JPH09320306A - Vehicle lamp having a discharge bulb - Google Patents

Abstract

(57) Abstract: A vehicular lamp having a discharge bulb requires a shield member for preventing the emission of electromagnetic waves from the discharge bulb, which is made of metal plating provided on the outer surface of the lamp body. Then, the electromagnetic wave leaks due to the peeling of the plating. SOLUTION: The discharge bulb 5 is installed inside a lamp body.
A shield plating layer 13 made of an electroless plating layer is formed on the outer surface of the attached reflector 3 and the shield plating layer 13 is grounded. By controlling the film thickness or the surface resistance value of the shield plating layer 13 to a required value, it is possible to effectively shield the electromagnetic waves emitted from the discharge bulb 5 toward the surroundings. Since the shield plating layer 13 is not exposed to the outside of the lamp body, leakage of electromagnetic waves due to peeling is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp suitable for use as a headlight of an automobile, and more particularly to a vehicular lamp that prevents the influence of electromagnetic waves from a lamp having a discharge bulb as a light source.

[0002]

2. Description of the Related Art In recent years, as a headlight of an automobile, application of a lamp using a discharge bulb as a light source, which has good luminous efficiency and color rendering properties and has a long life, has been studied. However, since this type of lamp requires a high voltage for causing discharge in the discharge bulb, it is necessary to attach a lighting circuit for boosting the on-vehicle battery voltage to the required high voltage. . Then, in this lighting circuit, a high voltage is generated on the secondary side, electromagnetic waves accompanying this high voltage are radiated to the outside, and affect various electronic devices of the vehicle as noise, which interferes with normal operation of these electronic devices. become. For example, noise may be generated in the radio, or noise may be mixed into the signal system of a microcomputer for various controls installed in an automobile, causing so-called EMI failure.

[0003] Such an electromagnetic wave also occurs in a discharge bulb to which the above-mentioned high voltage is applied, and the above-mentioned EMI disturbance is caused by the electromagnetic wave from the discharge bulb. Therefore, measures have been taken to suppress the emission of electromagnetic waves from the discharge bulb by disposing a shield plate or a shade made of a conductive material around the discharge bulb. However, with this measure, it is necessary to dispose these parts in the lamp, which leads to an increase in the number of parts and an increase in assembling work, and also effectively prevents the emission of electromagnetic waves from the gap between these parts. There is a problem that it is difficult to do. For this reason, a technology of forming a highly durable metal plating layer on the surface of the lamp body that houses the discharge bulb, and using this metal plating layer as an electromagnetic shielding layer to suppress the emission of electromagnetic waves from the discharge bulb to the outside Is proposed.

[0004]

However, in this technique, since metal plating is formed on the surface of the lamp body, that is, on the outer surface, physical contact between the lamp and the vehicle body when mounting the lamp on the vehicle body and However, there is a problem that the metal plating layer is peeled off due to the weather resistance after the attachment, and the electromagnetic wave is leaked from the peeled part. Therefore, conventionally, in order to obtain a metal plating layer having excellent durability as described above, it is necessary to take measures such as plating by electrolytic plating and increasing the thickness of the plating layer.
There is a problem that the plating operation becomes troublesome or the cost increases due to an increase in the plating material.

An object of the present invention is to provide a vehicular lamp having such a discharge bulb as a light source, which has improved electromagnetic wave shielding performance.

[0006]

SUMMARY OF THE INVENTION The present invention provides a vehicular lamp in which a reflector is provided in a lamp body, and a discharge bulb as a light source is provided in the reflector.
At least one of the outer surface of the reflector and the inner surface of the lamp body has a metal plating layer. It is preferable that the metal plating layer is an electroless plating layer and has a surface resistance value of 15 mΩ / □ or less or a film thickness of 0.85 to 2 μm.

[0007]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway front view of an embodiment in which the present invention is applied to a four-lamp headlight of an automobile.
2 and 3 are horizontal and vertical sectional views taken along the lines AA and BB of FIG. 1, respectively. In these figures, an integrated reflector 2 in which two rotary parabolic reflectors 3 and 4 are continuously arranged is provided inside the lamp body 1, and is located outside the vehicle body when mounted on a vehicle. The reflector 3 on the side of the passing beam lamp LL is provided with a discharge valve 5, and the reflector 4 on the side of the traveling beam lamp HL located inside the automobile body is provided with a halogen valve 6.
However, each is detachably attached. All of these valves 5 and 6 are attached using the valve mounting holes 3a and 4a opened on the back side of the reflectors 3 and 4, respectively.

