Abstract:
A head lamp for a vehicle is provided. The headlamp includes: a reflector which reflects light emitted from a light source; a lens which the light emitted from the light source penetrates; a lens holder which supports the lens; and a shield assembly which is provided between the reflector and the lens holder.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0165693 filed in the Korean Intellectual Property Office on Dec. 27, 2013, the entire contents of which are incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a head lamp for a vehicle. 
       BACKGROUND ART 
       [0003]    In general, lamps for a vehicle are classified into a head lamp which is installed at a front side of a vehicle, and a tail lamp which is installed at a rear side of the vehicle. The head lamps are mounted at both sides of the front side of the vehicle, and allow a driver to secure a visual field in a driving direction when the vehicle is driven at night. 
         [0004]    Recently, the head lamp may be configured to be moved in up and down directions or in left and right directions depending on a driving environment. 
         [0005]    For example, in a case in which the vehicle moves along a curved road, the head lamp is rotated along the driving direction so as to help the driver to secure a visual field. 
         [0006]    Meanwhile, as illustrated in  FIG. 4 , by driving a shield  30 , which may partially block light emitted from a light source  10  of a head lamp  1 , various beam patterns may be implemented. 
         [0007]    However, a problem occurs in a case in which the shield  30  is provided inside a reflector  20 , and a shield actuator  43 , which drives the shield  30 , is provided outside the reflector  20 , or at a lens holder  50 . 
         [0008]    First, because the shield  30  and the shield actuator  43  are separately assembled, in a case in which errors, which occur during assembly processes, are accumulated, relative positions of the shield  30  and the reflector  20  deviate from each other, and as a result, optical tolerance may be excessively generated. Since the shield actuator  43  is provided outside the reflector  20 , there is a problem in that an overall size of the head lamp is increased. Shaft connection between the shield actuator  43  and the shield  30  is incorrectly performed, and thus there is a problem in that power transmission is insufficient. 
       LITERATURE OF RELATED ART  
     Patent Literature  
       [0009]    Korean Patent Application Publication No. 10-2012-0050271 (May 18, 2012) 
       SUMMARY OF THE INVENTION 
       [0010]    Embodiments of the present invention are directed to a head lamp for a vehicle, in which power transmission between a shield actuator and a shield is smoothly performed. 
         [0011]    Furthermore, the embodiments of the present invention are directed to a head lamp for a vehicle, which has a reduced size. 
         [0012]    Furthermore, the embodiments of the present invention are directed to a head lamp for a vehicle, which may reduce optical tolerance. 
         [0013]    An embodiment of the present invention provides a head lamp for a vehicle, including: a reflector which reflects light emitted from a light source; a lens which the light emitted from the light source penetrates; a lens holder which supports the lens; and a shield assembly which is provided between the reflector and the lens holder. 
         [0014]    The shield assembly may include: a shield housing which is connected to the reflector; a shield rotation shaft which is rotatably connected to the shield housing; a shield which is provided on the shield rotation shaft; and a shield actuator which rotates the shield rotation shaft. 
         [0015]    The shield actuator may include: an electric motor; and an output shaft which is connected to the electric motor, in which the output shaft is parallel to the shield rotation shaft. 
         [0016]    The output shaft may be engaged with the shield rotation shaft. 
         [0017]    A power transmission device may be provided between the output shaft and the shield rotation shaft. 
         [0018]    The power transmission device may include: a first gear which is engaged with the output shaft; and a second gear which is formed on the shield rotation shaft and engaged with the first gear. 
         [0019]    The head lamp for a vehicle may further include a first frame which accommodates the reflector, in which the shield assembly is connected to the first frame. 
         [0020]    The shield assembly may be connected to the lens holder. 
         [0021]    The first frame may include a first connecting portion, the shield assembly may include a second connecting portion, the lens holder may include a third connecting portion, and the first connecting portion may be sequentially connected to the second connecting portion and the third connecting portion. 
         [0022]    The first connecting portion may include a coupling projection, the second connecting portion may include a through hole, the third connecting portion may include an insertion groove, and the coupling projection may penetrate the through hole and may be inserted into the insertion groove. 
         [0023]    The head lamp for a vehicle may further include a second frame which accommodates the first frame, in which the first frame is rotatably connected to the second frame. 
         [0024]    The head lamp for a vehicle may further include a swivel assembly which applies rotational force to the first frame, in which the swivel assembly includes: a swivel actuator; and a swivel shaft which is connected to the swivel actuator, in which the swivel shaft penetrates the second frame and is connected to the first frame. 
