Patent Publication Number: US-2018036978-A1

Title: Bead core manufacturing apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a bead core manufacturing apparatus for forming a bead core. 
     BACKGROUND ART 
     Japanese Patent Application Publication NO. 2013-78902 (Patent Document 1) discloses a bead core manufacturing method in which a bead core is manufactured by winding a bead wire on a bobbin with flanges disassemblable into sectors. 
     SUMMARY OF THE INVENTION 
     The bead core has to have an inside diameter being appropriate to the tire size or the recommended wheel rim size. Therefore, in the method disclosed in Patent Document 1, it is necessary to change the bobbin to another bobbin in order to manufacture plural kinds of bead cores having different inside diameters. Such replacement work possibly decrease the production efficiency, and it is necessary to prepare and manage the plural kinds of bobbins. 
     In view of the circumstances as described above, the present invention was made, and a primary object of the present invention is to provide a bead core manufacturing apparatus capable of manufacturing bead cores having different inside diameters without using plural kinds of bobbins. 
     According to the present invention, a bead core manufacturing apparatus comprises: 
     an annular former having an outer peripheral surface around which a bead wire is woundable to form a bead core, wherein 
     the former comprises a plurality of segments, which are divided circumferentially of the former, and which have radially outer surfaces collectively forming the above-said outer peripheral surface, and 
     the segments are movable in respective radial directions of the former so that the above-said outer peripheral surface has plural outside diameters, and a bead wire can be wound into plural kinds of bead cores having different inside diameters. 
     Therefore, in the bead core manufacturing apparatus according to the present invention, by moving the segments to different radial positions and winding a bead wire thereon, plural kinds of bead cores having different inside diameters can be manufactured without the need for the bobbin replacement work. Thus, the production efficiency can be improved. 
     Further, the bead core manufacturing apparatus according to the present invention may have the following features:
     (1) the above-said radially outer surfaces of the segments have a curvature, and the segments are movable between a first radial position at which the outside diameter of the above-said outer peripheral surface becomes smaller than the diameter of the above-said curvature, and   

     a second radial position at which the outside diameter of the above-said outer peripheral surface becomes larger than the diameter of the above-said curvature;
     (2) the former is provided with a circumferentially extending groove in which the bead wire is woundable;   (3) the former is provided with a plurality of circumferentially extending grooves in each of which the bead wire is woundable;   (4) the former is provided with a circumferentially extending first groove in which the bead wire is woundable to form the bead core having a first inside diameter, and a circumferentially extending second groove in which the bead wire is woundable to form the bead core having a second inside diameter larger than the first inside diameter;   (5) one or more of the segments comprises a main part and a width changing part,   

     the main part is provided with a part of the or each circumferentially extending groove of which groove bottom forms a part of the above-said outer peripheral surface, and 
     the width changing part is movable relative to the main part to change the width of the above-said part of the circumferentially extending groove;
     (6) the bead core manufacturing apparatus further comprises an expanding/contracting means for moving the segments in the respective radial directions;   (7) the expanding/contracting means comprises radial support portions, to which the segments are respectively fixed, and which are supported movably in the respective radial directions, and   

     a driving unit for the radial support portions, and the driving unit is movable in the axial direction of the former to move the radial support portions in the respective radial directions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side view of as an embodiment of the present invention showing a contracted state of the former. 
         FIG. 2  is a schematic side view of the former thereof showing an expanded state in which the segments are moved radially outward. 
         FIG. 3  is a cross sectional view of the former in the contracted state taken along line A-A of  FIG. 1 . 
         FIG. 4  is a cross sectional view of the former in the expanded state taken along line B-B of  FIG. 2 . 
         FIG. 5  is a perspective view of a first segment shown in  FIG. 4 . 
         FIG. 6  is a perspective view of a second segment shown in  FIG. 4 . 
         FIG. 7  is a perspective view of a third segment shown in  FIG. 4 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will now be described in conjunction with accompanying drawings. 
     In the drawings, bead core manufacturing apparatus  1  according to the present invention comprises a wire supplying section  2  for supplying a bead wire w, and a winding section  3  in which the supplied bead wire w is wound into an annular bead core. The winding section  3  comprises an annular former  4  around which the bead wire w is wound into the bead core, and a rotating device (not shown) for rotating the former  4 . 
     The former  4  comprises at least one set of segments  41  which are divided in the circumferential direction of the former  4 , and has radially outer surfaces collectively forming an outer peripheral surface  40  on which the bead wire w is woundable. As shown in  FIGS. 1 and 2 , in the side view, the radially outer surfaces of the respective segments  41  in each segment set have a radius RF of curvature. 
     The segments  41  in each segment set are movable in the respective radial directions, therefore, the above-mentioned outer peripheral surface  40  can have plural outside diameters. Accordingly, the bead wire w wound on the outer peripheral surface  40 , namely, the bead core can have plural inside diameters. 
