Abstract:
A molding apparatus includes an extrusion die having an extruding orifice and a projection forming orifice, and a rotor rotatably installed in a middle portion of the extrusion die and having a forming recess adjacent to the projection forming orifice.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of priority to Korean Patent Application No. 10-2015-0080580, filed on Jun. 8, 2015 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to a molding apparatus and, more particularly, to a molding apparatus capable of simply and precisely forming an extrusion product having a shape in which one or more projections are integrally formed in a body part by adopting a structure enabling extrusion forming and projection forming to be simultaneously performed. 
       BACKGROUND 
       [0003]    Extrusion is a mold process used to create objects of a fixed cross-sectional profile in a length direction. Through extrusion, an extrusion product having a desired cross-sectional profile may be obtained by an extruder having an extruding aperture with a desired shape. Such products of extrusion are widely used in various fields such as automobiles and manufacturing. 
         [0004]      FIG. 1  illustrates a configuration of a weather strip for a vehicle. The weather strip for a vehicle illustrated in  FIG. 1  has a structure in which one or more projections  2  are integrally provided on one side of a body part  1 , and the body part  1  has an extruded shape with a fixed cross-sectional profile in a length direction. 
         [0005]    In order to mold the product illustrated in  FIG. 1 , in the related art, after the body part  1  is extruded through an extrusion process, one or more projections  2  are molded with respect to the extruded body part  1  through insert-injection molding, thus integrating the one or more projections  2  with the body part  1 . 
         [0006]    Thus, in the related art manufacturing method, two stages of the extrusion process and the insert-injection process are performed, making the manufacturing process cumbersome and lengthening a manufacturing time and increasing manufacturing costs. 
       SUMMARY 
       [0007]    The present disclosure has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact. 
         [0008]    An aspect of the present disclosure provides an extrusion molding apparatus configured to rotate one or more rotors having a forming recess for forming a projection in a middle portion of an extrusion die to thereby perform extrusion forming and projection forming through a single process, whereby a product having an extrusion shape with one or more projections integrally formed thereon is quickly and precisely formed. 
         [0009]    According to an exemplary embodiment of the present disclosure, a molding apparatus may include: an extrusion die having an extruding orifice and a projection forming orifice; and a rotor rotatably installed in a middle portion of the extrusion die and having a forming recess adjacent to the projection forming orifice. 
         [0010]    The extruding orifice may form an extrusion shape, and the projection forming orifice may form a projection shape in cooperation with the forming recess. 
         [0011]    The extruding orifice may include a first extruding orifice disposed at an upstream side of the forming recess and a second extruding orifice disposed at a downstream side of the forming recess, and the projection forming orifice may include a first projection forming orifice disposed at the upstream side of the forming recess and a second projection forming recess disposed at the downstream side of the forming recess. 
         [0012]    The first extruding orifice and the second extruding orifice may have the same shape and the same size. 
         [0013]    The first projection forming orifice may have a cross-sectional area larger than that of the second projection forming orifice. 
         [0014]    The extrusion die may include a first extrusion die positioned in a direction in which a material is introduced and a second extrusion die positioned in a direction in which the material is discharged. 
         [0015]    The first extruding orifice and the first projection forming orifice may be formed in the first extrusion die, and the second extruding orifice and the second projection forming orifice may be formed in the second extrusion die. 
         [0016]    The rotor may be rotatably installed between the first extrusion die and the second extrusion die. 
         [0017]    An accommodation surface rotatably accommodating the rotor may be provided in portions of the first extrusion die and the second extrusion die facing each other. 
         [0018]    The accommodation surface may be provided to correspond to an outer surface of the rotor. 
         [0019]    According to another exemplary embodiment of the present disclosure, a molding apparatus for forming an extrusion product having an extrusion shape and including one or more projections integrally formed thereon, may include: an extrusion die having an extruding orifice for forming the extrusion shape and a projection forming orifice for forming a projection shape; and a rotor rotatably installed in a middle portion of the extrusion die and having a forming recess for forming the projection shape in cooperation with the projection forming orifice. 
         [0020]    The extrusion die may include a first extrusion die positioned in a direction in which a material is introduced and a second extrusion die positioned in a direction in which the material is discharged. 
         [0021]    The first extrusion die may have a first extruding orifice and a first projection forming orifice, the second extrusion die may have a second extruding orifice and a second projection forming orifice, the first extruding orifice and the second extruding orifice may communicate with each other, and the first projection forming orifice and the second projection forming orifice may communicate with each other. 
         [0022]    The rotor may be rotatably installed between the first extrusion die and the second extrusion die. 
         [0023]    An accommodation surface rotatably accommodating the rotor may be provided in portions of the first extrusion die and the second extrusion die facing each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The above and other objects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings. 
           [0025]      FIG. 1  is a perspective view illustrating a configuration of a weather strip for a vehicle. 