         [0025]    The first frame may include a swivel shaft connecting portion that is connected to the swivel shaft, and the second frame may include a swivel shaft through hole which the swivel shaft penetrates. 
         [0026]    The head lamp for a vehicle may further include a housing which is connected to a vehicle body, in which the second frame is fixed to the housing. 
         [0027]    A maximum width of the shield assembly may be equal to or narrower than a maximum width of the reflector. 
         [0028]    According to the head lamp for a vehicle according to the embodiment of the present invention, since the shield assembly is provided inside the reflector, the shield actuator and the shield rotation shaft may be smoothly engaged with each other. 
         [0029]    According to the head lamp for a vehicle according to the embodiment of the present invention, since the shield actuator is provided inside the reflector, a size of the head lamp may be reduced. 
         [0030]    According to the head lamp for a vehicle according to the embodiment of the present invention, since the shield actuator is provided inside the reflector, relative positions of a reflection surface and a shield do not deviate from each other, thereby reducing optical tolerance. 
         [0031]    The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is an exploded perspective view illustrating a head lamp for a vehicle according to an embodiment of the present invention. 
           [0033]      FIG. 2  is a partially perspective view illustrating the head lamp of  FIG. 1 . 
           [0034]      FIG. 3  is a schematic cross-sectional view illustrating the head lamp of  FIG. 1 . 
           [0035]      FIG. 4  is an exploded perspective view illustrating a head lamp for a vehicle according to the related art. 
       
    
    
       [0036]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0037]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION 
       [0038]    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Substantially the same constituent elements are indicated by the same reference numerals in the following description and the accompanying drawings, so that a repeated description will be omitted. In describing the embodiments of the present invention, well-known related functions or configurations will not be described in detail since the detailed description for the well-known  related functions or configurations may unnecessarily obscure the understanding of the present invention. 
         [0039]    It should be understood that when one constituent element referred to as being “coupled to” or “connected to” another constituent element, one constituent element can be directly coupled to or connected to the other constituent element, but intervening elements may also be present. In contrast, when one constituent element is “directly coupled to” or “directly connected to” another constituent element, it should be understood that there are no intervening elements present. 
         [0040]    In the present specification, singular expressions include plurals unless they have definitely opposite meanings. The meaning of “comprises” and/or “comprising” used in this specification does not exclude the existence or addition of aforementioned constituent elements, steps, operations, and/or device, and one or more other constituent elements, steps, operations, and/or devices. 
         [0041]      FIG. 1  is an exploded perspective view illustrating a head lamp for a vehicle according to an embodiment of the present invention,  FIG. 2  is a partially perspective view illustrating the head lamp of  FIG. 1 , and  FIG. 3  is a schematic cross-sectional view illustrating the head lamp of  FIG. 1 . 
         [0042]    Referring to  FIGS. 1 to 3 , a head lamp for a vehicle according to an embodiment of the present invention includes a light source  100 , a reflector  200 , a lens  300 , a lens holder  400 , a shield assembly  500 , a first frame  600 , a second frame  700 , and a swivel assembly  800 . 
         [0043]    The light source  100  refers to a device which emits light, and for example, may be a light emitting diode (LED) or a halogen lamp. However, the present invention is not limited thereto, and the light source  100  may be any other device as long as the device may emit light. 
         [0044]    The reflector  200  serves to reflect light emitted from the light source  100 , and includes a light source mounting portion  210 , a side wall portion  220 , and a flange portion  230 . 
         [0045]    The light source  100  may be mounted on the light source mounting portion  210 . For example, the light source mounting portion  210  may be formed in an approximately cylindrical shape. 
         [0046]    The side wall portion  220  has a predetermined thickness, and extends from the light source mounting portion  210  so as to form an internal space  221 . A cross section of the side wall portion  220  in a lateral direction (in a Y-axis direction in the drawing) is formed in a circular shape, and a diameter of the side wall portion  220  is increased as the side wall portion  220  becomes farther away from the light source mounting portion  210  (toward an X-axis direction in the drawing). Therefore, a cross section of the side wall portion  220  in a longitudinal direction (the X-axis direction in the drawing) is formed in an approximate parabola shape. However, the present invention is not limited thereto, and the reflector may have various shapes as long as the reflector may reflect light emitted from the light source. 