On the back surface of the lamp body 1 facing the bulbs 5, 6, there are provided opening portions 1 for inserting the bulbs.
a, 1b are provided, and the valves 5, 6 can be attached and detached through the openings 1a, 1b. And
Opening 1 of discharge bulb 5 on low beam lamp LL side
a, a removable back cover 7 is mounted via a seal ring 8, and a rubber cover 9 is mounted on the opening 1b on the side of the traveling beam lamp HL, whereby these openings 1a, 1b are waterproof. It is sealed with. The socket 5a of the discharge bulb 5 of the passing beam lamp LL has a connector 1 connected to a high voltage cord, the details of which will be described later.
8 is mounted, the socket connector 6a of the halogen lamp 6 of the traveling beam lamp HL is projected to the outside of the rubber cover 9, and a connector (not shown) is connected to this. A lens 10 is attached to the front opening of the lamp body 1 to form a lamp chamber.

As shown in a partially enlarged view in FIG.
The integrated reflector 2, that is, the reflectors 3 and 4
The aluminum film 12 is applied or vapor-deposited on each inner surface to form a reflection surface. On the other hand, the outer surface of the reflector 3 is electroless plated to form the shield plating layer 13. The thickness and plating layer structure of the shield plating layer 13 are set so as to have a required surface resistance value, as will be described later, whereby the shield plating layer 13 surrounds at least the periphery of the discharge bulb 5. Is configured as follows. Further, a metal socket fixture 11 is fixed in the bulb mounting hole 3a provided in the reflector 3, and the discharge bulb 5
Is elastically supported on the inner edge of the valve mounting hole 3a by a retainer spring 14 that is locked to the socket fixture 11.

The socket 5a of the discharge bulb 5
A connector 18 is fitted in the. This connector 18 is a high voltage cord 19 extended from a lighting circuit 20 built in a lighting circuit case 23 attached to the bottom surface of the lamp body 1.
Is connected. The high voltage cord 19 is inserted into a flexible tubular metal mesh shield tube 21,
The metal net shield cylinder 20 is grounded on the side of the lighting circuit 20 to prevent the electromagnetic waves from being radiated from the high voltage cord 19. In addition, the connector 18
The outer side of the cover body 2 covers the back of the discharge bulb 5.
2 is covered, and the opening edge of the socket fixture 11 is supported by the socket fixture 11 to be supported on the back surface of the reflector 3. A metal plating layer 24 is formed on the outer surface of the cover body 22, and the metal mesh shield cylinder 21 is partially formed on the metal plating layer 24.
It is brought into a grounded state by being contacted with and electrically connected to. Further, when the cover body 22 is supported by the reflector 3, the metal plating layer 24 on the outer surface thereof is brought into contact with the shield plating layer 13 of the reflector 3 via the socket fixture 11, and the shield plating layer 13 is grounded. I am trying.

Further, on the front side of the discharge bulb 5, a metallic shade 17 for obtaining a desired light distribution characteristic is disposed, and it is projected rearward from a shielding portion 171 of the shade 17. The pair of legs 172 are fixed to the reflector 3 by the socket fixture 11 in the valve mounting hole 3 a of the reflector 3. Then, in this fixed state, it is brought into contact with the shield plating layer 13 formed on the outer surface of the reflector 3, and is grounded via this shield plating layer 13.

Here, as the shield plating layer 13 and the metal plating layer 24, a plating layer formed by an electroless plating method is adopted. As is well known, the electroless plating method is effective when plating the surface of a non-conductive material such as resin, and various film configurations have been proposed. Here, as shown in FIG. 4B, the cross-sectional structure of a portion C of FIG. 4A, that is, a part of the reflector 3 is formed with a plating adhesive coating layer 13a on the surface of the reflector 3 made of resin. The electroless copper layer 13b and the electroless nickel layer 13c are sequentially formed on the surface of the paint layer 13a by electroless plating.

