JPH03256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a headlamp device used in a vehicle such as a train.

[Technical background of the invention and its problems]

Conventionally, this type of headlight device uses two lights: a passing beam lamp and a running beam lamp.
Both lamps were switched on and off. Furthermore, these two lamps were generally incandescent bulbs or halogen bulbs. However,
In recent years, from the viewpoint of energy conservation, research has been conducted into using discharge lamps with high light conversion efficiency in this headlamp device. In this case, two discharge lamps are considered for two types of illumination: a running beam and a passing beam. However, when a discharge lamp is used in a headlight device, unlike conventional light bulbs, the discharge lamp and the lighting device including the circuit for lighting the discharge lamp are bulky and heavy, and it is not economical. There were flaws.

[Purpose of the invention]

The present invention has been made to eliminate these drawbacks, and an object of the present invention is to provide a headlamp device that can be made smaller and lighter and moreover, can improve economical efficiency.

[Summary of the invention]

This invention applies a magnetic field in a substantially perpendicular direction to the arc of a high-pressure discharge lamp that is held horizontally at approximately the focal point of a reflecting mirror and is lit with direct current, and switches between a traveling beam and a passing beam by switching the direction of the arc current. This is how it was done.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in Figure 1, connect the DC lighting device 2 to the DC power supply 1, and connect the output terminal of the DC lighting device 2 to the
A series circuit of NPN type first and second transistors 3 and 4 and a series circuit of NPN type third and fourth transistors 5 and 6 are connected, respectively. A high pressure discharge lamp 7 such as a metal halide lamp is connected between the connection point between the first and second transistors 3 and 4 and the connection point between the third and fourth transistors 5 and 6. Further, the above-mentioned coil 9 of magnetic field applying means, which is formed by winding a coil 9 around an E-shaped core 8, is connected to the above-mentioned DC power supply 1. As shown in FIG. 2, the high pressure discharge lamp 7 has an inner tube 7c in which electrodes 7a and 7b are arranged facing each other, and an outer tube 7d surrounding the inner tube 7c. As shown in FIGS. 3 and 4, the high-pressure discharge lamp 7 has a reflective mirror case 10 that is substantially a paraboloid of revolution.
The focal point is held approximately horizontally within the focal position. The front opening of the reflective mirror case 10 is closed with a specially processed front glass 11. The magnetic field applying means is arranged to apply a magnetic field approximately perpendicularly to the arc of the high pressure discharge lamp 7 and in the water direction, as shown by the solid arrow "H" in FIG. 2, by energizing the coil 9. ing.

Further, the first switch of the changeover switch 12 is connected to the DC power supply 1.
A series circuit of the light emitting diode 14D of the first photocoupler 14 and the light emitting diode 15D of the second photocoupler 15 is connected through the contact 121 and the resistor 13 in series, and the second contact 122 of the changeover switch 12 and the resistor are connected in series. 16 in series
The light emitting diode 17D of the photocoupler 17 and the fourth
A series circuit with the light emitting diode 18D of the photocoupler 18 is connected. Each of the photocouplers 14,
15, 17, 18 phototransistors 14Tr,
15Tr, 17Tr, and 18Tr have their collectors connected to the positive ends of DC power supplies 23, 24, 25, and 26 via resistors 19, 20, 21, and 22, respectively, and their emitters are connected to the first, fourth, and second terminals, respectively. , and the bases of the third transistors 3, 6, 4, and 5. Each of the DC power supplies 23, 24, 25,
The negative terminals of the transistors 26 are connected to the emitters of the first, fourth, and third transistors 3, 6, 4, and 5, respectively. the first to fourth transistors 3;
4, 5, 6, changeover switch 12, 11th to 4th photocouplers 14, 15, 17, 18, DC power supply 23,
The circuit made up of 24, 25 and 26 forms current direction switching means.

Next, the operation of the apparatus according to the embodiment of the present invention constructed as described above will be described.

First, when the first contact 121 of the changeover switch 12 is closed, the first and second photocouplers 14 and 15 operate, and their phototransistors 14Tr and 15Tr are turned on. However, the first and fourth transistors 3,
6 is turned on, and an arc current flows in the high pressure discharge lamp 7 in the direction shown by the solid arrow "I" in FIG.
At this time, a magnetic field is applied to the high-pressure discharge lamp 7 in the direction shown by the solid arrow "H" in FIG.
Due to the left-hand rule of framing, a force is generated in the direction shown by the solid arrow "F" in Figure 2, and both electrodes 7
The arc between a and 7b is bent upward as shown in FIG. Therefore, the beam emitted through the front glass 11 is a downward beam, which is a so-called passing beam, compared to the beam emitted when the arc indicated by the dotted line in the figure is horizontal.

