JP2014103106A - Halogen lamp for automobile headlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a halogen lamp for an automobile headlight capable of inexpensively manufacturing a color temperature lamp having preferable visibility and fashionability, capable of enhancing the efficiency of irradiation light collection by avoiding luminance degradation of filament and capable of suppressing the blackening by uniformizing the temperature on valve surface, raising the temperature on an inner surface of a valve and uniformizing a halogen cycle.SOLUTION: An H4 type halogen lamp for an automobile headlight stores a low-beam filament and a high-beam filament in a valve. Therein, a colored film is formed on a light transmission outer surface of the valve such that light emission of a color temperature of 4,500 to 6,700 K is obtained, and light shielding means that has not a light shielding body on a lower part position of the low-beam filament in the valve in a usage state and does not reflect filament light emission is arranged at least on the lower part position of the low-beam filament outside the valve.

Description

The present invention relates to a halogen lamp for an automotive headlamp of H4 type in which a low beam filament and a high beam filament are accommodated in a bulb.

As a conventional halogen lamp for H4 type automobile headlamps, Japanese Patent Laid-Open No. 9-330685 discloses a low-beam filament 31 parallel to the central axis in a heat-resistant transparent bulb 30 such as quartz glass as shown in FIG. And a high beam filament 32, and a low beam filament 31 is provided with a light shielding body including a mirror 33. A blue colored film 37 is formed on the outer surface of the bulb 30 by laminating a blue colored film layer composed of at least one layer of silicon oxide and cobalt oxide or a composite oxide of silicon oxide, cobalt oxide and phosphorous oxide. A halogen bulb that emits high-purity white light with no color unevenness is disclosed.

In Japanese Patent Laid-Open No. 11-176390, as shown in FIG. 5, a low beam filament 31 and a high beam filament 32 are provided in parallel to the central axis in a heat-resistant and transparent bulb 30 such as quartz glass. The filament 31 is provided with a light shielding body composed of a mirror 33. On the outer surface of the bulb, a colored film 37 made of a high color temperature type color temperature conversion film formed by laminating a blue colored film layer made of a composite oxide of at least one layer of silicon oxide, cobalt oxide and phosphorous oxide. Further, a halogen light bulb is disclosed in which a multilayer interference film 38 formed by alternately laminating a high refractive index layer made of titanium oxide and a low refractive index layer made of silicon oxide is further formed thereon, and the color temperature is further increased. ing.

However, in the bulb structure disclosed in Japanese Patent Laid-Open Nos. 9-330685 and 11-176390, the light emitted from the low beam filament 31 is diffused by the mirror 33 below the low beam filament 31, and the luminance of the low beam filament 31 is increased. Therefore, it is difficult for the irradiated light to be collected at the photometric measurement points described in Article 32 of the safety standard, and the photometric value is lowered. The blue colored film 37 is darkened by this bulb structure. In particular, when the color temperature of the emission color is set to 6000 K or more so that it is favored by young users, the luminous intensity standard described in Article 32 of the safety standard could not be satisfied due to a decrease in the bulb transmittance.

Further, when the blue colored film 37 is formed on the outer surface of the bulb 30, mainly the long wavelength light and infrared rays in the visible light irradiated from the low beam filament 31 are absorbed by the blue colored film 37 and the thermal energy is absorbed. Therefore, the surface temperature of the valve 30 and the internal temperature of the valve 30 are higher than those of the clear valve in which the blue colored film 37 is not formed.

