Abstract:
A headlight structure for ensuring easy structural designing of a light guide member to enhance the degree of the freedom of shape. Reflectors and left and right lenses are disposed respectively on the left and right sides of the center of a vehicle body. Second light sources are attached respectively to the left and right of a light guide member which is roughly W-shaped. Attachment portions and connection portions are hidden by a light-blocking light cover. The left and right reflectors and left and right including shining portions that are visible through the lenses wherein light evenness can be enhanced within an externally visible region. The headlight can be easily enlarged in size and in diameter. The second light sources make it is easy to design the structure of the light guide member for enhancing the degree of the freedom of shape.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2014-197118 filed Sep. 26, 2014 the entire contents of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a headlight structure for a vehicle that is suitable for a saddle type vehicle. 
         [0004]    2. Description of Background Art 
         [0005]    Vehicles generally have a headlight or headlights (headlamp) at a front portion or portions thereof. In recent years, a structure has come to be proposed in which a light guide member is also provided to permit a headlight to partially shine. See, for example, Japanese Patent Laid-Open No. 2013-178874, FIGS. 3 and 5. 
         [0006]    As shown in FIG. 5 of Japanese Patent Laid-Open No. 2013-178874, four second light sources (118) (the numerals in parentheses appearing here and hereafter are reference symbols used in Japanese Patent Laid-Open No. 2013-178874) are provided on a base member (120). Semicircular arched light guide members (130 a,    130   b ) are attached to the base member (120). Since one end and the other end of the light guide member (130 a ) abut on the second light sources (118), the light guide member (130 a ) shines as a whole. The same applies to the light guide member (130 b ). 
         [0007]    As illustrated in  FIG. 3  of Japanese Patent Laid-Open No. 2013-178874, the shining light guide members (130 a,    130   b ) are visible through a lens (102). The light emitted from the second light sources (118) and entering the semicircular arched light guide member (130 a ) via both ends of the light guide member (130 a ) travels on through the light guide member (130 a ), to reach an uppermost position of the light guide member (130 a ). The light entering the semicircular arched light guide member (130 b ) via both ends of the light guide member (130 b ) travels on through the light guide member (130 b ), to reach a lowermost position of the light guide member (130 b ). 
         [0008]    Light is known to be lowered in brightness, due to diffusion or consumption, as it travels on. It is supposed, therefore, that the second light sources (118) appear brighter than other parts. In Japanese Patent Laid-Open No. 2013-178874, the light guide portion (116) is divided into two parts, as a contrivance to suppress color shading. 
         [0009]    Where the headlight is enlarged in size or in diameter, the number of parts into which the headlight is divided may be increased, whereby color shading can be suppressed. It is to be noted in this case, however, that the number of the second light sources (118) is increased. 
         [0010]    Thus, in the structure according to Japanese Patent Laid-Open No. 2013-178874, structural designing of the light guide member (116) is difficult to carry out, and the degree of freedom of shape is lowered. 
         [0011]    On the other hand, headlights are being diversified in shape. Accordingly, there is a need for a headlight structure which ensures easy structural designing of a light guide portion (light guide member) and makes it possible to enhance the degree of freedom of shape. 
       SUMMARY AND OBJECTS OF THE INVENTION 
       [0012]    It is an object of an embodiment of the present invention to provide a headlight structure which ensures easy structural designing of a light guide member and makes it possible to enhance the degree of freedom of shape. 
         [0013]    According to an embodiment of the present invention, there is provided a headlight structure for a vehicle, including a first light source accommodated in a housing for emitting headlight rays; a light-blocking light cover for covering a front surface of the housing; a reflector disposed between the light cover and the housing, and reflects forward the rays emitted by the first light source; and a lens provided on the light cover for permitting transmission of the rays therethrough while converging the rays. The headlight structure for a vehicle includes a light guide member mounted on the housing so as to fringe the periphery of the reflector for permitting light to travel on therethrough and shine; a second light source disposed in such a part as to be hidden behind the light cover when viewed from the vehicle front side for emitting light guide member rays toward the light guide member; and a control unit for controlling turned-on states of the first light source and the second light source. 
         [0014]    According to an embodiment of the present invention, the headlight structure for a vehicle includes the reflector that is a lower half concave mirror obtained by removing an upper half from a concave mirror; the first light source is a light emitting diode for emitting rays downwardly; and the second light source is disposed above the reflector. 
