Abstract:
A sunroof apparatus for use in an automotive vehicle having a roof with an opening portion includes a movable panel, a supporting mechanism supporting the movable panel, an actuating device generating an actuating force for actuating the movable panel, a transmitting mechanism transmitting the actuating force, the transmitting mechanism having a rack belt made of resin and engaging with an actuating gear of the actuating device and a guiding member guiding the rack belt so as to be slidable, wherein the rack belt includes a plurality of longitudinally disposed and alternately spaced rack teeth and grooves, each of the grooves being provided with a protruding portion bridging two adjacent rack teeth at a mid portion of each groove, and a core wire embedded within the protruding portion of the rack belt so as to extend in a longitudinal direction of the rack belt.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application 2006-029837, filed on Feb. 7, 2006, the entire content of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a sunroof apparatus. Specifically, the present invention relates to a configuration of a rack belt serving as means for transmitting an actuating force. 
       BACKGROUND 
       [0003]    A known sunroof apparatus, which actuates a movable panel so that an opening portion provided at a roof of a vehicle is opened/closed, includes an actuating device and a transmitting mechanism for transmitting an actuating force generated by the actuating device to a supporting mechanism of the movable panel. 
         [0004]    More specifically, a sunroof apparatus disclosed in JP2001-130261A includes a geared cable used as the transmitting mechanism. The geared cable includes a cable portion and a gear portion, both of which are made of metal. The gear portion is provided continuously on the outer peripheral surface of the geared cable so as to extend spirally in a longitudinal direction thereof. The geared cable is guided by and within a metal guide having a circular cross section. 
         [0005]    Further, another transmitting mechanism, for example, a roof apparatus disclosed in JP2002-154328A includes a rack belt instead of the geared cable. Such rack belt is made of resin in order to achieve weight saving and quietness in its actuation. 
         [0006]    The geared cable disclosed in JP2001-130261A is flexible in any directions and has a tensile strength. The geared cable further includes strength at the gear portion thereof. Therefore, such geared cable has high endurances and is easy to attach to the sunroof apparatus. 
         [0007]    On the other hand, the transmitting mechanism using a rack belt made of resin and disclosed in JP2002-154328A is lighter than the geared cable. Further, by use of such transmitting mechanism, quietness in its actuation can be obtained. In actual usage, in order to obtain a high tensile strength, a reinforcement member, such as a wire made of steel, may be embedded within the rack belt. However, because of such wire serving as a reinforcement member, it may be difficult to bend the rack belt depending on the position of the wire in the rack belt. Further, the rack belt is attached to the sunroof apparatus in a manner where it is slidably housed within the guide. In this configuration, because of the flexibility of the rack belt, frictional resistance occurring between the rack belt and the guide at a position where the guiding member together with the rack belt is bent may be increased, as a result, transmitting efficiency may be reduced. 
         [0008]    For example, as illustrated in  FIG. 2 , a guiding member  28   a , extending leftward from a central portion facing forward, crosses over a guiding member  27   b  at a position A, and then the guiding member  28   a  is bent upward. Further, at the point B where each guiding member extending in a front-rear direction toward the side of the guiding rail from the side of the housing  16 , which is extending in a horizontal direction, the each guiding member is bended in a horizontal direction. 
         [0009]    A need thus exists to provide a rack belt made of resin, which obtains a required strength so as to be capable of being a transmitting mechanism and is flexible in an upward and downward direction and a horizontal direction without increasing friction resistance. 