However, since halogen lamps for automobile headlamps are generally lit sideways, the upper half of the bulb 30 is hot during lamp lighting, and the temperatures at the lower and tip portions of the bulb 30 are relatively low. When the mirror 33 is present below the low beam filament 31 in the bulb 30, the irradiation light (including infrared rays) from the low beam filament 31 does not reach the lower portion of the bulb 30, and the temperature of the lower portion of the bulb 30 reaches other portions. On the other hand, the halogen cycle becomes uneven because of this, the tungsten cycle becomes uneven, and tungsten deposited and deposited on the lower part of the bulb 30 does not evaporate and accumulates. As a result, tungsten that should return to the low beam filament 31 does not return sufficiently. In some cases, the inner surface of the bulb was blackened, resulting in decreased illuminance and abnormal light distribution. Further, when the blue colored film 37 is dark, the valve temperature is further increased by the blackening of the valve, and as a result, the blue colored film 37 is peeled off due to thermal deterioration. Furthermore, in addition to the valve temperature difference between the upper half and lower half, the valve temperature rises due to the blackening of the valve, resulting in increased valve temperature unevenness. .

As a technique capable of eliminating the disadvantages of the prior art, as shown in FIG. 6 in Japanese Patent Laid-Open No. 6-13058, both ends of a straight tube valve 40 are sealed, and a plurality of filaments are contained in the valve 40. 41. A tubular incandescent bulb characterized in that 41 and 42 are connected in series and accommodated on the central axis of the bulb so that the plurality of filaments 41 and 42 emit light selectively. A tube-type incandescent bulb having a visible light reflecting film 46 for controlling light distribution on a part of the outer surface of the bulb 40 and capable of improving the filament luminous efficiency by the infrared reflecting film is disclosed. Yes.

JP-A-7-220697 discloses an incandescent lamp in which a low beam filament 51 and a high beam filament 52 are housed in a bulb 50 having a spherical surface on which an infrared reflecting film 57 is formed, as shown in FIG. An incandescent bulb is disclosed in which a visible light reflecting film 56 that reflects visible light emitted from the low beam filament 51 in a specific direction is formed on the bulb 50, and the filament luminous efficiency is improved by infrared feedback. .

In the technique described in Japanese Patent Application Laid-Open No. 6-13058, a light shield is not used in the bulb, so that the light irradiated to the lower portion of the bulb 40 is blocked by the shade and the temperature at the lower portion of the bulb 40 becomes extremely low. Can be prevented. However, reducing the diameter of the bulb 40 increases the temperature of the bulb 40. However, the blue coloration further increases the temperature of the bulb 40, causing the blue color to peel off, and is generally used for halogen bulbs. In a glass having a low softening point (for example, PH511 manufactured by Philips), there is a problem that the upper portion of the bulb 40 expands when the blue coloration is dark. In order to prevent this, if the valve diameter is increased and the valve temperature is lowered, the valve becomes longer than the existing valve, which causes a problem that it cannot be attached depending on the vehicle. Further, when glass having a high softening point is used, the number of processing steps increases remarkably.

In JP-A-7-220697, a visible light reflecting film 56 for controlling light distribution is formed on a part of the outer surface of a bulb 50 having a spherical surface on which an infrared reflecting film 57 is formed.

However, since the visible light reflected by the visible light reflecting film 56 is reflected from the lower part of the bulb toward the upper part via the subfilament, the brightness of the filament is lowered. As a result, the luminous intensity described in the safety standard Article 32 There is a characteristic that irradiation light is difficult to collect at the measurement point and the luminous intensity value is lowered. In addition, when a blue colored film is applied by dipping because the bulb has a spherical surface, color irregularities and liquid pools are likely to occur on the straight tube type valve due to variations in shape when the spherical portion is formed. Occurs, and the commercial value is reduced. Furthermore, due to dimensional variations in forming the spherical portion, if the light shielding film is not taken care of when forming the light shielding film in the lower part, a light distribution abnormality occurs due to the light shielding film position shift, which increases the number of manufacturing steps. Furthermore, forming a spherical surface in the vicinity of a high-temperature filament requires attention to glass distortion that occurs during molding, and requires labor for inspection and distortion removal.

Japanese Patent Laid-Open No. 9-330685 JP-A-11-176390 JP-A-6-13058 Japanese Patent Laid-Open No. 7-220697

The present invention eliminates the drawbacks of the prior art, and manufactures a lamp capable of emitting light at a color temperature of 4500K to 6700K with excellent emission and visibility within the white range of Japanese Industrial Standard JIS-D5500. In addition, brightness reduction due to the light shielding body under the low beam is avoided to increase the light collection efficiency, and the bulb surface temperature is made uniform, and the bulb inner surface temperature is raised to make the halogen cycle uniform, thereby reducing blackening. It is another object of the present invention to provide an H4 type halogen lamp for an automotive headlamp that is excellent in durability.

