Abstract:
A roller sunshade device suppressing the drooping of both end portions in a width direction of a shad. The roller sunshade device includes an extendable and retractable shade, and a tension providing unit providing greater tension to both end portions in the width direction of the shade than to a center portion thereof. The roller sunshade device also includes a handle member including a support portion supporting a distal end portion of the shade, wherein at least one of the support portion of the handle member and the distal end portion of the shade is curved prior to assembly thereof, and when the distal end portion of the shade is assembled to the support portion of the handle member, greater tension is provided to the both end portions in the width direction of the shade than to the center portion thereof.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a roller sunshade device provided to a roof of a vehicle. 
       BACKGROUND ART 
       [0002]    There is known a roller sunshade device that lets in or blocks out light through a compartment opening provided to a fixed roof of a vehicle. For example, Patent Literature 1 describes a conventionally known structure of such a roller sunshade device. The roller sunshade device of Patent Literature 1 has left and right guide rails provided on the respective sides of a roof opening, a shade that opens or closes the roof opening, a retractor that rolls up the shade, and a handle member which is attached to a tip end portion of the shade and is slidable along the left and right guide rails. The handle member has a support portion formed at its rear end to support the tip end portion of the shade across the width thereof. 
         [0003]    A roll-up spring provided in the retractor causes predetermined tensile forces to act on the shade in a roll-up direction. These tensile forces prevent the shade from slackening (sagging). In the conventional roller sunshade device, the tip end portion of the shade and the support portion of the handle are both formed linearly in the width direction. 
       CITATION LIST 
     Patent Literature 
       [0004]    Patent Literature 1: Japanese Patent Application Publication No. 2011-079437 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]      FIG. 6  is a perspective view of a conventional roller sunshade device. As shown in  FIG. 6 , when an opening A 1  of a roof A is closed with a shade  30  of the conventional roller sunshade device, widthwise end portions  32 A of the shade  30  may slacken at a center portion in a front-rear direction of the shade  30 . The slackening is thought to occur because, although the retractor  5  causes the predetermined tensile forces to act on the shade  30 , it is difficult for the tensile forces to act on the widthwise end portions  32 A of the shade  30 . 
         [0006]    A conceivable countermeasure against the above problem is, for example, to support the widthwise end portions  32 A of the shade  30  on left and right guide rails  4 ,  4 . This may, however, complicate the structure, increase the number of components, and furthermore, lower operability as a result of increased resistance against unrolling and rolling-up operations. 
         [0007]    The present invention has been created to solve such problems, and has an object to provide a roller sunshade device capable of advantageously preventing a shade from slackening at widthwise end portions thereof. 
       Solution to Problem 
       [0008]    To solve the foregoing problems, a roller sunshade device of the present invention includes a stretchable shade and a tensile force application part that applies a larger tensile force to widthwise end portions of the shade than to a widthwise center portion of the shade. 
         [0009]    According to the above configuration, the widthwise end portions of the shade are pulled in an unroll direction more strongly than the widthwise center portion of the shade because a larger tensile force is applied to the end portions than to the center portion. This can advantageously prevent the shade from slackening at the widthwise end portions thereof. 
         [0010]    Preferably, the roller sunshade device includes a handle member having a support portion that supports a tip end portion of the shade, and the tensile force application part is configured such that: at least one of the support portion of the handle member and the tip end portion of the shade forms a curve in a pre-assembled state; and when the tip end portion of the shade is assembled to the support portion of the handle member, a larger tensile force is applied to the widthwise end portions of the shade than to the widthwise center portion of the shade. 
         [0011]    According to the above configuration, the tensile force application part can have a simple structure because it is only necessary to form either one of the support portion of the handle member and the tip end portion of the shade into a curved shape. Thus, the prevention of slackening of the shade can be achieved without complicating the structure, increasing the number of components, or lowering operability as a result of increased resistance against unrolling and rolling-up operations. 
         [0012]    Preferably, the tip end portion of the shade includes an accommodation portion formed by folding back and sewing an edge, and a core material inserted into the accommodation portion. 
         [0013]    According to the above configuration, the tip end portion of the shade can advantageously maintain its state of being assembled to the handle member even though the widthwise end portions of the shade are pulled in the unroll direction more strongly than the widthwise center portion of the shade. 