Therefore, in the headlamp of the present embodiment having the above-described structure, the shield plating layer 13 on the outer surface of the reflector 3, the metal plating layer 24 on the outer surface of the cover body 22, and the metal shade 17 surround the discharge bulb 5. Or, the back area and a part of the front area are covered. The metal plating layer 24 is grounded through the metal net shield cylinder 21 that covers the high voltage cord 19, and the shield plating layer 13 is grounded through the metal plating layer 24 and the socket fixture 11. Further, since the metal shade 17 is grounded via the shield plating layer 13, the discharge bulb 5 is surrounded by the shield layer made of a conductive layer held at the ground potential, whereby the discharge bulb 5 or its Radiation of electromagnetic waves from the socket 5a is suppressed.

In this case, since the shield plating layer 13 and the metal plating layer 24 for shielding the electromagnetic wave are both formed on the surface of the member existing inside the lamp body 1, these plating layers 13 are formed. , 24 are not exposed to the outside of the lamp. Therefore, when the lamp is attached to the vehicle body, or even after the lamp is attached to the vehicle body, these plated layers hardly interfere with the vehicle body or other objects to be peeled off, and leakage of electromagnetic waves is prevented. A highly effective electromagnetic wave shield effect can be obtained.

Now, the shield plating layer 13 and the metal plating layer 24 will be described. According to the experiments conducted by the present inventor, in order to avoid the above-mentioned electromagnetic interference in the automobile lamp, the shielding effect of electromagnetic waves in the shield layer formed of these plating layers is about -70d.
It has been confirmed that about B is required. However, if the above-mentioned shield layer, that is, the plating layer is to be produced based on the value of the shield effect, it is difficult to measure the shield effect, so that it has skill and there is a difference between individuals in the measured value. It is difficult to obtain a plated layer that provides the shield effect. Therefore, the present inventor obtained a relationship between the shield effect and the surface resistance value of the plating layer as shown in FIG. As can be seen from this figure, in order to obtain the above-mentioned shield effect of -70 dB, the surface resistance value of the plating layer should be 13.4 mΩ / □ or less,
Even if some error is expected, it can be seen that it may be about 15 mΩ / □ or less. Therefore, if the plated layer is produced based on the surface resistance value of the plated layer, a stable shield effect can be obtained.

When the film thickness of the plating layer corresponding to the above-mentioned surface resistance value was measured, FIG.
Was obtained. From this result, it is understood that the thickness of the plating layer should be 0.85 μm or more in order to secure the surface resistance value of 13.4 mΩ / □ or less. The thicker this film is, the lower the surface resistance value is and the higher the shield effect is.
Even if the film thickness is more than μm, the shield effect is not significantly improved, and the consumption of the plating material is increased.
In addition, the plating time becomes long, resulting in high cost. On the other hand, if the film thickness is smaller than the above range, a desired surface resistance value cannot be obtained, and a satisfactory shield effect cannot be obtained. Therefore, it is preferable to control the thickness of the plating layer within the range of 0.85 to 2 μm.

Here, when managing the above-mentioned plated layer, it is preferable to manage the surface resistance value of the plated layer. That is, the surface resistance value is, for example, “Loresta A
It can be easily measured by using a surface resistance meter such as "P". On the other hand, when controlling the plating layer based on the film thickness, it is necessary to destroy at least one of the products manufactured in the same lot and measure the film thickness, which decreases the manufacturing yield. Will be done. Therefore,
Managing the plated layer based on the surface resistance value is advantageous in that the manufacturing yield is not reduced.

In the above embodiment, the shield plating layer 13 is formed on the outer surface of the reflector 3 to which the discharge bulb is attached.
However, a shield plating layer may be formed on the inner surface of the lamp body 1. However, in this case, it is necessary to connect the shield wiring to a part of the shield plating layer in order to ground the shield plating layer.
Even with this configuration, since the shield plating layer surrounds the periphery of the discharge bulb, it is possible to prevent electromagnetic waves from the discharge bulb from being radiated to the outside of the lamp. Further, since the shield plating layer is not exposed to the outer surface of the lamp body, peeling of the shield plating layer can be prevented when the lamp is attached to the vehicle body or after the attachment, and a highly reliable shield effect can be obtained. Things will come.
Further, by adopting the above-mentioned electroless plating layer as the shield plating layer and controlling the film thickness of the electroless plating layer at that time, the surface resistance value can be controlled within a required range, It goes without saying that the shield effect can be easily obtained.