The halogen lamp for automobile headlamps according to the present invention is a halogen lamp for H4 type automobile headlamps in which a low beam filament and a high beam filament are accommodated in a bulb, and the emission color is white of Japanese Industrial Standard JIS-D5500. A colored film is formed on the outer surface of the light transmitting portion of the bulb so that light emission of 4500K to 6700K is obtained within the range, and there is no light shield at the lower position of the low beam filament in the bulb in use, A light-shielding means that does not reflect the emission of the filament is disposed at least below the low-beam filament outside the bulb.

Further, the light shielding means is a light shielding film coated on the outside of the bulb.

Furthermore, the thickness of the light shielding film is 0.5 mm or less.

The light-shielding means is a light-shielding plate disposed outside the bulb and spaced from the bulb.

Further, the light shielding plate is characterized by comprising a cap part covering the top of the bulb and a semi-cylindrical part covering at least the lower part of the low beam filament of the bulb.

Furthermore, the light-shielding plate is disposed with an interval of 2 mm or more and 7 mm or less from the outer surface of the bulb.

In the halogen lamp for automobile headlamps of the present invention, since the light shielding body as disclosed in Patent Document 1 or Patent Document 2 is not disposed at a position close to the filament in the bulb, the brightness of filament light emission is prevented from being lowered. This has the effect of improving the irradiation and condensing efficiency.

Furthermore, in the present invention, a light-shielding body is disposed under the bulb itself, which is the coldest point in the prior arts disclosed in Patent Document 1 and Patent Document 2 when used in an automobile, and the light (including infrared rays) is absorbed. By positively using the heat generation action of the valve, the temperature at the lower part of the valve is raised, thereby promoting the evaporation of tungsten deposited on the lower part of the valve and preventing blackening of the lower part of the valve.

In addition, an expensive visible light reflecting film or infrared reflecting film as disclosed in Patent Document 3 or Patent Document 4 is not used on the bulb surface, and the color temperature that improves the visibility of road white lines and the like is from 4500K. By forming a colored film that can actively absorb long-wavelength light (including infrared rays) in the visible light region so that light emission of 6700K can be obtained, a synergistic effect with the light-shielding body formed in the lower part of the bulb, Damage to the valve due to thermal stress can be prevented by maintaining a good temperature balance not only on the lower surface of the valve but also on the entire valve.

Furthermore, since the surface temperature of the entire bulb can be raised, the halogen cycle on the bulb inner surface is made uniform to promote the evaporation of tungsten deposited on the bulb inner surface and prevent the bulb from blackening, thereby reducing illuminance and abnormal light distribution. Has the effect of preventing.

The side view which shows the halogen lamp for motor vehicle headlamps of 1st Example of this invention. The side view which shows the halogen lamp for motor vehicle headlamps of 2nd Example of this invention. Side view of prior art halogen lamp for automotive headlamps Side view of prior art halogen lamp for automotive headlamps Side view of prior art halogen lamp for automotive headlamps Side view of prior art halogen lamp for automotive headlamps Sectional view showing a conventional halogen lamp for automotive headlamps

FIG. 1 shows an example of a preferred embodiment of a halogen lamp for an automobile headlamp according to the present invention. A low-beam filament 21 for passing, which is made of tungsten, is provided at the front in the axial direction of a cylindrical bulb 20. Further, a high beam filament 22 for traveling is provided at the rear portion in the axial direction, and both ends of each filament are connected to a lead wire 23 made of molybdenum, and the lead wire 23 is molybdenum via a molybdenum foil in the valve seal portion. It is connected to a pin (not shown). Further, the molybdenum pin is connected to the power supply terminal 24 through a base.