       Advantageous Effects of Invention 
       [0014]    The roller sunshade device of the present invention can advantageously prevent the shade from slackening at the widthwise end portions thereof. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0015]      FIGS. 1A and 1B  are diagrams showing a roller sunshade device according to an embodiment of the present invention,  FIG. 1A  being a schematic perspective view and  FIG. 1B  schematically showing, with a grid, how a shade stretches. 
           [0016]      FIG. 2A  is a plan view showing the shade and a handle member,  FIG. 2B  is a sectional view showing the shade and a retractor, and  FIG. 2C  is a sectional view showing how the shade is supported by the handle member. 
           [0017]      FIG. 3  is a plan view showing the magnitudes of tensile forces acting on the shade. 
           [0018]      FIG. 4A  is a plan view showing a shade and a handle member according to a modification, and  FIG. 4B  is a plan view showing the magnitudes of tensile forces acting on the shade. 
           [0019]      FIGS. 5A and 5B  are plan views showing shades and handle members according other modifications. 
           [0020]      FIG. 6  is a perspective view showing a conventional roller sunshade device. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0021]    An embodiment of a roller sunshade device according to the present invention is described hereinbelow with reference to the drawings. Note that directions referred to in the following description as “front”, “rear”, “left”, “right”, “up”, and “down” are based on the directions shown in  FIG. 1 . Furthermore, a front-rear direction herein corresponds to forward and backward directions in which a vehicle travels. 
         [0022]    A roller sunshade device  1  of the present embodiment is, as shown in  FIGS. 1A and 1B , a device that lets in or blocks out light through an opening portion A 1  formed in a roof A of a vehicle (not shown) and surrounded by a frame body  2 . The roller sunshade device  1  can open and close the opening portion A 1  of the roof A by sliding a shade  3 , placed at the opening portion A 1 , in the front-rear direction. For example, a glass plate is fitted in the roof A to allow light in. 
         [0023]    The roller sunshade device  1  includes guide rails  4 ,  4  provided respectively on left and right side portions of the opening portion A 1  of the vehicle, the shade  3  configured to cover the opening portion A 1 , and a retractor  5  placed inside the frame body  2  on a rear side thereof and configured to roll up the shade  3 . A handle member  6  is attached to a tip end portion  3   a  of the shade  3 . A rear end portion  3   b  of the shade  3  (see  FIG. 2B ) is fixed to an outer circumferential surface of the retractor  5 . Widthwise end portions of the handle member  6  are provided with sliders (not shown). The sliders are supported by the left and right guide rails  4 ,  4 , respectively. 
         [0024]    The retractor  5  includes a roll-up spring (not shown). The roll-up spring causes predetermined tensile forces to act on the shade  3  in a roll-up direction. 
         [0025]    In the roller sunshade device  1 , the shade  3  slides along the left and right guide rails  4 ,  4  in the front-rear direction, getting unrolled from the retractor  5  or rolled up by the retractor  5 . 
         [0026]    The roller sunshade device  1  may be provided with a driving device for rolling up and unrolling the shade  3 . In this case, for example, the driving device is configured to drive a driving motor (not shown) to rotate forward or backward so that a cable fixed to the handle member  6  moves frontward or rearward along the guide rails  4 ,  4 , causing the shade  3  to be unrolled from the retractor  5  or rolled up by the retractor  5 . 
         [0027]    The left and right guide rails  4 ,  4  are placed along the left and right side portions of the frame body  2 , respectively, at positions between, for example, the vehicle&#39;s compartment ceiling (not shown) and an outer plate of the roof of the vehicle. The left and right guide rails  4 ,  4  are formed to be symmetric to each other and extend in the front-rear direction. The guide rails  4 ,  4  are formed from a material for extrusion molding, e.g., an aluminum alloy. 
         [0028]    A rail groove  4   a  is formed on an inner side surface of each guide rail  4 . The sliders (not shown) provided to side portions of the handle member  6  are slidably inserted into the respective rail grooves  4   a . The sliders are slidable in the front-rear direction by being guided by the rail grooves  4   a.    
         [0029]    The shade  3  is formed from a stretchable fabric body. As shown in  FIG. 2A , the tip end portion  3   a  of the shade  3  forms a curve having a predetermined radius of curvature R in such a manner that a widthwise (left-right direction) center portion  31  of the shade  3  protrudes in an unroll direction (frontward) relative to widthwise end portions  32 ,  32 . Thereby, a length L 2  of the shade  3  from an axis of the retractor  5  to a tip end of each end portion  32  is shorter than a length L 1  of the shade  3  from the axis O 1  of the retractor  5  to a tip end of the center portion  31 . 
