JP4021103B2 - Railway vehicle headlamps - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projector-type railcar headlamp.
[0002]
[Prior art]
In recent years, projector-type headlamps have been adopted as railcar headlamps. As shown in FIG. 8, the projector-type headlamp includes a light source 102 provided on a lamp optical axis Ax extending in the vehicle front-rear direction, and the lamp optical axis Ax with the light from the light source 102 directed forward. A reflector 104 that reflects toward the side, a condenser lens 106 provided on the front side of the reflector 104, and a cylindrical holder 108 that connects the condenser lens 106 to the reflector 102 are provided.
[0003]
[Problems to be solved by the invention]
In the conventional railcar headlamp, as shown in the figure, the irradiation light from the lamp is irradiated forward as a light beam substantially parallel to the lamp optical axis Ax. Although sufficient irradiation light can be obtained for a region, there is a problem that sufficient irradiation light cannot be obtained for a short-range to medium-distance region.
[0004]
The present invention has been made in view of such circumstances, and in a projector-type headlamp for a railway vehicle, sufficient irradiation is performed not only in a long distance area but also in a short distance to a middle distance area of a vehicle front line. An object of the present invention is to provide a railcar headlamp capable of obtaining light.
[0005]
[Means for Solving the Problems]
The present invention is intended to achieve the above object by providing a predetermined sub-reflector.
[0006]
That is, the railcar headlamp according to the present invention is
A light source provided on a lamp optical axis extending in the vehicle front-rear direction, a reflector for reflecting light from the light source forward toward the lamp optical axis, and a condensing lens provided on the front side of the reflector; In a projector-type railcar headlamp comprising a cylindrical holder that connects the condenser lens to the reflector,
In the space above the lamp optical axis between the light source and the reflector, a sub-reflector that reflects light from the light source forward at a predetermined angle downward is provided ,
The sub-reflector is provided in the vicinity of the front end opening of the reflector, and the reflecting surface of the sub-reflector is a parabolic curved surface or an elliptic curved surface with the optical axis at a predetermined angle downward with respect to the lamp optical axis as a central axis. It is characterized by being comprised .
[0008]
The above-mentioned “downward by a predetermined angle” means an angle at which the reflected light from the sub-reflector becomes downward light from the lamp optical axis after passing through the condenser lens.
[0009]
[Effects of the invention]
As shown in the above configuration, in the present invention, in the space above the lamp optical axis between the light source and the reflector, a sub reflector that reflects light from the light source forward by a predetermined angle downward is provided. Irradiation light from the lamp is composed of a light bundle that is substantially parallel to the lamp optical axis and a light bundle that faces downward with respect to this light bundle.
[0010]
Therefore, according to the invention of the present application, in the projector-type railcar headlamp, sufficient irradiation light can be obtained not only in the long-distance area but also in the short-distance to middle-distance areas of the vehicle front track.
[0011]
Moreover, in the present invention, since the sub-reflector is provided in the vicinity of the front end opening of the reflector, the reflected light from the reflector can be used effectively, and the reflecting surface of the sub-reflector is Since it is composed of a parabolic curved surface or an elliptical curved surface having a center axis that is directed downward by a predetermined angle, light distribution control can be performed relatively easily, and light emitted from the lamp is not directed to directions other than the vehicle front track. It is possible to prevent diffusion as necessary.
[0012]
Here, the “parabolic curved surface” means a curved surface in which a cross-sectional shape including the central axis of the sub-reflector is configured by a parabola, and a curved surface having a constant focal length in each circumferential cross section may be used. The curved surface may change. “Elliptical curved surface” means a curved surface having an elliptical cross-sectional shape including the central axis of the sub-reflector. The focal length of each circumferential cross-section may be a curved surface with a constant or variable shape. It may be a curved surface.
[0013]
The “sub-reflector” may be formed integrally with the reflector. However, the sub-reflector is formed separately from the reflector, and a flange portion is formed at the front end portion of the reflecting surface. If the reflector is configured to be sandwiched between the reflector and the holder, the sub reflector can be provided without requiring a major change in the structure of the conventional lamp, and different reflections can be made depending on the lamp distribution. A sub reflector having characteristics can be appropriately replaced.
[0014]
In addition to the above configuration, if the inner peripheral surface of the holder is subjected to a reflection treatment, the reflected light from the inner peripheral surface can also be used as the front irradiation light, and thereby to the short distance region of the vehicle front track Can be further increased.
[0015]
By the way, the headlight for a railway vehicle is configured to be able to switch between a traveling beam and a passing beam in order to prevent glare when passing with an oncoming vehicle or approaching a platform while performing far-distance irradiation during normal traveling. There are many things.