       FIG. 1  shows a contracted state of the former  4  in which the segments  41  in each segment set are moved radially inwardly to respective first radial positions L 1  at which the outside diameter (or outside radius RC 1 ) of the outer peripheral surface  40  is smaller than the above-mentioned radius RF of curvature of the concerned segments  41 . 
     Thus, the bead core having an inside diameter corresponding to the outside radius RC 1  which is small than the radius RF of curvature, can be manufactured. 
     In order to remove the wound bead wire, namely, bead core from the segments  41 , the segments  41  are movable radially inwardly beyond the above-said first radial positions L 1 . 
       FIG. 2  shows an expanded state of the former  4  in which the segments  41  in each segment set are moved radially outwardly to respective second radial positions L 2  at which the outside diameter (or outside radius RC 2 ) of the outer peripheral surface  40  is larger than the above-mentioned radius RF of curvature of the concerned segments  41 . 
     Thus, the bead core having an inside diameter corresponding to the outside radius RC 2  which is larger than the radius RF of curvature can be manufactured. 
     The segments  41  can be stopped in a nonstepped manner or stepped manner at least in a movable range between the first radial position L 1  and the second radial position L 2 . Thus, it is possible to manufacture the bead cores with a variety of inside diameters. 
     At each of the first radial position L 1  and second radial position L 2 , the outer peripheral surface  40  formed by the segments  41  is slightly deviated from a perfect circle or perfect circular cylinder. However, when the wound bead core is removed from such outer peripheral surface  40 , the shape of the bead core become an almost perfect circle because of the elastic deformation. Thus, there is no possibility of negative effect on the tire uniformity. 
     The above-mentioned movable range of the segments  41  includes a radial position at which the outside diameter or radius of the outer peripheral surface  40  becomes equal to the radius RF of curvature of the segments  41 , therefore, it is possible to manufacture the bead core having an excellent roundness, while decreasing the number of segments  41  to simplify the structure of the former  4 . 
     The winding section  3  further comprises an expanding/contracting means  5  for moving the segments  41  in the respective radial directions. 
     The expanding/contracting means  5  comprises a plurality of radial support portions  51 , which are supported movably in the respective radial directions, and to which the segments  41  are respectively fixed, and 
     a driving unit  52  for the radial support portions  51 . 
     In this embodiment, as shown in  FIGS. 3 and 4 , each of the radial support portions  51  comprises a bent plate having a substantially L- or v-shape in a cross section parallel with a plane including the central axis of the former. The bent plate is composed of a radial part supported movably in the radial direction by a slider  53 , and a slant part extending radially inwardly from the radially outer edge of the radial part. The segments  41  are fixed to the radially outer surfaces of the slant parts. 
     In this embodiment, as shown in  FIGS. 3 and 4 , the drive unit  52  comprises a cone part  54  having an outer surface having a circular truncated cone shape. 
     The cone part  54  is disposed concentrically with the central axis of the former  4 , and is movable in the axial direction of the former  4 . 
     The outer surface of the cone part  54  contacts, indirectly via sliders  55 , with the slanting radially inner surfaces of the slant parts of the radial support portions  51 . 
     Accordingly, by moving the cone part  54  in the axial direction, the radial support portions  51  can be moved in the respective radial directions. And the segments  41  can be stopped at desired radial positions to arbitrarily change the outside diameter of the outer peripheral surface  40 . 
     The former  4  is provided with at least one groove  42 , which extends in the circumferential direction of the former, and in which the bead wire w is wound. 
     Thereby, the bead wire w is guided during winding, and it is possible to accurately and stably manufacture the bead core. In this embodiment, the bottom of the groove  42  which forms the outer peripheral surface  40  is flat, but the bottom may be profiled according to the shape of the bead core to be manufactured. For example, the bottom may be tapered. Preferably, two or more grooves  42  are disposed side by side in the axial direction of the former  4  in order that a plurality of bead cores can be manufactured at the same time. In this case, it is possible to configure the grooves  42  to have different radii so that bead cores having different inside diameters can be manufactured at the same time. 
     In this embodiment, as shown in  FIG. 1 , the former  4  comprises two sets of the segments  41 , one set of the segments  41   L  and one set of the segments  415 . The segments  41   L  have radially outer surfaces forming the outer peripheral surface  40  having a larger outer diameter. The segments  41   S  have radially outer surfaces forming the outer peripheral surface  40  having a smaller outer diameter. Thus, the former  4  in this embodiment can be said as a combination of a former  4   L  for manufacturing a bead core having a large inside diameter, and a former  4 S for manufacturing a bead core having a small inside diameter. 
     Each set of the segments  41  is provided with two grooves  42  as shown in  FIG. 3  and  FIG. 4 . 