There is no mirror (light shielding means) in the bulb 20 below the low beam filament 21, and krypton gas containing 0.03% by volume of dibromomethane (CH2Br2) is contained in the bulb 20 at 5 atm in the atmosphere. The surface of the bulb 20 is formed with a colored film made of a pigment composed of cobalt fine particles and an organic solvent so that the emission color of the lamp is 6700K.

A heat-resistant light-shielding film 25a for removing glare light is formed on the top of the outer periphery of the bulb 20, and the light distribution for anti-glare for the oncoming vehicle conforming to the specification of the outer periphery of the bulb 20 in use. A heat-resistant light-shielding film 25b for low beam distribution is formed in the lower half of the outer periphery of the bulb 20 so that the characteristics can be obtained. The light shielding film 25 (25a, 25b) is made of a ceramic heat resistant paint (for example, Seraphy Coat made by Shinagawa Refractories). If the film thickness exceeds 0.5 mm, the paint is easily wiped and peeled off. .5 mm or less is desirable. The thickness of the light shielding film 25 is preferably selected so that the temperature difference of the entire bulb 20 is as small as possible.

In the second embodiment, as shown in FIG. 2, in place of the light shielding film 25 having the same structure as that of the first embodiment, a light shielding plate 26 is disposed outside the bulb 20 with an appropriate distance from the bulb 20. It is. The light shielding plate 26 has a cap portion 26a that covers the top of the bulb 20 for removing glare light, and a light distribution characteristic for anti-glare for an oncoming vehicle that complies with the standard in use. A semi-cylindrical portion 26b for low beam light distribution covering the lower half position of the outer peripheral portion is arranged. In this structure, if the light shielding plate 26b is brought into contact with the bulb 20, the lower half position of the bulb 20 becomes higher than the upper portion due to the heat storage action of the light shielding plate 26b. Arrange them at appropriate intervals. From experiments, it was confirmed that the distance S was appropriately 2 mm or more and 7 mm or less. (If the light-shielding plate exceeds 7 mm, the cut line tends to blur.)

When the halogen lamp having the above structure was lit at a power supply voltage of 13.2 V, the results shown in Table 1 were obtained.

For comparison with Example 1 and Example 2, a halogen lamp as shown in FIG. 3, that is, a low beam filament 11 made of tungsten at the front of the cylindrical bulb 10 in the axial direction. Further, a high beam filament 12 for traveling is provided at the rear part in the axial direction, the high beam filament 11 is connected to both ends of a lead wire 14 made of molybdenum, and the low beam filament 11 is connected to a lead wire 14 made of molybdenum. One end is connected, and the other end is connected to the lead wire 14 via a mirror 13 (light-shielding body).

The lead wire 14 is connected to a molybdenum pin (not shown) through a molybdenum foil in the valve seal portion. Further, the molybdenum pin is connected to the power supply terminal 16 through a base.

In the valve 20, krypton gas containing 0.03% by volume of CH 2 Br 2 is sealed in the atmosphere at 5 atm. The surface of the valve 20 is cobalt fine particles and an organic solvent as in the first and second examples. A colored film made of a pigment is formed so that the emission color of the lamp is 6700K.

A heat-resistant light-shielding film 15 for removing glare light is formed on the top of the outer peripheral portion of the bulb 20, and the mirror 13 disposed inside the bulb 10 is an oncoming vehicle that conforms to the standard in use. It arrange | positions in the downward position of the low beam filament 11 so that the light distribution characteristic for glare-proof with respect to can be acquired.

Here, in the two embodiments of the present invention and the conventional example, in order to confirm the luminous intensity standard described in Article 32 of the safety standard, in addition to the measurement of luminous intensity, the color temperature, the presence or absence of glare, The results of comparative measurement were as shown in Table 1 below.

From this, it can be seen that the halogen lamp for automotive headlamps of the present invention has a luminous intensity of 64 hcd or more, which is a safety standard, even when the emission color is 6700K, and a luminous intensity with no practical problem can be obtained.