[0016]
Therefore, also in the railway vehicle headlamp according to the present invention, a light shielding plate is provided between the reflector and the condenser lens so as to be retractable so as to shield part of the reflected light from the reflector and remove the upward irradiation light. By doing so, it is possible to switch between the traveling beam and the passing beam with a single lamp.
[0017]
However, the railcar headlamp according to the present invention is not limited to the lamp capable of switching between the traveling beam and the passing beam as described above, and may be a traveling beam dedicated lamp or a passing beam dedicated lamp. .
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is a side sectional view showing a railcar headlamp according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.
[0020]
As shown in these drawings, a railcar headlamp (lamp) 10 according to the present embodiment is a projector-type headlamp, and includes a discharge bulb 12, a reflector 14, a holder 16, and a light condensing unit. A lens 18, a sub reflector 20, a retaining ring 22, a light shielding plate 24, a light shielding plate rotating unit 26, and an aiming unit 28 are provided.
[0021]
The discharge bulb 12 is a metal halide bulb, and is attached to the reflector 14 so that the discharge light emitting portion 12a (light source) is positioned on the lamp optical axis Ax extending in the vehicle front-rear direction.
[0022]
The reflector 14 has a substantially elliptical spherical reflecting surface 14a with the lamp optical axis Ax as a central axis. The reflecting surface 14a has an elliptical cross-sectional shape including the lamp optical axis Ax, and is set so that its eccentricity gradually increases from the vertical cross section toward the horizontal cross section. However, the rear apex of the ellipse forming each of these cross sections is set at the same position. The discharge light emitting unit 12a is disposed at an elliptical first focal point F1 that forms a vertical section of the reflecting surface 14a. As a result, the reflecting surface 14a reflects light from the discharge light emitting part 12a forward toward the lamp optical axis Ax, and in this case, the elliptical shape is included in the vertical section including the lamp optical axis Ax. It is made to converge to the 2nd focus F2.
[0023]
The holder 16 is formed in a cylindrical shape so as to extend forward from the front end opening 14b of the reflector 14, and the inner peripheral surface 16a thereof is subjected to a reflection process by aluminum vapor deposition. The rear end portion of the holder 16 is screwed and fixed to the reflector 14 via the sub reflector 20, and the condenser lens 18 is screwed and fixed to the front end portion via the retaining ring 20.
[0024]
The condensing lens 18 is a plano-convex lens having a convex front surface 18a and a flat rear surface 18b, and the rear focal position thereof is arranged to coincide with the second focal point F2 of the reflecting surface 14a of the reflector 14. Yes. Thereby, the condensing lens 18 allows the reflected light from the reflecting surface 14a of the reflector 14 to be transmitted forward so as to be condensed near the lamp optical axis Ax.
[0025]
The sub-reflector 20 is provided in a space above the lamp optical axis Ax between the discharge light emission part 12a of the discharge bulb 12 and the vicinity of the front end opening part 14b of the reflection surface 14a of the reflector 14, and the discharge light emission part The light from 12a is reflected forward by a predetermined angle downward.
[0026]
The reflecting surface 20a of the sub-reflector 20 has a focal length fs shorter than the focal length f of the reflector 14 and has an optical axis Axs that is a predetermined angle (about 30 °) downward with respect to the lamp optical axis Ax as a central axis. It consists of a parabolic surface. This parabolic curved surface has a cross-sectional shape including the optical axis Axs formed by a parabola. The focal point of the parabola is set at the same position as the first focal point F1 of the reflecting surface 14a of the reflector 14 in the vertical section, but the focal point of the parabola that forms each sectional shape as it moves away from the vertical section toward both sides in the circumferential direction. The distance gradually increases.
[0027]
FIG. 3 is a front view (a) and a side sectional view (b) showing the sub reflector 20 as a single product.
[0028]
As shown in the figure, a flange portion 20b is formed at the front end portion of the reflecting surface 20a of the sub-reflector 20, and the sub-reflector 20 is sandwiched between the reflector 14 and the holder 16 at the flange portion 20b. Yes.
[0029]
That is, the flange portion 20b of the sub reflector 20 has a tab 20c extending forward at the upper end portion thereof, and a pair of screw insertion holes 20d formed at both left and right end portions thereof. The sub-reflector 20 has a flange portion 20b interposed between the front end flange portion 14c of the reflector 14 and the rear end flange portion 16c of the holder 16 when the reflector 14 and the holder 16 are screwed and fixed. In this state, a screw is inserted into the screw insertion hole 20d and fastened together with the reflector 14 and the holder 16.
