device for a vehicle lamp that switches to a lamp that is not disconnected so that the lamp continues to be lit.

[Conventional technology]

Conventionally known examples include Utility Model Publication No. 56-23151 and Utility Model Publication No. 57-23226.

To explain these two examples schematically, first, in FIG. 3, when the lighting of the high beam lamp 3 or the low beam lamp 2 is switched by the dimmer switch 100 and a disconnection is detected by the lamp current detection means 7, two sets of Current is supplied from the switch means 101 side to the low beam lamp 2 and the high beam lamp 3. A circuit 1 detects whether the dimmer switch 100 selects the low side or the high side.
02 is present and the switch 100 detects the low side, when the low side lamp 2 is disconnected, the current flowing through the high beam lamp 3 is controlled intermittently by the switch means 101 according to a command from the oscillator 103. It is something.

However, in the circuit of FIG. 3, in addition to the manually operated dimmer switch 100, a switch means 101 for controlling the lamp current is required, and since the lamp flows through both the dimmer switch 100 and the switch means 101, the dimmer Since the current capacity of the contacts of the switch 100 must be increased, and the lamp current must flow through both the dimmer switch and the switch means 101, the voltage drop from the power source to the lamp 2.3 increases. .

Also, the wiring is complicated.

Next, in the known example shown in FIG. 4, a dimmer switch 100a,
This uses an interlocking switch like 100b. This circuit requires a special interlocking switch, and the switch circuit that controls the lamp current is complicated.
This is similar to the diagram, and since the lamp current must flow through the dimmer switch, there is a problem that the voltage drop from the power supply to the lamp is large.

[Problem that the invention seeks to solve]

In order to reduce the voltage drop from the power source to the lamp, the present invention does not require a manually operated operation switch between the power source and the lamp, and is configured so that the power source and the lamp can be connected with as short a wiring as possible. It is an object of the present invention to provide a disconnection protection device for a vehicle lamp which can simplify the configuration by reducing the number of switch means through which lamp load current flows, and downsize the power switch portion.

[Summary of the invention]

The outline of the present invention will be explained using the schematic diagram of FIG. In order to shorten the wiring from the positive probe B of the battery that constitutes the on-board power source to the low beam lamp 2 and high beam lamp 3, a first wire is installed between the on-board power source and each lamp 2, 3.
Only the switch device 5 and the second switch means 6 are interposed. As a result, there are two sets of power switches, one for low beam and one for high beam, which reduces the number of switch means and simplifies the configuration, making it small and inexpensive. 8 is a control circuit, and this control circuit 8
A first switch means 5 and a second switch means 6 are connected to the control circuit 8, and a lamp operation switch 17 is connected to the control circuit 8. It issues a low-high switching command that instructs either to turn on the beam or to turn on the high beam lamp.

Next, the control circuit 8 has the following configuration. First, a LAND means 9 is provided, which outputs a low illuminance lighting signal when the lamp operation switch 17 instructs the lighting of the low beam lamp 2 and also instructs the lighting of the headlights.

Next, a second AND means 10 is provided, which outputs a high-intensity lighting signal when the lamp operation switch 17 instructs the lighting of the high beam lamp 3 and also instructs the lighting of the headlights.

Next, the disconnection detection means 11 determines whether the lamp load current is below a predetermined value based on a signal from the lamp current detection means that detects the lamp load current, and issues a disconnection signal when the lamp load current is below the predetermined value. is provided.

Next, a third AND means 12 is provided, which detects the disconnection of the low beam lamp 2 and outputs a high side switching signal.

Next, a fourth AND means 13 is provided, which detects disconnection of the high beam lamp 3 and outputs a low side switching signal.

Next, a first OR means 14 is provided, which performs an OR operation on the low side switching signal and the low illuminance lighting signal, and makes the first switch means 5 conductive continuously to turn on the low beam lamp 2.

Next, an oscillation means 15 for outputting an intermittent signal at a predetermined duty ratio is provided, and a second OR means 16 is also provided. This second OR means 16 intermittently controls the second switch means 6 by the signal of the oscillation means 15 when the high side switching signal is output, and when the high illuminance lighting signal is output, the second
Switch means 6 is turned on.