           [0026]      FIG. 2  is a perspective view illustrating a molding apparatus according to an exemplary embodiment of the present disclosure. 
           [0027]      FIG. 3  is a view taken along a direction indicated by the arrow “A” of  FIG. 2 . 
           [0028]      FIG. 4  is a cross-sectional view taken along line B-B of  FIG. 3 . 
           [0029]      FIG. 5  is an exploded perspective view illustrating a state in which first and second extrusion dies and a rotor are separated in a molding apparatus according to an exemplary embodiment of the present disclosure. 
           [0030]      FIG. 6  is an enlarged view of a forming recess of the rotor of  FIG. 5 . 
           [0031]      FIG. 7  is a view illustrating a state in which a pair of rotors is assembled to a first extrusion die and a second extrusion die is separated from the first extrusion die. 
           [0032]      FIG. 8  is a view illustrating a process of forming a product through a molding apparatus according to an exemplary embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Hereinafter, exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. For reference, dimensions of elements or thicknesses of lines illustrated in the drawings referred to describe the present disclosure may be exaggerated to aid understanding. Also, the terms used henceforth have been defined in consideration of the functions of the present disclosure, and may be altered according to the intent of a user or operator, or conventional practice. Therefore, the terms should be defined on the basis of the entire content of this specification. 
         [0034]    As illustrated in  FIGS. 2 through 7 , a molding apparatus according to an exemplary embodiment of the present disclosure may include extrusion dies  11  and  12  respectively having extruding orifices  13  and  14  and a pair of rotors  21  and  22  rotatably installed in the middle of the extrusion dies  11  and  12 . 
         [0035]    As illustrated in  FIGS. 2 through 7 , the extrusion dies  11  and  12  may include a first extrusion die  11  positioned in a direction in which a material is introduced and a second extrusion die  12  positioned in a direction in which a material is discharged. 
         [0036]    The first extrusion die  11  may have a first extruding orifice  13  and a first projection forming orifice  15 . 
         [0037]    The second extrusion die  12  may have a second extruding orifice  14  and a second projection forming orifice  16 . 
         [0038]    As illustrated in  FIG. 3 , the first extruding orifice  13  of the first extrusion die  11  and the second extruding orifice  14  of the second extrusion die  12  may have the same shape and same size. Thus, as illustrated in  FIG. 4 , when the first extrusion die  11  and the second extrusion die  12  are assembled, the first extruding orifice  13  and the second extruding orifice  14  may communicate with each other, and accordingly, a material, while passing through the first extruding orifice  13  and the second extruding orifice  14 , may be extruded to form a body part  1  having a fixed cross-sectional profile in a length direction as illustrated in  FIG. 8 . For example, the first extruding orifice  13  of the first extrusion die  11  and the second extruding orifice  14  of the second extrusion die  12  may be extruding paths for forming an extruding shape having the same extruding cross-sectional profile as that of the body part  1  of  FIG. 1 . 
         [0039]    Also, as the first extrusion die  11  and the second extrusion die  12  may be assembled as illustrated in  FIG. 4 , the first projection forming orifice  15  of the first extrusion die  11  and the second projection forming orifice  16  of the second extrusion die  12  may communicate with each other. The first projection forming orifice  15  and the second projection forming orifice  16  may cooperate with forming recesses  23  and  24  of the rotors  21  and  22  as described hereinafter to integrally form one or more projections  2  on a lower portion of the body part  1  as illustrated in  FIG. 8 . That is, the first projection forming orifice  15  and the second projection forming orifice  16  may be projection forming paths for forming a projection shape such as the projection  2  of  FIG. 1 . 
         [0040]    The pair of rotors  21  and  22  may be rotatably installed in mutually opposite directions between the first extrusion die  11  and the second extrusion die  12 , and the forming recesses  23  and  24  for forming the projections  2  of  FIG. 1  may be provided in the rotors  21  and  22 , respectively. 
         [0041]    The first extrusion die  11  and the second extrusion die  12  each may have accommodation surfaces  17  and  18  rotatably accommodating the rotors  21  and  22  in portions thereof facing each other. 
         [0042]    As illustrated in  FIG. 4 , a pair of accommodation surfaces  17  and  18  corresponding to the pair of rotors  21  and  22  may be formed to be symmetrical bilaterally on one side of the first extrusion die  11 , and the accommodation surfaces  17  and  18  may be provided to be curved to correspond to outer circumferential surfaces of the rotors  21  and  22 , respectively. 
         [0043]    Although not shown in  FIG. 5 , a pair of accommodation surfaces  17  and  18  may also be provided to be curved to correspond to the outer circumferential surfaces of the rotors  21  and  22  on one side of the second extrusion die  12 . 