[0030]
At that time, the tab 20 c is engaged with the holder 16, whereby the holding position of the sub reflector 20 is positioned. That is, a notch 16d having substantially the same width as the tab 20c is formed in the rear end flange portion 16c of the holder 16, and the tab 20c is positioned in the left-right direction by inserting the tab 20c into the notch 16d. At the same time, the tab 20c is positioned in the vertical direction by bringing the tab 20c into contact with the outer peripheral surface of the holder 16.
[0031]
As shown in FIG. 1, the light shielding plate 24 is provided between the reflector 14 and the condenser lens 18, and rotates between the traveling beam position indicated by the solid line and the passing beam position indicated by the two-dot chain line in the same figure. It has come to be able to do. The surface of the light shielding plate 24 is subjected to black non-reflection treatment. And when this light-shielding plate 24 exists in a passing beam position, the upper end edge 24a is located substantially in the 2nd focus F2 of the reflective surface 14a of the reflector 14, and, thereby, the reflected light from the reflective surface 14a The upward irradiation light emitted from the lamp 10 is removed by blocking a part of the light. On the other hand, the light shielding plate 24 does not shield the reflected light from the reflecting surface 14a in a state where it is retracted to the traveling beam position, and allows upward irradiation light emitted from the lamp 10.
[0032]
The light shielding plate 24 is rotated by a light shielding plate rotation unit 26 provided in the vicinity of the reflector 14 and the lower portion of the holder 16.
[0033]
The light shielding plate rotation unit 26 includes a rotation shaft 30 that rotatably supports the light shielding plate 24, and a solenoid 32 that is connected to a portion near the lower end of the light shielding plate 24. The light shielding plate 24 is rotated about the rotation axis 30 between the traveling beam position and the low beam position.
[0034]
The aiming unit 28 is attached to brackets 16b formed at three locations on the outer peripheral surface of the holder 16, and the aiming unit 28 supports the lamp 10 at the front end of the vehicle and adjusts the optical axis of the lamp 10. To get.
[0035]
FIG. 4 is a side sectional view showing an optical path of the irradiation light from the railcar headlamp 10, and FIGS. 5 and 6 are a traveling beam light distribution pattern and a passing beam formed in front of the vehicle by the irradiation light. It is a figure which shows the light distribution pattern for use.
[0036]
As shown in FIG. 4, the reflected light from the reflecting surface 14a of the reflector 14 becomes a light bundle B emitted to the front of the lamp substantially parallel to the optical axis Ax, and the traveling beam basic pattern P (m) shown in FIG. Alternatively, a passing beam basic pattern P (s) shown in FIG. 6 is formed. As described above, when the light shielding plate 24 is at the low beam position, the upward irradiation light component included in the light beam B is removed. As a result, in the basic beam pattern P (s), the traveling light travels. The light distribution pattern is obtained by removing the upward irradiation light region (region above the HH line) in the beam basic pattern P (m).
[0037]
The visibility of the long-distance area on the vehicle front track is ensured by the basic pattern P (m) for traveling beam or the basic pattern P (s) for passing beam. 5 and 6, the traveling beam basic pattern P (m) and the passing beam basic pattern P (s) are displayed as multiple closed curves. This is because the closed curve region in the center has the highest luminous intensity. This indicates that the light intensity gradually decreases toward the periphery.
[0038]
On the other hand, as shown in FIG. 4, the reflected light from the reflecting surface 20a of the sub-reflector 20 becomes a light bundle B1 emitted to the front of the lamp as diffused light downward to some extent with respect to the optical axis Ax. The first additional pattern P1 shown is formed. At this time, the reflected light from the reflecting surface 20a of the sub-reflector 20 is not shielded by the light shielding plate 24 even when the light shielding plate 24 is at the passing beam position. Therefore, the first additional pattern P1 is the traveling beam light distribution pattern and The same light distribution pattern is obtained in any of the passing beam light distribution patterns.
[0039]
The first additional pattern P1 is formed so as to broadly surround the lower end portions of the traveling beam basic pattern P (m) and the passing beam basic pattern P (s) in a substantially fan shape. Therefore, the visibility of the short-distance and middle-distance areas on the vehicle front track is ensured by the first additional pattern P1.