       SUMMARY OF THE INVENTION 
       [0010]    According to an aspect of the present invention, a sunroof apparatus for use in an automotive vehicle having a roof with an opening portion includes a movable panel opening and closing the opening portion formed on the roof of the automotive vehicle, a supporting mechanism supporting the movable panel movably relative to the roof, an actuating device generating an actuating force for actuating the movable panel, a transmitting mechanism transmitting the actuating force generated by the actuating device, the transmitting mechanism having a rack belt made of resin and engaging with an actuating gear of the actuating device and a guiding member guiding the rack belt so as to be slidable, wherein the rack belt includes a plurality of longitudinally disposed and alternately spaced rack teeth and grooves, each of the grooves being provided with a protruding portion bridging two adjacent rack teeth at a mid portion of each groove, and a core wire embedded within the protruding portion of the rack belt so as to extend in a longitudinal direction of the rack belt. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawings, wherein: 
           [0012]      FIG. 1  illustrates a flat view indicating a sunroof apparatus of the present invention attached to a roof of a vehicle; 
           [0013]      FIG. 2  illustrates an exploded perspective view indicating a front portion of the sunroof apparatus; 
           [0014]      FIG. 3  illustrates an exploded perspective view indicating a supporting mechanism of the sunroof apparatus; 
           [0015]      FIG. 4  illustrates an oblique perspective view indicating a state in which an actuating device is attached to the sunroof apparatus according to a first embodiment of the present invention; 
           [0016]      FIG. 5  illustrates a cross sectional view indicating the actuating device the sunroof apparatus according to the first embodiment of the present invention; 
           [0017]      FIG. 6  illustrates an oblique perspective view indicating a meshing state between rack belts and an actuating gear according to the first embodiment of the present invention; 
           [0018]      FIG. 7  illustrates a cross sectional view of the transmitting mechanism along a VII-VII line in  FIG. 2  according to the first embodiment of the present invention; and 
           [0019]      FIG. 8  illustrates a cross sectional view indicating a transmitting mechanism of a sunroof apparatus according to a second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    A first embodiment of a sunroof apparatus  10  related to the present invention will be explained in accordance with the attached drawings. 
         [0021]      FIG. 1  illustrates a top view indicating the sunroof apparatus  10  attached to a roof  11  of a vehicle  1 .  FIG. 2  illustrates an exploded perspective view indicating a front portion of the sunroof apparatus  10 . 
         [0022]    Each direction indicated by arrows in the drawings represents a front direction, a left direction and a right direction relative to the vehicle  1 . Because the sunroof apparatus  10  basically has a symmetric structure in a right-left direction of the vehicle  1 , identical numerals are used in each right and left side of the sunroof apparatus  10 , and different numbers are used only when there is a need to explain a difference in the configurations between the left side and the right side. 
         [0023]    An opening portion  13  indicated by a chain double-dashed line in  FIG. 1  is provided on the roof  11  of the vehicle  1 . A pair of guiding rails  14  is provided at the opening portion  13 , specifically, one guiding rail  14  (right guiding rail  14 ) is provided at the right edge of the opening portion  13 , and the other guiding rail  14  (left guiding rail  14 ) is provided at the left edge of the opening portion  13 , and each of them is provided so as to extend in a front-rear direction of the vehicle  1 . Further, a housing  16  is provided along a front edge of the opening portion  13  so as to extend in a right-left direction of the vehicle  1 , and a right end of the housing  16  is connected to a front end of the right guiding rail  14 , and a left end of the housing  16  is connected to a front end of the left guiding rail  14 . 
         [0024]    The sunroof apparatus  10  is fixed to an under surface of the roof  11  by means of each guiding rail  14  and the housing  16 . Further, the right guiding rail  14  is connected to the left guiding rail  14  by means of a supporting member  17  at a rearward portion of the sunroof apparatus  10  relative to a rear end of the opening portion  13 . Therefore, as illustrated in  FIG. 1 , the sunroof apparatus  10  is also fixed to the under surface of the roof  11  by means of the supporting member  17 . 
         [0025]    At each guiding rail  14 , a supporting mechanism  20  for supporting the movable panel  18  from below thereof is attached. As illustrated in an exploded perspective view in  FIG. 3 , the supporting mechanism  20  includes a link member  21  and a shoe member  23 . Each of the link member  21  and the shoe member  23  is supported by each guiding rail  14  so as to be slidable in a front-rear direction of the vehicle  1 . Further, a pair of projecting portions  23   b  is formed at the shoe member  23  so as to be engageable with a pair of guiding grooves  21   a  formed at the link member  21 . In  FIG. 3 , only one guiding groove  21   a  is illustrated. Because the projecting portions  23   b  are positioned relative to the guiding groove  21   a  in this manner, when the shoe member  23  is positioned at a predetermined position relative to the guiding rail  14 , the movement of the link member  21  in a front-rear direction and a tilt of the link member  21  in an upper and lower direction are regulated, and further, the movable panel  18  fixed to the link member  21  is moved in a front-rear direction or tilted, so as to close and open the opening portion  13 . 