         [0047]    The flange portion  230  is formed to extend at an edge of the side wall portion  220 . The flange portion  230  may include a first flange portion  231 , and a second flange portion  233 . The first flange portion  231  and the second flange portion  233  may be provided at positions opposite to each other based on a center of the internal space  221  of the side wall portion  220 . A pair of first flange portions  231  may be disposed to be symmetric to each other. Meanwhile, an edge of the second flange portion  233  may have an approximately rectangular shape. However, the present invention is not limited thereto. On the other hand, the reflector  200  may be fixed to the first frame  600  through the first flange portion  231 , and the shield assembly  500  may be fixed to the second flange portion  233 . 
         [0048]    The lens  300  allows light, which is emitted from the light source  100 , to penetrate the lens  300 . The lens  300  may be made of a general light transmissive material. The lens  300  is mounted on the lens holder  400 . 
         [0049]    The shield assembly  500  is provided between the reflector  200  and the lens holder  400 . For example, the shield assembly  500  may be formed in a shape that is accommodated in the internal space  221  of the reflector  200 . That is, a width of the shield assembly  500  may be equal to or narrower than a width of the reflector  200 . For example, as illustrated in  FIG. 3 , a maximum width W1 of the shield assembly  500  may be equal to or smaller than a maximum width W2 of the reflector  200 , that is, a length which connects both edges of the second flange portion  233 . 
         [0050]    Meanwhile, the shield assembly  500  includes a shield housing  510 , a shield rotation shaft  520 , a shield  530 , and a shield actuator  540 . 
         [0051]    The shield housing  510  forms an external shape of the shield assembly  500 . Each constituent element of the shield assembly  500  may be mounted or embedded in the shield housing  510 . 
         [0052]    The shield housing  510  may be fixed to the reflector  200 . For example, the shield housing  510  may be fixed to the second flange portion  233  of the reflector  200 . The shield housing  510  is also connected to the lens holder  400  and the first frame  600  through a third flange portion  511 , and a description thereof will be described below. 
         [0053]    The shield rotation shaft  520  is formed in a bar shape, and both ends thereof are rotatably connected to the shield housing  510 . 
         [0054]    The shield  530  is provided on the shield rotation shaft  520 . The shield  530  may have a stepped portion that is formed at an edge of the shield  530  so as to partially block light emitted from the light source  100 . Meanwhile, the shield  530  may be formed integrally with the shield rotation shaft  520 . 
         [0055]    The shield actuator  540  is a device that rotates the shield rotation shaft  520 . The shield actuator  540  includes an output shaft  541 , and an electric motor  543 . The output shaft  541  transmits rotational force to the shield rotation shaft  520 , and the electric motor  543  rotates the output shaft  541 . For example, the output shaft  541  may be parallel with the shield rotation shaft  520 . The shield actuator  540  may be controlled by an electronic control unit (not illustrated) of a vehicle. 
         [0056]    Meanwhile, a power transmission device  545  is provided between the shield rotation shaft  520  and the output shaft  541 . The power transmission device  545  includes a first gear  546 , and a second gear  547 , which are engaged with each other. The first gear  546  is engaged with the output shaft  541 , and the second gear  547  is formed on the shield rotation shaft  520 . Therefore, the rotational force of the output shaft  541  is transmitted to the shield rotation shaft  520  through the first gear  546  and the second gear  547  so as to rotate the shield rotation shaft  520 . However, the present invention is not limited thereto, and the shield rotation shaft  520  and the output shaft  541  may be directly engaged with each other. 
         [0057]    The first frame  600  includes a first main body  605 , a first connecting portion  610 , a second connecting portion  615 , and a third connecting portion  620 . 
         [0058]    The first main body  605  may be formed in a hollow shape so as to accommodate the reflector  200 . 
         [0059]    The first connecting portion  610  extends from the first main body  605 , and is connected to the shield assembly  500  and the lens holder  400 . A coupling projection  611  may be provided on the first connecting portion  610 . 
         [0060]    Meanwhile, the shield assembly  500  includes the third flange portion  511  that extends from the shield housing  510 , and a through hole  513  is formed in the third flange portion  511 . On the other hand, an insertion groove  411  is formed in a fourth flange portion  410  that extends from the lens holder  400 . 
         [0061]    Therefore, the coupling projection  611  of the first connecting portion  610  penetrates the through hole  513  of the third flange portion  511 , and is inserted into the insertion groove  411  of the fourth flange portion  410 , such that the first frame  600 , the shield assembly  500 , and the lens holder  400  may be connected. 
         [0062]    On the other hand, the first connecting portion  610  is rotatably connected to the second frame  700 . A description thereof will be described below. 