[Effect]

In the present invention, a manually operated lamp operation switch 17 is not provided between the power source and the lamp 2.3;
Instead of this, the first switch means 5 and the second switch means 6
will be established. These switch means are controlled by a first OR means 14 and a second OR means 16. When there is no disconnection failure, the first OR means 14 and the oscillation means 15 turn on the low beam lamp 2 or the high beam lamp 3 with a duty ratio voltage of 100% as instructed by the lamp operation switch 17. On the other hand, when a disconnection failure occurs, the third AND means 12 and the fourth AND means 13 output a signal for lighting the lamp that is not disconnected, that is, a low side switching signal and a high side switching signal, to the first OR means 14. and is output to the second OR means 16. Moreover, when the low beam lamp 2 is disconnected while the lamp operation switch 17 is commanding the low beam side, the second OR means 16 turns on the high beam lamp 3 in a dimmed manner based on the signal from the oscillating means 15.

That is, the present invention provides the first OR means 14 and the second OR means 16 at the output stage of the control circuit 8, so that when a disconnection fault occurs,
By outputting a signal suitable for the situation to each switch means 5 and 6 depending on when a disconnection failure does not occur,
The first switch means 5 and the second switch means 6 are configured to light the lamp at a duty ratio of 100% in a state where there is no lamp breakage fault, and also control dimmed lighting when a lamp breakage fault occurs. This is what I did. As a result, unlike the conventional figures 3 and 4, the path through which the lamp load current flows does not change between when the lamp is normal and when the lamp is disconnected (therefore, the number of power switches through which the lamp load current flows is reduced). In addition, by interposing the control circuit 8 between the lamp operation switch 17 and the lamp current detection means 7, the first switch means 5, and the second switch means 6, the lamp load can be reduced. The current is made to flow to the lamps 2 and 3 without passing through the lamp operation switch 17.

〔Effect of the invention〕

As described above, in the present invention, the number of power switch means may be two sets, one for low beam and one for high beam, and
The lamp load current only needs to flow through these two sets of switch means and does not need to go through the lamp operation switch located in front of the vehicle driver, so the wiring is shortened and power loss due to voltage drop is reduced. Can be reduced. In addition, reducing the number of power switches contributes to miniaturization,
And it can be constructed at low cost.

〔Example〕

An embodiment of the apparatus of the present invention will be described below based on the drawings.

In FIG. 1, 2 is a low beam lamp, and 3 is a high beam lamp. The low beam lamp 2 and the high beam lamp 3 form a headlamp. Reference numeral 4 represents a battery serving as an on-vehicle power supply, and 5 represents a first switch means, which uses a field drop transistor. 6 is a second switch means.

7a and 7b are wiring parts for configuring the lamp current detection means, which connect the first switch means 5 and the second switch means 6.
This is to detect the voltage drop between both ends.

8 is a control circuit, and in this first embodiment, OR
Although it is constructed using circuits, AND circuits, etc., it can also be constructed using a 1-bit microcomputer.

9 is a first AND means, 10 is a second AND means, and A
It is composed of an ND circuit, and an inverter 23 is connected to the input side of the ND circuit.
, 24, 25, and 26 are provided. lla, llb
1 is a comparator constituting a disconnection detection means, and the positive terminal on the input side is connected to connecting portions 7a and 7b, respectively, and the negative terminal is connected to a comparison voltage V REF.

13 is a fourth AND means, and 14 is a first OR means. Further, 12 is a third AND means, 15 is an oscillation means, and 27 is an A
It is an ND circuit. 16 is a second OR means;
The OR means 16 and the first OR means 14 are connected via resistors 28, 29 to transistors 32, 33 forming a buffer circuit, respectively. Further, the transistor 32 has P
The gate of the field drop transistor 5 of the channel is connected, and the gate of the field drop transistor 6 is connected to the transistor 33. Reference numeral 17 denotes a lamp operation switch, which is provided near the steering wheel in the driver's seat of the vehicle. Three wires are connected from this lamp operation switch 17 to a control circuit 8. 20 to 22 are resistors. Further, 30.31 and 34.35 are resistances of the buffer circuit.