         [0026]    Furthermore, as illustrated in  FIG. 3 , plural detent portions  23   a  are formed at the shoe member  23 . At the left side of the vehicle, a rack belt  32  is attached to the left guiding rail  14  so as to be movable in a front-rear direction. The shoe member  23  is connected to the rack belt  32  in a manner where the detent portions  23   a  of the shoe member  23  fit plural recessed portions  33  formed on upper and lower surfaces of the rack belt  32  at a rear end in a longitudinal direction thereof. On the other hand, at the right side of the vehicle, a rack belt  31  is attached to the right guiding rail  14  so as to be movable in a front-rear direction. The shoe member  23  is connected to the rack belt  31  in a manner where the detent portions  23   a  of the shoe member  23  fit plural recessed portions  33  formed on upper and lower surfaces of the rack belt  31  at a rear end in a longitudinal direction thereof. The transmitting mechanism  26  is comprised of the rack belt  32 , guiding members  28   a  and  28   b , and the transmitting mechanism  25  is comprised of the rack belt  31 , guiding members  27   a  and  27   b . Each guiding member will be described in detail below. 
         [0027]    As illustrated in  FIG. 2  and  FIG. 4 , at a front end of the right guiding rail  14 , the guiding member  27   a  is connected at one end thereof. The guiding member  27   a  is bent so as to extend in a width direction of the vehicle along the housing  16 , and then the guiding member  27   a  is attached to a right half portion of the housing  16  by means of engaging portions  16   a ,  16   b  and  16   c , which are integrally formed at the right half portion of the housing  16 . As illustrated in  FIG. 4 , a supporting base portion  16   d , to which an actuating device  50  described later is attached, is formed at the housing  16 , and the other end of the guiding member  27   a  is attached to a right portion of the supporting base portion  16   d . The guiding member  27   b  is attached to a left portion of the supporting base portion  16   d  in a manner where one end of the guiding member  27   b  faces the other end of the guiding member  27   a  attached to the right portion of the supporting base portion  16   d . In the same manner as the right half portion of the housing  16 , the guiding member  27   b  is attached to a left half portion of the housing  16  by means of engaging portions  16   a ,  16   b  and  16   c , which are formed at the left half portion of the housing  16 . Further, the other end of the guiding member  27   b  is bent so as to correspond a side surface of the left guiding rail  14  and engaged therewith so as not to be affected by vibrations and the like. 
         [0028]    The right rack belt  31  extends from the right shoe member  23  forward within the right guiding rails  14 , and penetrates through the guiding member  27   a . Further, the right rack belt  31  penetrates through the guiding member  27   b  and attached to the left guide rail  14 . The length of the guiding member  27   b  is set in a manner where, when the shoe member  23  is moved foremost, the end of the rack belt  31  is not exposed to outside of the other end of guiding member  27   b.    
         [0029]    In the same manner as the right rack belt  31 , the left rack belt  31  extends from the left shoe member  23  and attached to the right guide rail  14 . In this way, the transmitting mechanism  25  is comprised of a combination of the guiding member  27   a  and the guiding member  27   b , the transmitting mechanism  26  is comprised of a combination of the guiding member  28   a  and the guiding member  28   b.    
         [0030]    A configuration of the actuating device  50  will be explained in accordance with  FIGS. 4 ,  5  and  6 . 