         [0044]    As illustrated in  FIGS. 3, 5 and 7 , the forming recesses  23  and  24  may be provided on upper edges of the rotors  21  and  22 , respectively. As the pair of rotors  21  and  22  rotate in a facing manner such the pair of forming recesses  23  and  24  face each other, the shape corresponding to the projections  2  of  FIG. 1  may be formed. As illustrated in  FIG. 3 , the pair of forming recesses  23  and  24  may have a mutually symmetrical shape to precisely form the shape corresponding to the projections  2 . 
         [0045]    The pair of forming recesses  23  and  24  may be disposed between the first projection forming orifice  15  of the first extrusion die  11  and the second projection forming orifice  16  of the second extrusion die  12 . Thus, when a material is transferred through the first projection forming orifice  15 , the pair of rotors  21  and  22  may rotate to face each other and the pair of forming recesses  23  and  24  may first form the material to have a shape corresponding to the projection  2  of  FIG. 1 , and the first formed portion may be discharged through the second projection forming orifice  16 , thus forming a product having the projection  2  provided on a lower portion of the body part  1  as illustrated in  FIG. 8 . 
         [0046]    That is, the pair of forming recesses  23  and  24  may be parts for forming the projection  2 , and the first projection forming orifice  15  may be a transfer path for transferring an introduced material to the forming recesses  23  and  24  and the second projection forming orifice  16  may be a finishing path finishing a shape of the projection  2  formed by the forming recesses  23  and  24  of the rotors  21  and  22  as described hereinafter. 
         [0047]    In particular, as illustrated in  FIG. 3 , the first projection forming orifice  15  may have a cross-sectional area larger than that of the second projection forming orifice  16 , and thus, the material may be more smoothly introduced to the first projection forming orifice  15  of the first extrusion die  11 , whereby the projection  2  may be more precisely formed. 
         [0048]    The second projection forming orifice  16  may have the same shape and the same size as those of the projection  2  of a product, and in particular, the second projection forming orifice  16  may have substantially the same shape and size as those of the pair of forming recesses  23  and  24  as illustrated in  FIG. 3 , so that a portion formed by the forming recesses  23  and  24  may be more precisely finished. 
         [0049]    In the molding apparatus according to the present disclosure configured as described above, an extrusion forming process and a projection forming process performed in the process of introducing a material to the first extrusion die  11  and subsequently discharging the material through the second extrusion die  12  will be described in detail. 
         [0050]    When a material is introduced to the first extruding orifice  13  and the first projection forming orifice  15  of the first extrusion die  11 , the material may be extruded, while passing through the first extruding orifice  13  and the second extruding orifice  14 , to form the body part  1  having a fixed cross-sectional profile in the length direction as illustrated in  FIG. 8 . 
         [0051]    Also, the material transferred through the first projection forming orifice  15  may be formed as the projection  2  integrally formed in the body part  1  as illustrated in  FIG. 8 , by the forming recesses  23  and  24  of the rotors  21  and  22  and the second projection forming orifice  16 . 
         [0052]    A projection forming process for forming the projection  2  will be described in detail. When the pair of rotors  21  and  22  rotate in opposite directions such that the pair of forming recesses  23  and  24  face each other as illustrated in  FIG. 7 , a material may be transferred through the first projection forming orifice  15  and a portion thereof corresponding to the projection  2  of  FIG. 1  may be first formed by the pair of forming recesses  23  and  24  facing each other. The first formed portion then may pass through the second projection forming orifice  16  of the second extrusion die  12  so as to be precisely finished in shape, and thereafter, a product in which the projection  2  may be integrally formed on the lower end of the body part  1  as illustrated in  FIG. 8  may be discharged. 
         [0053]    In a case where a plurality of projections  2  are intended to be formed in a lower end of the body part  1  at a predetermined interval, a rotating speed of the rotors  21  and  22  may be adjusted to appropriately adjust a space between the projections  2 . 
         [0054]    In the above descriptions, it is described that shapes and sizes of the first extruding orifice  13 , the second extruding orifice  14 , the first projection forming orifice  15 , and the second projection forming orifice  16  may correspond to those of the product illustrated in  FIG. 1 , but a molding apparatus according to an exemplary embodiment of the present disclosure is not limited to a formation of the product shape of  FIG. 1 , and may form various other product shapes. Thus, the shapes and sizes of the first extruding orifice  13 , the second extruding orifice  14 , the first projection forming orifice  15 , and the second projection forming orifice  16  may be variously modified according to shapes and sizes of a product intended to be formed. 
         [0055]    As described above, according to an exemplary embodiment of the present disclosure, since one or more rotors having forming recesses for forming a projection may be configured to rotate in a middle portion of the extrusion die, extrusion forming and projection forming may be performed through a single process, whereby a product having an extrusion shape in which one or more projections may be integrally formed may be rapidly and precisely formed. 
         [0056]    Hereinabove, although the present disclosure has been described with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.