       FIG. 3  shows the winding section  3  wherein the segments  41  are positioned at their first radial positions L 1 . 
       FIG. 4  shows the winding section  3  wherein the segments  41  are positioned at their second radial positions L 2 . 
     As shown, the segments  41 S are provided with two identical first grooves  42  disposed side by side in the axial direction so as to be able to simultaneously manufacture two bead cores having the same first inside diameter. 
     The segments  41 L are provided with two identical second grooves  42  disposed side by side in the axial direction so as to be able to simultaneously manufacture two bead cores having the same second inside diameter greater than the first inside diameter. Thus, it is possible to simultaneously manufacture four bead cores having two different inside diameters. 
     In this embodiment, as shown in  FIG. 2 , each segment set (set of  41 L and set of  41 S) includes three kinds of the segments  41 , namely, a first segment  41 A, a second segment  41 B and a third segment  41 C. 
     The first segment  41 A is provided with a function for chucking the bead wire w, and used to chuck the winding start end of the bead wire w. Each segment set (set of  41 L and set of  41 S) includes at least one first segment  41 A. 
     The first segment  41 A in this embodiment is shown in  FIG. 5 . As shown, the first segment  41 A comprises a main part  61  provided with a circumferential part of the above-said circumferentially extending groove  42 , 
     a chuck piece  62  disposed in the circumferential part of the groove  42  and being movable in the axial direction of the former  4 , and 
     a driving unit  63  for moving the chuck piece  62  in the axial direction of the former  4 . 
     By moving the chuck piece  62  toward a side wall of the above-said circumferential part of the groove  42 , the bead wire w is secured between the chuck piece  62  and the groove side wall. Thus, when winding the bead wire W within the groove  42 , it is possible to hold the winding start end of the bead wire w at the predetermined circumferential position. 
     In the first segment  41 A shown in  FIG. 5 , the main part  61  is provided circumferential parts of the two grooves  42 , and accordingly, two sets of the chuck piece  62  and the driving unit  63  are provided. 
     The second segment  41 B is shown in  FIG. 6 . As shown, the second segment  41 B comprises 
     a main part  61  provided with a circumferential part of each groove  42 , and 
     a width changing part  72  for changing the width of the circumferential part. 
     The width changing part  72  constitutes one of the side walls of the above-said circumferential part of each groove  42 . By moving the width changing part  72  in the axial direction of the former  4  toward the other of the side walls, the width of the groove  42  is changed. Thus, the second segment  41 B serves to manufacture the bead cores having different widths. 
     The third segment  41 C is shown in  FIG. 7 . As shown, the above described width changing part  72 , chuck piece  62  and driving unit  63  are omitted. The third segment  41 C comprises a main part  81  provided with a circumferential part of each groove  42 . 
     The groove width of each groove  42  is variable in the second segment  41 B, but constant in the first segment  41 A and the third segment  41 C. The groove width in the first segment  41 A and the groove width in the third segment  41 C are larger than the maximum groove width in the second segment  41 B. 
     In each segment set, a plurality of second segments  41 B with a variable groove width can be arranged in series in the circumferential direction. But, in this embodiment in which only one first segment  41 A is included in each segment set, the second segments  41 B with a variable groove width are arranged alternately with the first and third segments  41 A and  41 C with a constant groove width in order to simply the structure of the former  4  while achieving the bead core having the desired accurate shape formed by the bead wire w wound in order. 
     Next, a bead core manufacturing method using the bead core manufacturing apparatus  1  is described briefly. 
     Firstly, according to the bead core to be manufactured, the inside diameter, width, height, number of turns, etc. are determined. According thereto, the width changing parts  72  of the second segments  41 B are adjusted to an adapted groove width, and all the segments  41  are moved to a certain radial position by moving the cone part  54 . 
     Then, the bead wire w is drawn from the wire supplying section  2 , and the end of the bead wire w is chucked by the chuck piece  62  and secured to the first segment  41 A. 
     subsequently, the former  4  is rotated by the rotating device (not shown) such as a geared motor so that the bead wire w is wound within the groove  42 , while the bead wire w is guided, for example by a guide pulley if needed. 
     when the bead wire w has been wound to the predetermined number of turns, the bead wire w is cut, and the cut end is fixed to the wound bead wire w. The segments  41  are moved radially inwardly, and the wound bead wire w is took out from the formed  4 . Thus, the bead core is manufactured. 
     while detailed description has been made of a preferable embodiment of the present invention, the present invention can be embodied in various forms without being limited to the illustrated embodiment. 
     DESCRIPTION OF THE REFERENCE SIGNS 
       1  bead core manufacturing apparatus 
       4  former 
       40  outer peripheral surface 
       41  segment 
       42  groove 
       51  radial support portion 
       52  driving unit for radial support portions 
       71  main part 
       72  width changing part 
     w bead wire