[0040]
Further, as shown in FIG. 4, the light incident on the upper region of the inner peripheral surface 16a of the holder 16 from the discharge light emitting portion 12a and reflected by the inner peripheral surface 16a is diffused light that is considerably downward with respect to the optical axis Ax. As a light bundle B2 emitted forward of the lamp, and forms a second additional pattern P2 shown in FIGS. At this time, the reflected light from the upper region of the inner peripheral surface 16a of the holder 16 is not shielded by the light shielding plate 24 even when the light shielding plate 24 is in the passing beam position. Both the light pattern and the passing beam light distribution pattern have the same light distribution pattern.
[0041]
The second additional pattern P2 is formed considerably below the lower end portions of the traveling beam basic pattern P (m) and the passing beam basic pattern P (s). Therefore, the visibility of the short-distance area | region in a vehicle front track is aimed at by this 2nd additional pattern P2.
[0042]
In addition, even if the light shielding plate 24 is in any position of the traveling beam and the passing beam, the light shielding plate 24 prevents light from entering the lower region of the inner peripheral surface 16a of the holder 16 from the discharge light emitting unit 12a. Unnecessary upward irradiation light is not generated by the reflected light from the lower region of the inner peripheral surface 16a.
[0043]
As described above in detail, the railcar headlamp 10 according to the present embodiment emits light from the discharge light emitting unit 12a into the space above the lamp optical axis Ax between the discharge light emitting unit 12a and the reflector 14. Since the sub-reflector 20 is provided to reflect forward by a predetermined angle downward, the irradiation light from the lamp 10 is a light beam B that is substantially parallel to the light beam optical axis Ax and a light beam B1 that is downward with respect to the light beam B. It will be composed of. For this reason, sufficient irradiation light can be obtained not only in the long-distance area of the vehicle front line but also in the short-distance to middle-distance area.
[0044]
In addition, in the present embodiment, since the sub reflector 20 is provided in the vicinity of the front end opening 14b of the reflecting surface 14a of the reflector 14, the following operational effects can be obtained.
[0045]
That is, the portion near the front end opening 14b on the reflecting surface 14a of the reflector 14 has many portions where the light from the discharge light emitting portion 12a reflected by the portion does not enter the condensing lens 18, and is important for the lamp light distribution performance. Low. Therefore, by providing the sub reflector 20 in the vicinity of the front end opening 14b of the reflecting surface 14a of the reflector 14, the effective reflected light incident on the condenser lens 18 from the reflecting surface 14a of the reflector 14 is minimized. It is possible to obtain the above-described effects while suppressing the above.
[0046]
In the present embodiment, the reflecting surface 20a of the sub-reflector 20 is composed of a parabolic curved surface having a central axis Axs that is downwardly inclined by a predetermined angle with respect to the lamp optical axis Ax. The first additional pattern P1 formed by the bundle B1 can be formed so as to widely surround the lower end portions of the traveling beam basic pattern P (m) and the passing beam basic pattern P (s) in a substantially fan shape. And thereby, the visibility of the short distance and middle distance area | region in a vehicle front track | line can fully be ensured, without making the light beam B1 diffuse unnecessarily to directions other than a vehicle front track | line. Moreover, since the focal length Fs of the sub reflector 20 is set to a value shorter than the focal length f of the reflector 14, the sub reflector 20 can be compactly arranged on the inner peripheral side of the reflector 14.
[0047]
Furthermore, in the present embodiment, since the inner peripheral surface 16a of the holder 16 is subjected to the reflection treatment, the reflected light from the inner peripheral surface 16a can also be used as the front irradiation light, thereby the front of the vehicle. The irradiation light to the short-distance area | region of a track | line can be increased more, and the visibility can be improved.
[0048]
In this embodiment, the sub-reflector 20 is formed separately from the reflector 14, and a flange portion 20b is formed to extend at the front end portion of the reflecting surface 20a. The sub-reflector 20 is reflected at the flange portion 20b. 14 and the holder 16, the sub-reflector 20 can be provided without requiring a major change in the conventional lamp structure, and different reflection characteristics can be provided depending on the lamp distribution. It can replace with the sub reflector 20 which has.
[0049]
Furthermore, the railcar headlamp 10 according to this embodiment includes a light shielding plate 24 that shields a part of the reflected light from the reflector 14 between the reflector 14 and the condenser lens 18 and removes the upward irradiation light. Is provided so as to be retractable, it is possible to switch between the traveling beam and the passing beam with a single lamp.
[0050]
By the way, in this embodiment, the reflective surface 20a of the sub reflector 20 is formed so as to surround the space above the lamp optical axis Ax by 180 ° in the vicinity of the front end opening 14b of the reflective surface 14a of the reflector 14. However, it may be formed only in a part thereof. At this time, since it is the upper end region of the reflecting surface 14a of the reflector 14 that is less important for the lamp light distribution performance, it is preferable to form the reflecting surface 20a of the sub reflector 20 near the upper end.