Conversely, when the second contact 122 of the changeover switch 12 is closed, the third and fourth photocouplers 17 and 18 operate, and their phototransistors 17Tr and 18Tr are turned on. However, the second and third transistors 4,
5 is turned on, and an arc current flows in the high pressure discharge lamp 7 in the direction indicated by the dotted arrow "I" in FIG.
At this time, the direction of the magnetic field does not change, so a force is generated in the high-pressure discharge lamp 7 in the direction shown by the dotted arrow "F" in FIG.
Bend downward as shown. Therefore, the beam emitted through the front glass 11 becomes a so-called traveling beam, which is an upward beam compared to the beam emitted when the arc indicated by the dotted line in the figure is horizontal.

In this way, the arc of the high-pressure discharge lamp 7 is bent upward and downward by switching the direction of the current, thereby switching between the passing beam and the running beam. It is possible to reduce the size and weight of the device and improve economic efficiency. Further, since the input side and the output side are separated by using a photocoupler and a transistor as the current direction switching means, and the arc current switching is performed using a non-contact method, current switching can be performed smoothly.

In the above embodiment, if the changeover switch is replaced with a high-speed operation switch using a flip-flop circuit or the like, the lamp failure time at the time of changeover can be shortened to the point where it can be ignored, and the current changeover can be performed even more smoothly.

Next, another embodiment of the invention will be described with reference to the drawings. Note that the same parts as in the above embodiment are given the same reference numerals, and detailed explanations will be omitted.

As shown in FIG. 5, this consists of a pair of changeover switches 27 and 28 that are mutually interlocked as current direction changeover means.
and the first contact 271 of the changeover switch 27
and the second contact 282 of the changeover switch 28 are connected to one of the output ends of the DC lighting device 2, and the second contact 272 of the changeover switch 27 and the changeover switch 28 are connected to one of the output ends of the DC lighting device 2.
The first contact 281 of the above-mentioned DC lighting device 2 is connected to the other output end of the above-mentioned DC lighting device 2, and both the above-mentioned changeover switches 27, 28
A high pressure discharge lamp 7 is connected between common contacts 27c and 28c.

In this case, since the arc current is directly switched by the changeover switches 27 and 28, there is a problem that arcs are generated at the contacts when switching the contacts, but the structure of the current direction switching means is extremely simple. In this case as well, since the direction of the arc current of one high-pressure discharge lamp 7 can be changed to switch between the passing beam and the running beam, the same effects as in the previous embodiment can be obtained.

In both of the above embodiments, the beam is switched in the vertical direction by applying a magnetic field to the discharge lamp in the horizontal direction, but by applying the magnetic field diagonally, the beam can be switched not only in the vertical direction but also in the horizontal direction. It is also possible to perform switching accompanied by .

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a headlamp device that can be made smaller, lighter, and more economical.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention. Figure 1 is a circuit diagram, Figure 2 is a high-pressure discharge lamp, a is a side view, b is a sectional view, and Figure 3 is a sectional view. FIG. 4 is a schematic diagram showing a passing beam, FIG. 4 is a schematic diagram showing a running beam, and FIG. 5 is a circuit diagram showing another embodiment of the present invention. 2...DC lighting device, 3, 4, 5, 6...
NPN transistor, 7... High pressure discharge lamp, 8...
...E-type core, 9...coil, 12...changeover switch, 14, 15, 17, 18...photocoupler.

Claims (1)

[Claims] 1. A reflecting mirror that is approximately a paraboloid of rotation, a high-pressure discharge lamp that is held horizontally at approximately the focal point of the reflecting mirror and is lit with direct current, and a magnetic field that applies a magnetic field approximately perpendicular to the arc of this high-pressure discharge lamp. The present invention is characterized in that it comprises an applying means and a current direction switching means for switching the direction of the arc current of the high pressure discharge lamp, and switching between a running beam and a passing beam is performed by switching the direction of the arc current by the current direction switching means. Headlight device.