         [0031]    As mentioned above, the actuating device  50  is attached to the supporting based portion  16   d , which is formed at the housing  16  at a central portion in a right-left direction thereof. The actuating device  50  includes a motor  51  for providing actuating force, a wheel  52  and a drive shaft  53 . The actuating force generated by the motor  51  is transmitted to the wheel  52  in order to rotate the drive shaft  53  of the drive shaft provided so as to be integral to the wheel  52 . A serration  53   a  comprised of plural grooves is formed at an outer peripheral surface of the drive shaft  53 , and an actuating gear  56  is attached to the drive shaft  53  so as to be rotated integrally therewith. Specifically, the actuating gear  56  has a hole  55  at which a female serration  55   a  to be meshed with the serration  53   a  is formed. Further, teeth  57  are formed at an outer peripheral surface of the actuating gear  56 . 
         [0032]    As illustrated in  FIGS. 4 ,  5  and  6 , each rack belt  31  and  32  has rack teeth  35  including rack grooves  35   a , and the rack belts  31  and  32  are provided in a manner where the actuating gear  56  is sandwiched therebetween, and the teeth  57  of the actuating gear  56  meshes the rack teeth  35  of each rack belt  31  and  32 . In this configuration, the rack belts  31  and  32  are simultaneously actuated. Thus, the teeth  57  of the actuating gear  56  meshes the rack teeth  35  of each rack belt  31  and  32  so that the actuating force is transmitted to each rack belt  31  and  32 . In this configuration, because each rack belt  31  and  32  is moved by the rotation of the actuating gear  56 , the shoe members  23  attached to the rack belt  31  and the shoe member  23  attached to the rack belt  32  are simultaneously moved in the same direction. 
         [0033]    In accordance with  FIGS. 5 and 6 , a configuration of each rack belt  31  and  32  related to the present invention will be further explained. 
         [0034]    In  FIG. 6 , a width of the rack teeth  35  of each rack belt  31  and  32  in a tooth trace direction is indicated by a width H. At a central portion of each rack belt  31  and  32  in the direction of the width H, a core wire  37  is embedded so as to extend in a longitudinal direction and within an entire length of each rack belt  31  and  32 . When each rack belt  31  and  32 , made of resin, is molded, the core wire  37  is embedded at a predetermined position by means of, for example, extrusion so as to be integral with each rack belt  31  and  32 . In this method, production costs of the rack belt become less expensive. Further, in this embodiment, because a single core wire is embedded at the central portion of the width H of each rack belt  31  and  32 , a flexibility of the resin rack belt  31  and  32  in any direction can be maintained at same level of a resin belt without a core wire. 
         [0035]    Further, as illustrated in  FIG. 7 , protruding portions  78  is formed at each rack belt  31  and  32 . Specifically, each protruding portion  78  is formed in a manner where a thickness thereof relative to the core wire  37  in its cross section becomes a thickness “t” indicated in  FIG. 7 . Each protruding portion  78  is formed at the central portion of each rack groove  35   a  so as to bridge between one of the rack teeth  35  and the other of the rack teeth  35 , which is formed next to the one of the rack teeth  35 , as illustrated in  FIG. 6 . In this configuration, as illustrated in  FIG. 7 , a thickness “I” of each rack belt  31  and  32  is reduced as far as possible so that the costs thereof are reduced. Because the thickness “I” of each rack belt  31  and  32  is reduced, flexibility thereof in a horizontal direction is also obtained. Further, because the protruding portion  78  is formed and provided so as to bridge between one of the rack teeth  53  and the other of the rack teeth  53  at a central portion thereof as mention above, a strength of the rack teeth  35  can be enhanced, as a result, the size of each teeth of the rack teeth  53  can be reduced, and a meshing pitch between each rack belt  31  and  32  and the actuating gear  56  can be reduced. Thus, positional adjustment of the movable panel  18 , in other words, installation adjustment of the movable panel  18  becomes easier. 
         [0036]    Furthermore, on each of the teeth  57  of the actuating gear  56 , a recessed portion  57   a  is formed as illustrated in  FIG. 6 . Thus, when the actuating gear  56  meshes each of rack belts  31  and  32 , because the recessed portion  57   a  is formed at each of the teeth  57 , the each of the teeth  57  does not interfere with the protruding portion  78  formed at each rack belt  31  and  32 . In this configuration, the teeth  57  of the actuating gear  56  mesh the rack groove  35   a  at meshing portions  57   b  of the teeth  57  as illustrated in  FIG. 6 . In this embodiment, two meshing portions  57   b  are formed on each of the teeth  57   a , and one meshing portion  57   b  is formed at the upper side relative to the recessed portion  57   a , and the other meshing portion  57   b  is formed at the lower side relative to the recessed portion  57   a  as illustrated in  FIG. 6 . Because of the recessed portion  57   a  meshing the protruding portion  78 , the actuating gear  56  can mesh each rack belt  31  and  32  precisely. 