         [0015]    According to an embodiment of the present invention, the headlight structure for a vehicle includes the first light source, the reflector and a lens that are disposed on each of left and right sides of a vehicle body center line of the vehicle; the light guide member is roughly W-shaped when viewed from the vehicle front side; and the second light source is attached to each of left and right sides of the light guide member. 
         [0016]    According to an embodiment of the present invention, the headlight structure for a vehicle includes left and right reflectors, one is a high-beam reflector for exclusive use for a high beam, and the other is a high/low-beam reflector for combined use for high and low beams. The control unit, when a high beam mode is selected, performs a control such as to turn on the left and right first light sources and to turn on the second light source and the control unit, when a low beam mode is selected, performs a control such as to turn on the first light source on the side of the high/low-beam reflector, turn on the second light source, and turn off the first light source on the side of the high-beam reflector. 
         [0017]    According to an embodiment of the present invention, the headlight structure for a vehicle includes a shining portion which permits shining when light is introduced; and a connection portion which interconnects the second light source and the shining portion, the connection portion being circular in section. 
         [0018]    According to an embodiment of the present invention, the second light source is covered by the light cover. Even when the second light source is brighter than other portions, therefore, it is invisible externally. As a result, unevenness in brightness within an externally visible region can be suppressed. Since the unevenness in brightness can be reduced, the headlight can be easily made larger in size or in diameter. 
         [0019]    Since it is easy to determine the position of the second light source, structural designing of the light guide member is easy to carry out, and the degree of freedom of shape can be enhanced. 
         [0020]    According to an embodiment of the present invention, the reflector is a lower half concave mirror. Therefore, a space on the upper side of the reflector can be utilized, and the second light source can be disposed in the upper-side space. In addition, the first light source is a light emitting diode which emits rays downwardly, and, accordingly, the first light source can also be disposed in the upper-side space. The second light source can be disposed closer to the first light source on a height basis, so that a power feeding system can be arranged in a more intensive form. 
         [0021]    According to an embodiment of the present invention, the light guide member is roughly W-shaped as viewed from the vehicle front side, and the second light sources are attached respectively to the left and right portions of the light guide member. When the light guide member is thus W-shaped, its left and right ends and its center (three portions in total) can be covered with the light cover. Thus, the second light sources, which are brighter than the other portions, and the central portion, which is darker than the other portions, are hidden by the light cover. As a result, unevenness in brightness can be suppressed more assuredly. Even where the headlight is elongated in the left-right direction, it is sufficient to arrange only two second light sources. 
         [0022]    According to an embodiment of the present invention, the high-beam reflector and the high/low-beam reflector are arranged juxtaposedly in the left-right direction. In addition, the light guide member is made to shine both in the high beam mode and in the low beam mode. Consequently, it is possible to optimize the light distribution of the headlight on each of the left and right sides for the exclusive use (for high beam or for low beam), and it is possible, because of the presence of the light guide member, to enhance visibility in the low beam mode. 
         [0023]    According to an embodiment of the present invention, the light guide member includes the shining portion which permits shining when light is introduced, and the connection portion interconnecting the second light source and the shining portion with the connection portion being circular in section. The circular cross section (particularly, true circular cross section) enables guiding of a larger quantity of light than a rectangular or polygonal cross section, thereby enabling the shining portion to shine at a higher intensity. 
         [0024]    Although the connection portions are brighter than the other portions, they are covered with the light cover. Thus, unevenness in brightness of the light guide member can be restrained. 
         [0025]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0027]      FIG. 1  is a left side view of a saddle type vehicle. 
           [0028]      FIG. 2  is a front view of the saddle type vehicle. 
           [0029]      FIG. 3  is an exploded view of a headlight. 
           [0030]      FIG. 4  is a perspective view of a light guide member. 
           [0031]      FIG. 5  is a front view of the headlight. 
           [0032]      FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 5 . 
           [0033]      FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 5 . 
           [0034]      FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 5 . 
           [0035]      FIG. 9  is a back elevation of the headlight. 
           [0036]      FIG. 10  is a sectional view taken along line  10 - 10  of  FIG. 5 . 