         [0030]    As shown in  FIG. 2B , the tip end portion  3   a  of the shade  3 , which forms the aforementioned curve having the radius of curvature R, has its edge made into a tubular shape by being folded back, sewn, and distended. An accommodation portion  3   c  is formed inside the distended tubular portion. A solid-cylindrical core material  33  made of a metal or resin is inserted into the accommodation portion  3   c . The core material  33  is long enough to be inserted through substantially the entire accommodation portion  3   c  in the width direction. The outer diameter of the core material  33  is larger than an opening dimension of an opening  6   d   2  to be described later. The shape of the core material  33  before being inserted into the accommodation portion  3   c  is linear in the present embodiment, but may be curved instead. 
         [0031]    As shown in  FIG. 2A , the handle member  6  extends in the width direction of the shade  3  and curves upward with its widthwise center being situated highest. The handle member  6  has a support portion  6   d  formed at a rear portion thereof, the support portion  6   d  extending linearly in the width direction. As shown in  FIG. 2C , the support portion  6   d  is shaped substantially like the letter C in a side view, and has an opening  6   d   1  (see  FIG. 2A ) which opens to each side and the opening  6   d   2  which opens to the rear and extends in the width direction. The tip end portion  3   a  having the core material  33  inserted therein can be put inside the support portion  6   d  through the opening  6   d   1  and the opening  6   d   2  at the rear end. In other words, the support portion  6   d  is capable of accommodating the tip end portion  3   a  having the core material  33  inserted therein, and serves to hold the tip end portion  3   a  so that the tip end portion  3   a  will not come off rearward. 
         [0032]    As shown in  FIG. 2C , the handle member  6  is formed by assembly of an upper member  6   b  onto a lower member  6   a . A finger-placement indentation portion  6   c  is opened and formed in a lower surface of the lower member  6   a  so that a user can insert and place their finger for operation. The upper member  6   b  is assembled to the lower member  6   a  in such a manner as to cover the finger-placement indentation portion  6   c  from above. The aforementioned support portion  6   d  is integrally provided to a rear end portion of the upper member  6   b.    
         [0033]    In the roller sunshade device  1  thus configured, to connect the shade  3  to the handle member  6 , the linear core material  33  is inserted into the accommodation portion  3   c  of the shade  3 , and then, as shown in  FIG. 2C , the accommodation portion  3   c  and the core material  33  are inserted into the support portion  6   d  through the opening  6   d   1  of the support portion  6   d  (see  FIG. 2A ). Alternatively, the tip end portion  3   a  of the shade  3  may be put inside the support portion  6   d  of the handle member  6  first, and then the core material  33  may be inserted into the accommodation portion  3   c  of the tip end portion  3   a  from the opening  6   d   1  of the support portion  6   d . Thereby, the core material  33  allows the tip end portion  3   a  of the shade  3  to be supported in, and not to come off from, the support portion  6   d  of the handle member  6 . The shade  3  curves upward in conformity with the shape of the handle member  6 . 
         [0034]    As shown in  FIG. 2A , since the tip end portion  3   a  of the shade  3  has the radius of curvature R, the length L 2  from the axis O 1  of the retractor  5  to the tip end of each end portion  32  is shorter than the length L 1  from the axis O 1  of the retractor  5  to the tip end of the center portion  31 . Thus, the center portion  31  and each widthwise end portion  32  differ in length by a length L 3 , which is a length obtained by subtraction of L 2  from L 1 . When the curved tip end portion  3   a  is supported by the support portion  6   d  of the handle member  6  which is linear in the width direction, as shown in  FIG. 3 , the widthwise end portions  32 ,  32  of the shade  3  are pulled in the front-rear direction more strongly than the widthwise center portion  31  of the shade  3 . This can advantageously prevent the shade  3  from slackening at the widthwise end portions  32 ,  32 , or more specifically, center portions of the end portions  32 ,  32  in the front-rear direction (see  FIGS. 1A and 1B ). The size of each white outlined arrow in  FIG. 3  represents the magnitude of a tensile force F in the front-rear direction. Thus, due to the curved tip end portion  3   a , the tensile force F increases gradually from the widthwise center portion  31  to the widthwise end portions  32 ,  32 . 
