Abstract:
A vehicle seat includes: a trim cover including: a plurality of surface materials joined each other; a core material; a welt surface material wrapping the core material; a welt provided along a seam of two pieces of joined surface materials; and an empty core part provided with the welt, the empty core part reaching one end of the welt; and a seat element overlapped on the empty core part.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-088336, filed on Apr. 26, 2016, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
     1. Field of the Invention 
       [0002]    The present invention relates to a vehicle seat. 
       2. Description of the Related Art 
       [0003]    A vehicle seat typically includes a cushioning pad and a trim cover that covers the cushioning pad, and the trim cover is made by joining a plurality of surface materials. From a view of improving the design of the seat, a welt may be provided along the seam of two pieces of surface materials which are joined (for example, refers to JP-UM-Y-H03-24160). The welt includes a core material and a welt surface material which wraps the core material, and the core material is typically provided along the full length of the welt. 
         [0004]    To hide mechanical parts such as a reclining mechanism or a seat sliding mechanism that expose at the side of a seat cushion, the side of the seat cushion is covered by a side finish made of synthetic resin. The side finish may be overlapped on a welt provided along a seam of a surface material which forms a bearing surface of the seat cushion and a surface material which forms a side surface of the seat cushion. In this case, the welt separates from the side finish as a passenger sits down, and the welt contacts the side finish as the passenger leaves. When the separation and the contact are repeated, a tear may occur at the welt surface material that wraps the core material of the welt, and the appearance quality of the seat may be spoiled. 
       SUMMARY 
       [0005]    The present invention is made in view of the above circumstances, and the object of the present invention is to prevent a tear of a welt surface material which wraps a core material of the welt, and to improve the appearance quality of a vehicle seat. 
         [0006]    According to an aspect of the present invention, there is provided a vehicle seat including: a trim cover including: a plurality of surface materials joined each other; a core material; a welt surface material wrapping the core material; a welt provided along a seam of two pieces of joined surface materials; and an empty core part provided with the welt, the empty core part reaching one end of the welt; and a seat element overlapped on the empty core part. 
         [0007]    According to the present invention, a tear of a welt surface material which wraps a core material of the welt can be prevented, and the appearance quality of a vehicle seat can be improved. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawing which is given by way of illustration only, and thus is not limitative of the present invention and wherein: 
           [0009]      FIG. 1  is a perspective view of a vehicle seat example to describe an embodiment of the present invention; 
           [0010]      FIG. 2  is a sectional view of a welt of a trim cover of  FIG. 1 ; 
           [0011]      FIG. 3  is an enlarged perspective view of the trim cover of a seat cushion in an area surrounded by the dashed circle III of  FIG. 1 ; 
           [0012]      FIG. 4  is an enlarged perspective view of the trim cover of a seat pack in the area surrounded by the dashed circle III of  FIG. 1 ; and 
           [0013]      FIG. 5  is a perspective view of the base side of the trim cover of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]      FIG. 1  shows an example of the vehicle seat to describe an embodiment of the present invention. 
         [0015]    A vehicle seat  1  shown in  FIG. 1  includes a seat cushion  2  that forms a bearing portion, and a seat pack  3  that forms a back portion. The seat cushion  2  and the seat pack  3  have a cushioning pad made of foams such as urethane foam, and a frame which supports the cushioning pad, respectively. The cushioning pad of the seat cushion  2  is covered by a trim cover  5 , and the cushioning pad of the seat pack  3  is covered by a trim cover  6 . 
         [0016]    The trim covers  5 ,  6  are made by joining a plurality of surface materials, and, for example, leather (natural leather, synthetic leather) or cloth (textile, knitting, nonwoven fabric) are used as the surface materials. The surface material may have a single-layered structure of leather or cloth, and may have a multilayer structure in which a wadding (for example, resin foam such as elastically deformable flexible polyurethane foam) is laminated on leather or cloth as an outer material. The trim cover  5 ,  6  may be formed of one kind of surface material, and may be formed of a plurality of different surface materials at different positions. 
         [0017]    The trim cover  5  of the seat cushion  2  is provided with a welt  12  along the seam of a surface material  10  that forms the bearing surface of the seat cushion  2  and a surface material  11  that forms the side surfaces of the seat cushion  2 . Further, the trim cover  6  of the seat pack  3  is provided with a welt  15  along the seam of a surface material  13  that forms a back surface of the seat pack  3  and a surface material  14  that forms the side surfaces of the seat pack  3 . 
         [0018]      FIG. 2  shows a schematic configuration of the welt  12  of the trim cover  5 . 
         [0019]    The welt  12  includes a core material  20 , and a welt surface material  21  that wraps the core material  20 . For example, resin cord or paper cord that has flexibility is used as the core material  20 . For example, leather (natural leather, synthetic leather) or cloth (textile, knitting, nonwoven fabric) is used as the welt surface material  21 . 
         [0020]    When the welt surface material  21  is folded in two, and sewed together with sewing regions  10   a ,  11   a  of the surface materials  10 ,  11 , the welt surface material is formed into a pipe which extends along the seam of the surface materials  10 ,  11 . The welt  12  is constructed by inserting the core material  20  through the pipe formed of the welt surface material  21 . 
         [0021]    The welt  15  of the trim cover  6  is also constructed similarly. 
         [0022]      FIG. 3  shows a detailed configuration of the welt  12  of the trim cover  5 . 
         [0023]    A side of the seat cushion  2  is covered by a side finish  7  made of synthetic resin. The side finish  7  is overlapped on a part of the end side of the welt  12 . The welt  12  is provided with an empty core part  22  which reaches one end of the welt  12 , and the side finish  7  is overlapped on the empty core part  22 . The empty core part  22  refers to such a part where the core material  20  is not received inside the pipe formed of the welt surface material  21 , and only the welt surface material  21  is included. 
         [0024]    With the sitting and leaving of a passenger, contact and separation between the empty core part  22  and the side finish  7  are repeated, but because the core material  20  is not received in the empty core part  22 , and the welt surface material  21  is not sandwiched between the core material  20  and the side finish  7  in the case of contact with the side finish  7 , the load that is applied to the welt surface material  21  is reduced. Thereby, a tear of the welt surface material  21  can be prevented. 
         [0025]      FIGS. 4 and 5  show a detailed configuration of the welt  15  of the trim cover  6 . 
         [0026]    The surface material  13  that forms the back surface of the seat pack  3  and the surface material  14  that forms the side surface of the seat pack  3  are joined with a surface material  16  that forms a lower end surface of the seat pack  3 , and sewing regions  13   a ,  14  of the surface materials  13 ,  14  and a sewing region  16   a  of the surface material  16  are overlapped and sewed together. 
         [0027]    A part at the end side of the welt  15  provided along the seam of the surface materials  13 ,  14  is overlapped and sewed together with the sewing regions  13   a ,  14   a  of the surface materials  13 ,  14 , and the sewing region  16   a  of the surface material  16 . The welt  15  is provided with an empty core part  22  which reaches one end of the welt  15 , and the empty core part  22  and the sewing region  16   a  are overlapped and sewed together. 
         [0028]    Because the core material  20  is not received in the empty core part  22 , and when sewed with the sewing region  16   a , the welt surface material  21  is not sandwiched between the core material  20  and sewing thread, the load applied to the welt surface material  21  is reduced. Thereby, a tear of the welt surface material  21  can be prevented. Because a sewing needle does not need to be pierced into the core material  20  which is relatively rigid, sewing becomes easy and the sewing quality of the trim cover  6  can be stabilized.