         [0037]    In this configuration, according to the sunroof apparatus  10  of the present invention, as illustrated in  FIG. 2 , the guiding member  28   a  extending leftward crosses with the guiding member  27   b  at a position A, and at this position, the guiding member  28   a  is bended upward. Further, at the point B where each guiding member  28   a  and  27   b  extending in a front-rear direction toward the side of the guiding rail  14  from the side of the housing  16 , which is extending in a horizontal direction, the each guiding member is bended in a horizontal direction. In this configuration, because each rack belt  31  and  32  is flexible, actuation force can be effectively transmitted by means of each rack belt  31  and  32 , without enhancing sliding resistance at the positions A and B. 
         [0038]    A second embodiment related to the present invention will be explained in accordance with  FIG. 8 . 
         [0039]    In the second embodiment, a guiding member  127  for guiding the rack belt  31  is made of a pipe including a hollow portion having a circular cross section. The rack belt  131  slides with contacting with an inner peripheral surface of the hollow portion of the guiding member  127  at three portions, each upper and lower surface of the rock teeth  135  and a contacting protruding portion  131   a  formed at a back surface of the rock teeth  135 . A core wire  137  is embedded at a central portion of the rack belt  131 . Specifically, the core wire  137  is embedded at the rack belt  131  at a position being identical with a center of the internal diameter of the guiding member  127 . In the second embodiment, because of the existence of the contacting protruding portion  131   a , stiffness in a vertical direction can be enhanced relative to the rack belt in the first embodiment. Further, when the guiding member  127  is made of an existing pipe material made of metal, an accurate internal diameter can be obtained, and the costs thereof can be reduced. 
         [0040]    In the second embodiment, a guiding member  127  for guiding the rack belt  31  is made of a pipe including a hollow portion having a circular cross section. The rack belt  131  slides with contacting with an inner peripheral surface of the hollow portion of the guiding member  127  at three portions, each upper and lower surface of the rock teeth  135  and a contacting protruding portion  131   a  formed at a back surface of the rock teeth  135 . A core wire  137  is embedded at a central portion of the rack belt  131 . Specifically, the core wire  137  is embedded at the rack belt  131  at a position being identical with a center of the internal diameter of the guiding member  127 . In the second embodiment, because of the existence of the contacting protruding portion  131   a , stiffness in a vertical direction can be enhanced relative to the rack belt in the first embodiment. Further, when the guiding member  127  is made of an existing pipe material made of metal, an accurate internal diameter can be obtained, and the costs thereof can be reduced. 
         [0041]    Thus, because the core wire is embedded in the rack belt in a manner where it extends in a longitudinal direction thereof, a required tensile strength of the rack belt for transmitting the actuating force is obtained. In this configuration, the core wire is penetrated through the protruding portions provided at the central portion in a tooth trace direction of each rack groove of the rack teeth. Thus, even when the rack belt is bent in a vertical or a horizontal direction, a tensile force or a compressive force applied to the core wire can be reduced, and a flexibility being approximately equal to that of a rack belt made of resin without a core wire is obtained. Further, because of this flexibility, resistance of the rack belt at a portion thereof at which it is bent in order to be attached to the sunroof apparatus can be reduced. 
         [0042]    Further, strength of the rack teeth is enhanced because of the protruding portion formed at the rack groove provided at the rack teeth. 
         [0043]    Such the guiding member may be made of an existing pipe material made of metal, an accurate internal diameter can be obtained, and the costs thereof can be reduced. Thus, the transmitting mechanism having such guiding member is easy to be attached to the sunroof apparatus, and its resistance can be reduced. 
         [0044]    The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the sprit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.