         [0035]    The shade  3  is formed of a stretchable fabric body, and is therefore stretchable flexibly in the width direction. This makes it less likely for the shade  3  to have wrinkles or the like in the width direction and thus allow the shade  3  to have an aesthetic finish when supported in the handle member  6 . 
         [0036]    The “tensile force application part” in Claims applies a larger tensile force to the widthwise end portions  32 ,  32  of the shade  3  than to the widthwise center portion  31  of the shade  3 , and in the present embodiment, is formed by the curved tip end portion  3   a  of the shade  3  and the linear support portion  6   d  of the handle member  6 . 
         [0037]    According to the roller sunshade device  1  of the present embodiment described above, the curved tip end portion  3   a  assembled to the support portion  6   d  of the handle member  6  causes a larger tensile force F to be applied to the widthwise end portions  32 ,  32  of the shade  3  than to the widthwise center portion  31  of the shade  3 , making the end portions  32 ,  32  pulled in the front-rear direction more strongly than the center portion  31 . This can advantageously prevent the shade  3  from slackening at the widthwise end portions  32 ,  32  thereof. 
         [0038]    The tensile force application part can be configured in a simple manner because it is only necessary to form the tip end portion  3   a  of the shade  3  into a curved shape. In other words, the prevention of slackening of the shade  3  can be achieved without complicating the structure, increasing the number of components, or lowering operability as a result of increased resistance against unrolling and rolling-up operations. 
         [0039]    The tip end portion  3   a  of the shade  3  has the core material  33  inserted into the accommodation portion  3   c  formed inside the tip end portion  3   a , and therefore can advantageously maintain its state of being assembled to the handle member  6  even though the widthwise end portions  32 ,  32  of the shade  3  are pulled in the unroll direction more strongly than the widthwise center portion  31  of the shade  3 . 
         [0040]    The handle member  6  may be formed straight without curving upward, but when formed to curve upward like in the present embodiment, a larger vehicle compartment space (head clearance) can be provided. However, the handle member  6  formed to curve upward poses a problem in that, as shown in  FIG. 6 , the widthwise end portions  32 A of the shade  3  are more likely to slacken because the distance between reference numerals  30   a  and  30   b  for each widthwise end portion  32 A of the shade  30  is shorter than the distance between reference numerals  30   c  and  30   d  for the widthwise center portion of the shade  30 . Forming the retractor  5  to curve upward in conformity with the shape of the handle member  6  can prevent the shade  30  from slackening at the widthwise end portions  32 A, but complicates the structure. 
         [0041]    In this respect, the roller sunshade device  1  including the tensile force application part of the present embodiment can increase the vehicle compartment space and also make the entire shade  3  taut with a simple structure. 
         [0042]      FIGS. 4A, 4B, 5A, and 5B  show modifications of the roller sunshade device  1 . In the roller sunshade device  1  shown in  FIGS. 4A and 4B , the support portion  6   d  of the handle member  6  forms a curve having a predetermined radius of curvature R2 in such a manner that a widthwise (left-right direction) center portion  61  recesses in the unroll direction (frontward) relative to widthwise end portions  62 ,  62 . 
         [0043]    The relation between a radius of curvature R1 of the tip end portion  3   a  of the shade  3  and the radius of curvature R2 of the handle member  6  (the support portion  6   d ) is set such that “the radius of curvature R1&lt;the radius of curvature R2”. Due to this configuration, when the tip end portion  3   a  of the shade  3  is assembled to the support portion  6   d , the widthwise end portions  32 ,  32  of the shade  3  are pulled in the front-rear direction more strongly than the widthwise center portion  31  of the shade  3 . This can advantageously prevent the shade  3  from slackening at the widthwise end portions  32 ,  32  thereof. Since the radius of curvature R1&lt;the radius of curvature R2, the tensile force F acting on the shade  3  gradually increases from the widthwise center portion  31  to the widthwise end portions  32 ,  32  in the above configuration as well, as shown in  FIG. 4B . 