If a shield plating layer is formed on each of the outer surface of the reflector 3 and the inner surface of the lamp body 1,
Since a double shield is formed for the discharge bulb 5, it becomes possible to prevent the radiation of electromagnetic waves more effectively.

Further, as shown in FIG. 6, the present invention can be similarly applied to a lamp in which a projection type lamp 15 using a discharge bulb 5 as a light source is incorporated in a lamp body 1. This projection type lamp 15
Is a reflector 151, a lens holder 152, a lens 15
However, by forming the shield plating layer 13 on the outer surface of the reflector 151 made of resin, it is possible to prevent the electromagnetic wave from the discharge bulb 5 from being radiated to the surroundings. Also, this shield plating layer 1
Since 3 is not exposed to the outside of the lamp body 1 as in the above-described embodiment, peeling of the shield plating layer 13 during or after mounting the lamp can be prevented, and the reliability of the electromagnetic wave shielding effect can be improved. You can

Further, in the case of this embodiment, since the cover body for covering the connector 18 is not provided, the metal plating layer 16 is formed on the inner surface of the back cover 7 attached to the opening 1a of the lamp body 1. ing. The metal plating layer 16 and the shield plating layer 13 are electrically connected to each other by the cords 25 and 26, and are grounded by a shield cylinder or the like not shown. Further, in this embodiment, the metal plating layer 28 is also formed on the inner surface of the extension 27 arranged between the projection lamp 15 and the lamp body 1, and is electrically connected to the shield plating layer 13 by the cord 29 to be grounded. I am trying. Therefore, these shield plating layer 13 and metal plating layer 1
6, 28, it is possible to effectively suppress the emission of electromagnetic waves around or behind the discharge bulb 5.

[0022]

As described above, according to the present invention, since the metal plating layer as the shield plating layer is formed on the inner surface of the lamp body or the outer surface of the reflector installed inside the lamp body, the present invention can be performed in a discharge bulb. This metal plating layer can block electromagnetic waves from being emitted to the outside,
It is possible to effectively prevent EMI damage to an electronic device. Further, since the metal plating layer is not exposed to the outside of the lamp body, there is almost no peeling of these plating layers when the lamp is attached to the vehicle body or after the lamp body is attached. Electromagnetic waves are prevented from leaking, and a highly reliable electromagnetic wave shielding effect can be obtained.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a lamp of the present invention.

FIG. 2 is a horizontal sectional view taken along the line AA in FIG.

FIG. 3 is a vertical sectional view taken along the line BB in FIG.

FIG. 4 is an enlarged sectional view of a main part and an enlarged sectional view of a C portion thereof.

FIG. 5 is a diagram showing the relationship between the electromagnetic wave shielding effect and the surface resistivity of the metal plating layer, and the relationship between the surface resistivity of the metal plating layer and the plating film thickness.

FIG. 6 is a vertical cross-sectional view of another embodiment of the present invention.

[Explanation of symbols]

 1 Lamp Body 3, 4 Reflector 5 Discharge Valve 7 Back Cover 11 Socket Fixture 12 Aluminum Film 13 Shield Plating Layer 15 Projection Lamp 17 Metal Shade 18 Connector 19 High Voltage Code 20 Lighting Circuit 21 Shield Tube 22 Cover Body 24 Metal Plating Layer 27 Extension 28 Metal plating layer

Claims (4)

[Claims] 1. A reflector is provided in the lamp body,
A vehicle lamp having a discharge bulb as a light source provided in the reflector, wherein the reflector has a metal plating layer on at least one of an outer surface of the reflector and an inner surface of the lamp body. 2. A vehicle lamp having a discharge bulb according to claim 1, wherein the metal plating layer is an electroless plating layer. 3. The metal plating layer has a surface resistance value of 15 mΩ /
□ A vehicle lamp having the discharge bulb according to claim 2, which is as follows. 4. The metal plating layer has a film thickness of 0.85 to 2 μm.
The vehicle lamp having the discharge bulb according to claim 3, which is in the range of.