[Operation explanation]

The operation of the above embodiment will be explained below.

The lamp operation switch 17 has three switch operation positions: an off position, a tail position, and a head position, and has terminal positions labeled tail, head, and E.

Further, as another operation switch mechanism of the lamp operation switch 17, there is a dimer switch part 17a, which includes the L
O% H1, three operating positions for passing and Lo,
It has a terminal for H11 head E. The table in FIG. 1 shows that even if the halide control switch portion 17b is operated to the head position, the terminal tail, head, and E are grounded.

Now, if you operate the light control switch to the head position, the terminal head will be grounded, so the inverter 2
A low signal is input at 4.25.

Therefore, the Hi-multiple signal is input to the AND circuits 9 and 10. When the dimmer switch 17a selects the LO position, the terminal Lo is grounded, so a Lo times signal is input to the inverter 23, and an H signal is output from the AND circuit 9. This Hi double signal low illuminance lighting signal is configured and is output when the lamp operation switch instructs the lighting of the low beam lamp and also instructs the lighting of the headlights. And this output is the first O
The signal is input to the R means 14. Therefore, the transistor 32
is ONL, the first switch means 5 is turned on, and the low beam lamp 2 is turned on.

Next, a case will be described in which the lamp operation switch 17 issues a command to turn on the high beam.

When the light control switch 17b is in the forward/node position and the dimmer switch 17a is in the Hi position, a low signal is applied to the inverter 25, and a low signal is also applied to the inverter 26. Therefore, 2nd A
The AND circuit 10 forming the ND means 10 outputs a Hi signal. This Hi signal constitutes a high illuminance lighting signal, and this signal is used by the second OR means 16 and the fourth AND means 1.
3 and given. Therefore, the transistor 31 is turned ON by the H1 output of the second OR means 16, and the second switch means 6 is also turned ON. As a result, the high beam lamp 3 is turned on, and high beam illumination is performed. Next, a case where a disconnection fault occurs will be explained. This disconnection failure occurs in the lamp filament, and in order to detect this, the current detection means in this embodiment uses the voltage drop that occurs across the field drop transistor. There is. However, the present invention is not limited to the use of field effect transistors; therefore, the lamp current detection means may be constructed by other means using low resistance.

If the filament of the low beam lamp 2 is broken while the low beam lamp 2 is currently lit, the voltage drop across the first switch means 5 becomes small and the connection point 7
The potential of a becomes higher. Therefore, the voltage at the positive terminal of the comparator 11b connected to the connection point 7a is the comparison voltage V RE
P, and a Hi signal is sent from the comparator 11b to the third AN.
It is output to the D means 12. The third AND means 12 includes the L-th
Since the low illuminance lighting signal from the AND means 9 is input, a Hi signal is output from the third AND means 12, and this H signal is output from the third AND means 12.
The 4 signals constitute a Hi side switching signal. That is, 3rd A
The ND means 12 ANDs the low illuminance lighting signal and the disconnection signal output from the comparator 11b, and outputs the low beam lamp 2.
Detects the disconnection of the wire and outputs a Hi side switching signal. and,
Based on this signal, the AND circuit 27 takes in the oscillation output of the oscillation means 15 and outputs an intermittent signal to the second OR means 16.

As a result, the second OR means 16 turns on and off the transistor 33 at a predetermined duty ratio. Therefore, the second switch means 6 is also turned on and off, and the high beam lamp 3 is turned on in a dimmed manner at a predetermined illuminance. Therefore, when the low beam lamp 2 has a disconnection failure, the high beam lamp 3 is dimmed and turned on to detect this.

Next, a case will be described in which a disconnection failure occurs while the high beam lamp 3 is turned on. In this case, connection point 7b
The potential of comparator 1 connected to connection point 7b rises.
The potential of the positive terminal of 1a becomes high. Therefore, the Hi-multiple signal is input from the comparator 11a to the AND circuit constituting the fourth AND means 13. Also, at this time, since the high illuminance lighting signal from the second AND means 10 is input to the fourth AND means 13, a Hi times signal is output from the fourth AND means 13, and this signal is sent to the transistor 32 via the OR circuit 14. As a result, the first switch means 5 is turned on continuously, and the low beam lamp 2 is turned on with a duty of 100%. That is, when the high beam lamp 3 causes a disconnection failure, the low beam lamp 2 is turned on to ensure this, and at this time, almost the full voltage of the on-board power supply 4 is applied to both ends of the low beam lamp 2. .