         [0044]    In the roller sunshade device  1  shown in  FIG. 5A , a tip end portion  3   a   1  of the shade  3  is formed straight in the width direction, while a support portion  6   d   3  of the handle member  6  forms a curve having a predetermined radius of curvature R3 in such a manner that the widthwise (left-right direction) center portion  61  protrudes in the roll-up direction (rearward) relative to the widthwise end portions  62 ,  62 . 
         [0045]    Due to this configuration, when the tip end portion  3   a   1  of the shade  3  is assembled to the support portion  6   d   3 , the widthwise end portions  32 ,  32  of the shade  3  are pulled in the front-rear direction more strongly than the widthwise center portion  31  of the shade  3 . This can advantageously prevent the shade  3  from slackening at the widthwise end portions  32 ,  32  thereof. 
         [0046]    The roller sunshade device  1  shown in  FIG. 5B  is a further modification of the roller sunshade device  1  shown in  FIG. 5A . In this roller sunshade device  1 , a tip end portion  3   a   2  of the shade  3  forms a curve having a predetermined radius of curvature R4 in such a manner that the widthwise (left-right direction) center portion  31  protrudes in the roll-up direction (rearward) relative to the widthwise end portions  32 ,  32 , and a support portion  6   d   4  of the handle member  6  forms a curve having a predetermined radius of curvature R5 in such a manner that the widthwise (left-right direction) center portion  61  protrudes in the roll-up direction (rearward) relative to the widthwise end portions  62 ,  62 . 
         [0047]    The relation between the radius of curvature R4 of the tip end portion  3   a   2  of the shade  3  and a radius of curvature R5 of the handle member  6  (the support portion  6   d ) is set such that “the radius of curvature R4&gt;the radius of curvature R5”. Due to this configuration, when the tip end portion  3   a   2  of the shade  3  is assembled to the support portion  6   d   4 , the widthwise end portions  32 ,  32  of the shade  3  are pulled in the front-rear direction more strongly than the widthwise center portion  31  of the shade  3 . This can advantageously prevent the shade  3  from slackening at the widthwise end portions  32 ,  32  thereof. Since the radius of curvature R4&gt;the radius of curvature R5, the tensile force F acting on the shade  3  gradually increases from the widthwise center portion  31  to the widthwise end portions  32 ,  32  in the above configuration as well, although not shown. 
         [0048]    In the modification of  FIGS. 4A and 4B , the “tensile force application part” in Claims is formed by the curved tip end portion  3   a  of the shade  3  and the curved support portion  6   d  of the handle member  6 . In the modification of  FIG. 5A , the “tensile force application part” in Claims is formed by the straight tip end portion  3   a   1  of the shade  3  and the curved support portion  6   d   3  of the handle member  6 . In the modification of  FIG. 5B , the “tensile force application part” in Claims is formed by the curved tip end portion  3   a   2  of the shade  3  and the curved support portion  6   d   4  of the handle member  6 . 
         [0049]    Although the embodiment of the present invention has been described above, the present invention is not limited to the foregoing embodiment and is modifiable in various ways as follows, for example. 
         [0050]    For example, the present invention is not limited to the forgoing configurations in which the tip end portion  3   a  of the shade  3 , the support portion  6   d  of the handle member  6 , etc. have the predetermined radiuses of curvature. Instead, the tip end portion  3   a  of the shade  3 , the support portion  6   d  of the handle member  6 , etc., may partly have a straight area in the width direction as long as the tensile force F applied to the widthwise end portions  32 ,  32  is larger than that applied to the widthwise center portion  31 . In addition, the present invention is not limited to the foregoing configurations in which, for example, the tip end portion  3   a  of the shade  3  is put inside the support portion  6   d  of the handle member  6  entirely in the width direction. Instead, the tip end portion  3   a  of the shade  3  may be put inside the support portion  6   d  of the handle member  6  partly in the width direction as long as the tensile force F applied to the widthwise end portions  32 ,  32  is larger than that applied to the widthwise center portion  31 . 
         [0051]    Moreover, the shade  3  may be formed from a fabric body which is stretchable in the front-rear direction only at its widthwise end portions. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  roller sunshade device 
           3  shade 
           3   a ,  3   a   1 ,  3   a   2  tip end portion (tensile force application part) 
           6  handle member 
           6   d ,  6   d   3 ,  6   d   4  support portion (tensile force application part) 
           31  center portion 
           32  end portion 
           33  core material 
           61  center portion 
           62  end portion 
         F tensile force