           [0037]      FIGS. 11(   a ) and  11 ( b ) show operation diagrams of the headlight. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0038]    An illustrative embodiment of the present invention will be described below, referring to the attached drawings. Note that the drawings should be looked at in accordance with the orientation of reference symbols. 
         [0039]    As shown in  FIG. 1 , a saddle type vehicle  10 , which is a vehicle to be ridden by a driver seated astride a seat  16 , includes a front fork  12  steerably mounted to a front portion of a body frame  11  with a front wheel  13  rotatably mounted on lower portions of the front fork  12 . A steering handlebar  14  is attached to an upper portion of the front fork  12  with a fuel tank  15  and the seat  16  disposed sequentially on the rear side of the steering handlebar  14  and supported by the body frame  11 . An engine  17  is disposed under the fuel tank  15  and supported by the body frame  11 . A swing arm  18  extends rearwardly from the body frame  11  with a rear wheel  19  rotatably mounted on the swing arm  18 . A front cowl  22  is disposed forwardly of the fuel tank  15  so as to surround the front fork  12  with a windscreen  23  mounted to an upper portion of the front cowl  22 . A headlight  40  is mounted to a front portion of the front cowl  22 . 
         [0040]    As depicted in  FIG. 2 , the windscreen  23  is disposed over the front cowl  22 . The windscreen  23  is supported by a windscreen stay  26 . The windscreen  23  is a vertically elongated windscreen which is greater in vertical size than in the size in a vehicle width direction. An opening  27  penetrating the windscreen  23  in a longitudinal vehicle direction (in a face-back direction of the sheet of the drawing) is provided below the center in a height direction of the vertically elongated windscreen  23 . Furthermore, the windscreen  23  has left and right cutouts  28 L and  28 R (L is a suffix representing the left, and R the right, here and hereafter) on the left and right sides of the opening  27  so that its lower portion below the center in the height direction thereof is necked. 
         [0041]    The front cowl  22  is provided with the headlight  40  in the center in the vehicle width direction, airflow inlets  29 L and  29 R on the left and right sides of the headlight  40 , and left and right turn signal lamps  31 L and  31 R at upper portions. 
         [0042]    When viewed from the vehicle front side, the turn signal lamps  31 L and  31 R overlap with grip guards  32 L and  32 R on the depth side (rearward side) thereof. 
         [0043]    As shown in  FIG. 3 , the headlight  40  includes, as main elements a housing  41 ; an adjustment plate  43  locked to pivots  42  provided on the housing  41 ; a high/low-beam reflector  45  and a high-beam reflector  46  provided on the adjustment plate  43 ; a light guide member  50  having a roughly W-shaped form and mounted to the adjustment plate  43  along edges of the reflectors  45  and  46 ; a light-blocking light cover  48  to be put on the housing  41 ; and light-transmitting lenses  49 L and  49 R formed in the light cover  48 . 
         [0044]    The high/low-beam reflector  45  and the high-beam reflector  46  are each a lower-half concave mirror obtained by removing an upper half from a concave mirror. 
         [0045]    As illustrated in  FIG. 4 , the light guide member  50  includes attachment portions  51 ; connection portions  52  (one of which is not shown) extending from the attachment portions  51 ; semicircular arched shining portions  53  extending from tips of the connection portions  52 ; and an intermediate portion  54  interconnecting the left and right shining portions  53 . 
         [0046]    In the vicinities of the attachment portions  51 , second light sources  55  are attached to the connection portions  52 . The second light sources  55  are light emitting diodes. 
         [0047]    The connection portion  52  is circular in section. The sectional shape is desirably a true circle, but may be an ellipse or an oblong. 
         [0048]    Fresnel cutting is applied to the shining portions  53 . More specifically, the shining portions  53  are cut into the shape of minute sawteeth, and the sawtooth surface serves as diffuse reflection surfaces, so that these portions shine remarkably as compared with other portions. In addition, the shining portions  53  are shaped to increase in width as the distance from the second light source  55  increases so that the width b at a central portion of the light guide member  50  is greater than the width a at both ends thereof (a&lt;b), as shown in  FIG. 3 . 