If the shade covering the lower half of the lamp bulb is less than 2 mm from the lamp surface, even if a metal such as Inconel with high heat resistance is used, oxidation may occur on the shade surface, which may cause discoloration and smoke generation. 2 mm or more is preferable. Also, by design, when cutting out the shade, at least the lower half of the low beam filament must be shielded from light. If the outer diameter of the shade is not less than 25 mm, it may interfere with the shade attached to the lamp depending on the vehicle.

Visibility at night was confirmed by attaching a genuine halogen lamp (3000K yellowish light) and a halogen lamp with emission colors of 3500K, 4000K, 4500K, 5000K, 5500K, 6000K, and 6700K to the vehicle. It was found that a light emitting color lamp of 4500K or more is easy to distinguish a road white line and feels bright.

From this, it was found that increasing the color temperature is involved not only in improving fashionability but also in improving visibility. Regarding visibility, it is known in various industrial fields using light sources that not only the amount of light but also the emission color, brightness, etc., and in the halogen lamps for automobiles, as described above, 4500K to 6700K. The light emission color in the present invention is within the white range of Japanese Industrial Standard JIS-D5500, and a colored film is formed on the entire outer surface of the light transmitting portion of the bulb so that light emission of a color temperature of 4500K to 6700K can be obtained. It is desirable that a multilayer interference film or other coating film or protective film may be provided on the outer surface of the colored film on the valve surface using existing conventional technology.

INDUSTRIAL APPLICABILITY The present invention can be widely used industrially as a lamp for an H4 type automobile headlamp that has high color temperature light emission excellent in visibility and fashionability and is inexpensive.

10: bulb, 11: filament for low beam, 12: filament for high beam, 13: mirror, 14: lead wire, 15: light shielding film, 16: feeding terminal, 17: colored film, 20: bulb, 21: filament for low beam, 22: High beam filament, 23: Lead wire, 24: Power supply terminal, 25: Light shielding film, 25a: Light shielding film (for removing glare light), 25b: Light shielding film (for low beam light distribution), 26: Light shielding plate, 26a: Light shielding plate (for removing glare light), 26b: Light shielding plate (for low beam distribution), 27: Colored film, 30: Bulb, 31: Low beam filament, 32: High beam filament, 33: Mirror, 34: Lead wire, 35: light shielding film, 37: colored film, 38: multilayer interference film, 40: bulb, 41: low beam filament, 42: high beam film 43: lead wire, 46: visible light reflecting film, 47: multilayer interference film, 50: bulb, 51: filament for low beam, 52: filament for high beam, 53: lead wire, 54: feeding terminal, 56: visible light Reflective film, 57: Infrared reflective film

Claims (6)

The H4 type automotive headlamp halogen lamp that houses the low beam filament and the high beam filament in the bulb, the emission color is within the white range of Japanese Industrial Standard JIS-D5500, and the color temperature is 4500K to 6700K. A colored film is formed on the outer surface of the light transmission part of the bulb so that a light-shielding body is not provided at the lower position of the low beam filament in the bulb in use, and the filament emits light at least at the lower position of the low beam filament outside the bulb. A halogen lamp for an automobile headlamp, characterized in that a non-reflecting light shielding means is arranged. 2. The halogen lamp for an automotive headlamp according to claim 1, wherein the light shielding means is a light shielding film applied to the outside of the bulb. The halogen lamp for an automobile headlamp according to claim 2, wherein the thickness of the light shielding film is 0.5 mm or less. 2. The halogen lamp for an automobile headlamp according to claim 1, wherein the light shielding means is a light shielding plate arranged outside the bulb and spaced from the bulb. 5. The halogen lamp for an automotive headlamp according to claim 4, wherein the light shielding plate includes a cap portion that covers a top portion of the bulb and a semi-cylindrical portion that covers at least a lower portion of the low beam filament of the bulb. 6. The halogen lamp for an automotive headlamp according to claim 5, wherein the light shielding plate is disposed at an interval of 2 mm or more and 7 mm or less from an outer surface of the bulb.

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