In the embodiments described above, the voltage drop of the field effect transistor is used as the current detection means, but if a normal transistor or relay is used as the first switch means 5 and the second switch means 6, the current detection It is also possible to use a means known to have low resistance. Further, in this case, it is also possible to configure only one comparing means which constitutes the disconnection detecting means. When the lamp load current of either lamp 2 or 3 becomes abnormally low, this one disconnection detection means gives a signal to the third AND means 12 and the fourth AND means 13, and the third
The AND means 12 and the fourth AND means 13 may determine whether the disconnection is on the low beam lamp 2 side or the high beam lamp 3 side.

Furthermore, although the control circuit 8 has been explained using a logic circuit,
This can be configured with computer software. Further, the control circuit 8 may be provided near the instrument panel of the vehicle, and the first switch means 5 and the second switch means 6 may be incorporated into the control circuit 8 and installed near the instrument panel, but the low beam lamp 2, It may be provided in a portion adjacent to the high beam lamp 3, that is, in the engine room. In this case, when the voltage of the battery 4 is near the lamp 2.3, the lamp 2.3 is connected via the first switch means 5 and the second switch means 6 with an extremely small voltage drop.
Can supply current to 3. Also, if the first switch means 5
Even when the second switch means 6 is installed in the instrument panel, the voltage drop is reduced compared to the conventional system in which current flows to the low beam lamp 2 and the high beam lamp 3 via a lamp operation switch near the steering wheel. can be done.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram constituting an embodiment of the device of the present invention;
FIG. 2 is a schematic diagram explaining the outline of FIG. 1, and FIGS. 3 and 4 are schematic diagrams showing the configuration of a conventional device. 2...Low beam lamp, 3...High beam lamp, 5... 1st
Switch means, 6... Second switch means, 17...
Lamp operation switch, 7...Lamp current detection means, 8
. . . control circuit, 9 . . . first AND means. 10... Second AND means, 11... Disconnection detection means,
12... Third AND means, 13... Fourth AND means, 14... First OR means, 15... Oscillation means, 16
...Second OR means.

Claims (1)

[Scope of Claims] A low beam lamp and a high beam lamp constituting a headlamp of a vehicle, a first switch means for connecting the on-vehicle power source to the low beam lamp, and a second switch means for connecting the on-vehicle power source to the high beam lamp.
a switch means, a lamp operation switch that issues a command to turn on the headlight and a low-high switching command that instructs either the low beam lamp or the high beam lamp to be turned on; a lamp flowing to the headlamp; comprising a lamp current detection means for detecting a load current, and a control circuit connected to the lamp operation switch and the lamp current detection means to control ON and OFF states of the first switch means and the second switch means, The control circuit includes a first AND means for generating a low-intensity lighting signal when the lamp operation switch instructs to turn on the low beam lamp and instructs to turn on the headlight; and a second AND means for issuing a high-intensity lighting signal when a command is given to turn on the headlights, and a second AND means connected to the lamp current detection means for detecting that the lamp load current is below a predetermined value. a disconnection detection means that outputs a disconnection signal; and a third AN that performs an AND operation of the disconnection signal and the low illuminance lighting signal to detect disconnection of the low beam lamp and output a high side switching signal.
D means, an AN of the disconnection signal and the high illuminance lighting signal;
a fourth AND means for detecting a disconnection of the high beam lamp and outputting a low-side switching signal; and a first OR means for ORing the low-side switching signal and the low-illuminance lighting signal to turn on the first switch means. and oscillation means for outputting an intermittent signal at a predetermined duty ratio, and when the high side switching signal is output, the second switch means is controlled intermittently by the signal of the oscillation means, and when the high illuminance lighting signal is output. and a second OR means for turning on the second switch means.