         [0049]    As depicted in  FIG. 5 , the attachment portions  51 , the connection portions  52 , and the intermediate portion (reference symbol  54  in  FIG. 4 ) are hidden by the light cover  48 . On the other hand, the left and right reflectors  45  and  46  and the left and right shining portions  53  are visible through the lenses  49 L and  49 R. 
         [0050]    In other words, the left and right reflectors  45  and  46  and the left and right lenses  49 L and  49 R are disposed on the left and right sides of a vehicle body center line  56 . In addition, the second light sources  55  are disposed respectively at the left and right ends of the light guide member  50 , which has a roughly W-shaped form. 
         [0051]    As shown in  FIG. 6 , the second light source  55  is a light emitting diode, and is integrally formed on a substrate  66 . The substrate  66  is put on the housing  41 , and the attachment portion  51  is laid on the substrate  66  so that the second light source  55  and the connection portion  52  overlap with each other. Then, the attachment portion  51  and the substrate  66  are co-fastened to the housing  41  by a screw  67 . 
         [0052]    As depicted in  FIG. 7 , a pivot bolt  57  is screwed into an upper portion of the housing  41  from the light cover  48  side. A bolt head of the pivot bolt  57  is the spherical pivot  42 , to which the adjustment plate  43  is swingably attached. 
         [0053]    As shown in  FIG. 8 , an optical axis adjustment screw  58  is attached to a lower portion of the housing  41 . The optical axis adjustment screw  58  is rotated by turning an adjustment knob  59 . The optical axis adjustment screw  58  is in screw engagement with a lower portion of the adjustment plate  43 . With the optical axis adjustment screw  58  turned, the lower portion of the adjustment plate  43  is made to advance or retract. As a result, the adjustment plate  43  is oscillated about the pivot (reference symbol  42  in  FIG. 7 ), whereby an optical axis adjustment (aiming) can be achieved. 
         [0054]    As illustrated in  FIG. 9 , the adjustment knob  59  is disposed at a lower portion in the center in the vehicle width direction of the housing  41 . A harness  61 , laid in the vicinity of the adjustment knob  59 , is positioned by a harness retainer  62  in such a position so as not to hamper turning of the adjustment knob  59 . 
         [0055]    As shown in  FIG. 10 , a first light source  63  is attached to the housing  41  at a position over the reflector  46 . The first light source  63  is a light emitting diode which emits light downward. The light is reflected by the reflector  46  to pass through the lens  49 R and travel toward the forward side of the vehicle. 
         [0056]    Since there is a vacant space on the upper side of the reflector  46 , the first light source  63  is disposed there. In addition, since there is the vacant space on the upper side of the reflector  46 , the second light source  55  is disposed there. Thus, the plurality of light sources  55  and  63  are disposed at substantially the same height, so that a power feeding system can be laid easily. 
         [0057]    As illustrated in  FIG. 11(   a ) and  FIG. 11(   b ), turning-on and turning-off of the left and right first light sources  63  and the left and right second light sources  55  are controlled by a control unit  64 . 
         [0058]    More specifically, in a high beam mode, as depicted in  FIG. 11(   a ), the left and right first light sources  63  are turned on and the second light sources  55  are turned on. As a result, the left and right reflectors  45  and  46  shine, and the light guide member  50  shines. 
         [0059]    When a low beam mode is selected, as shown in  FIG. 11(   b ), the first light source  63  on the high/low-beam reflector  45  side is turned on and the second light sources  55  are turned on, but the first light source  63  on the high-beam reflector  46  side is turned off. As a result, the left reflector  45  shines, and the light guide member  50  shines. 
         [0060]    The operation of the control unit  64  as aforementioned is merely a preferable example, and the form of turning-on/turning-off may be modified, as required. 
         [0061]    While the saddle type vehicle on which the headlight of the present invention is mounted has been a motorcycle in the aforementioned embodiment, the saddle type vehicle may be a three-wheeled vehicle or four-wheeled vehicle. 
         [0062]    While the light guide member  50  has been roughly W-shaped in the above embodiment, the shape may be modified. For example, in the case of a so-called single type headlight, a U-shape is suitable. In the case of a U-shaped light guide member, it is possible not only to provide two second light sources at both ends of the light guide member, but also to provide a second light source only at one end of the light guide member. 
         [0063]    The headlight according to the present invention is suitable for a saddle type vehicle having two wheels. 
         [0064]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.