[0051]
In the present embodiment, the reflecting surface 20a of the sub reflector 20 has a focal length Fs shorter than the focal length f of the reflector 14 and has a central axis Axs that is a predetermined angle downward with respect to the lamp optical axis Ax. Although the case where it was comprised by the object curved surface was demonstrated, if it can irradiate a light bundle with respect to a middle distance area | region from the short distance of a vehicle front track, it will comprise the reflective surface 20a with another curved surface. Also good. For example, as shown in FIG. 7, instead of a parabolic curved surface, the optical axis Axs that is a predetermined angle downward with respect to the lamp optical axis Ax is used as the central axis, and the first focal point F3 and the second focal point F4 are provided on the central axis. It is also possible to configure the reflecting surface 20a with an elliptical curved surface. As the shape of the reflecting surface 20a, an appropriate curved surface may be adopted as appropriate in accordance with a target light distribution pattern in a short to medium distance region of the vehicle front track. From this point of view, the reflecting surface 20a can be configured by a curved surface other than a parabolic curved surface or an elliptic curved surface, such as a conical surface or a spherical surface.
[0052]
Note that the railcar headlamp 10 according to the present embodiment has been described for the case where the light source is the discharge light emitting unit 12a of the discharge bulb 12, but the present embodiment is also implemented when the light source is a halogen bulb filament or the like. By adopting the same configuration as that of the embodiment, it is possible to obtain the same effect as that of the present embodiment.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a railcar headlamp according to an embodiment of the present invention. FIG. 2 is a plan view showing the railcar headlamp. Front view (a) and side sectional view (b) showing the sub reflector as a single item
FIG. 4 is a side sectional view showing an optical path of light emitted from the railcar headlamp. FIG. 5 is a light distribution pattern for a traveling beam formed in front of the vehicle by the light emitted from the railcar headlamp. FIG. 6 is a view showing a light distribution pattern for a passing beam formed in front of the vehicle by light emitted from the railcar headlamp. FIG. 7 is a view showing a modification of the embodiment. Fig. 8 is a diagram similar to Fig. 4 showing a conventional example.
DESCRIPTION OF SYMBOLS 10 Railcar headlamp 12 Discharge bulb 12a Discharge light emission part (light source)
14 Reflector 14a Reflective surface 14b Front end opening 14c Front end flange portion 16 Holder 16a Inner peripheral surface 16b Bracket 16c Rear end flange portion 16d Notch portion 18 Condensing lens 20 Sub reflector 20a Reflective surface 20b Flange portion 20c Tab 20d Screw insertion hole 22 Retaining ring 24 Shading plate 24a Upper edge 26 Shading plate rotating unit 28 Aiming unit 30 Rotating shaft 32 Solenoid Ax Lamp optical axis Axs Optical axis B of sub-reflector Irradiation beam bundle B1 by reflected light from reflecting surface of reflector Sub-reflector Illuminated beam bundle B2 by reflected light from the reflecting surface of the beam Irradiated beam bundle P (m) by reflected light from the inner peripheral surface of the holder Basic pattern for traveling beam P (s) Basic pattern for passing beam P1 First additional pattern P2 2 additional patterns

Claims (4)

A light source provided on a lamp optical axis extending in the vehicle front-rear direction, a reflector for reflecting light from the light source forward toward the lamp optical axis, and a condensing lens provided on the front side of the reflector; In a projector-type railcar headlamp comprising a cylindrical holder that connects the condenser lens to the reflector,
In the space above the lamp optical axis between the light source and the reflector, a sub-reflector that reflects light from the light source forward at a predetermined angle downward is provided ,
The sub-reflector is provided in the vicinity of the front end opening of the reflector, and the reflecting surface of the sub-reflector is a parabolic curved surface or an elliptic curved surface with the optical axis at a predetermined angle downward with respect to the lamp optical axis as a central axis. A railcar headlamp, characterized in that it is configured . The sub-reflector is formed separately from the reflector, and a flange portion is formed at the front end of the reflecting surface of the sub-reflector. The sub-reflector is sandwiched between the reflector and the holder at the flange portion. The railcar headlamp according to claim 1, wherein The railcar headlamp according to claim 1 or 2 , wherein the inner peripheral surface of the holder is subjected to a reflection treatment. The light-shielding plate which shields a part of the reflected light from the reflector and removes the upward irradiation light is provided between the reflector and the condenser lens so as to be retractable. ~ Railway vehicle headlamp according to any one of 3

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