         [0063]    Meanwhile, the second connecting portion  615  is a portion to which the first flange portion  231  of the reflector  200  is fixed. That is, the first flange portion  231  is fixed to the second connecting portion  615  while the reflector  200  is accommodated in the first main body  605 , such that the reflector  200  may be fixed to the first frame  600 . 
         [0064]    The third connecting portion  620  extends from the first main body  605  at a position opposite to the first connecting portion  610 . The first frame  600  is rotatably connected to the second frame  700  through the third connecting portion  620 . A description thereof will be described below. 
         [0065]    The second frame  700  includes a second main body  705 , a fourth connecting portion  710 , and a fifth connecting portion  715 . 
         [0066]    The second main body  705  may be formed in a hollow shape so as to accommodate the first frame  600 . 
         [0067]    The fourth connecting portion  710  and the fifth connecting portion  715  extend from the second main body  705  at positions opposite to each other. The first frame  600  is rotatably connected to the second frame  700  through the fourth connecting portion  710  and the fifth connecting portion  715 . Specifically, the fourth connecting portion  710  is connected to the first connecting portion  610  of the first frame  600 , and the fifth connecting portion  715  is connected to the third connecting portion  620 . 
         [0068]    The relative rotation of the first frame  600  with respect to the second frame  700  refers to swiveling, and this may be performed by the swivel assembly  800 . The swivel assembly  800  includes a swivel shaft  810 , and a swivel actuator  820 . The swivel shaft  810  is a rotatable power transmission shaft, and the swivel actuator  820  rotates the swivel shaft  810 . The swivel actuator  820  may include an electric motor (not illustrated). 
         [0069]    A swivel shaft through hole  711  is provided in the fourth connecting portion  710 , and a swivel shaft connecting portion  613  is provided on the first connecting portion  610  of the first frame  600 . The swivel shaft  810  may penetrate the swivel shaft through hole  711 , and be connected to the swivel shaft connecting portion  613 . When the swivel actuator  820  is driven and the swivel shaft  810  is rotated, rotational force is transmitted to the swivel shaft connecting portion  613 . Since the swivel shaft connecting portion  613  may be rotated in the swivel shaft through hole  711 , the first frame  600  may be relatively rotated with respect to the second frame  700 . 
         [0070]    A first pin insertion hole  716  is provided in the fifth connecting portion  715 , and a second pin insertion hole  621  is provided in the third connecting portion  620  of the first frame  600 . The fifth connecting portion  715  and the third connecting portion  620  may be rotatably connected by a connecting pin  623  that simultaneously penetrates the first pin insertion hole  716  and the second pin insertion hole  621 . 
         [0071]    As described above, the first frame  600  and the second frame  700  are rotatably connected at two positions. That is, the swivel shaft connecting portion  613  of the first frame  600  is inserted into the swivel shaft through hole  711  of the second frame  700 , and the third connecting portion  620  of the first frame  600  is connected to the fifth connecting portion  715  of the second frame  700 . 
         [0072]    However, if rotation axes do not coincide with each other at the two positions, the relative rotation of the first frame  600  and the second frame  700  is not smoothly performed, and related constituent components may be damaged. Therefore, the rotation axes need to coincide with each other at the two positions. That is, the first pin insertion hole  716 , the second pin insertion hole  621 , the swivel shaft through hole  711 , the swivel shaft connecting portion  613 , and the swivel shaft  810  are present on a straight line. 
         [0073]    Meanwhile, the second frame  700  may be fixed to a housing (not illustrated). The housing is connected to a vehicle body, and therefore, the second frame  700  is fixed unlike the first frame  600  that is rotatable. 
         [0074]    As described above, according to the embodiment of the present invention, the shield assembly  500  is provided between the reflector  200  and the lens holder  400 , that is, inside the reflector  200 . In other words, the shield  530  and the shield actuator  540  are provided together inside the reflector  200 . As such, since the shield actuator  540  is provided inside the reflector  200 , a space may be saved, and an overall size of the head lamp may be reduced. 
         [0075]    According to the present embodiment, since the shield rotation shaft  520  and the shield actuator  540  are provided together inside the reflector  200 , shaft connection is accurately performed, such that power transmission may be smoothly performed. According to the present embodiment, since the shield rotation shaft  520  and the shield actuator  540  are simultaneously assembled to form the shield assembly  500 , an error may be reduced during an assembly process, and optical tolerance may also be reduced. 
         [0076]    As described above, the embodiments have been described and illustrated in the drawings and the specification. The embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various embodiments of the present invention, as well as various alternatives and modifications thereof. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.