Patent Publication Number: US-11654474-B2

Title: Wire feeding unit and wire bending apparatus including the same

Description:
BACKGROUND 
     1. Field 
     The following description relates to a wire feeding unit which supplies a wire to a bending apparatus for bending the wire and a wire bending apparatus including the wire feeding unit. 
     2. Description of Related Art 
     Generally, wire bending machines are widely used in a wide range of applications ranging from two-dimensional machining to three-dimensional shape machining owing to the advantage in that they can process quickly and inexpensively various shaped workpieces used in complicated and various types of parts, such as automobile parts, industrial machine parts, materials used in office supplies, medical supplies, construction materials, and the like, from mass production to small quantity production. A wire bending apparatus may be largely divided into a straightener for straightening a wire, a feeding device for transferring the wire, and a head portion for performing at least one of folding, bending, and cutting. The feeding device rotates while pressurizing the wire using a plurality of feeding rollers and transfers the wire of a predetermined length. At this time, there may occur a case in which the wire deviates from the belt or roller in contact with the wire along a feeding direction in the course of feeding the wire and there may be problems in that feeding power may not be transferred to the wire to be fed and the feeding power is lost due to an occurrence of slippage. 
     A difference between a numerical control value and an actually transferred value may be caused by deviation and slippage of a wire transferred by a controller so that bending or folding may be processed at a point in time different from a set value. 
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     The present disclosure is to solve problems of the above-described conventional wire feeding unit and one objective of the present disclosure is to reduce resistance to a feeding direction by limiting a configuration which is in direct contact with a wire to a belt and an idler to reduce a contact area and to prevent twisting that occurs in the course of feeding by increasing the contact area through the belt. 
     Another objective of one embodiment of the present disclosure is to provide a feeding power generated by one driving motor as a feeding force, wherein a wire is fed through the contact between a belt that rotates by the feeding power and a freely rotatable idler. 
     Still another objective of one embodiment of the present disclosure is to prevent a wire from deviating in position by forming a guide groove that allows a wire to be seated therein on an idler that is brought into contact with the wire. 
     In one general aspect, a wire feeding unit includes a driving motor; a driving roller which rotates by a driving force of the driving motor; a plurality of driven rollers arranged such that outer circumferential surfaces thereof are positioned on a same line; a belt which interlocks the driving roller and the plurality of driven rollers and is brought into contact with a wire, which is drawn into a side of the driven rollers, on a side of the plurality of driven rollers; and a plurality of idlers which support the wire on a side in which the wire and the belt are in contact with each other and assist feeding of the wire along a feeding direction of the belt in a free-rotation state. 
     Each of the plurality of idlers may have a guide groove formed on an outer circumferential surface to allow the wire to be seated therein. 
     The guide groove may prevent the wire from deviating in position through surface friction greater than or equal to that of a metal material. 
     A depth of the guide groove may be formed to be less than or equal to a radius of the wire and a surface of the guide groove may be in contact with a half of an outer circumferential surface of the wire. 
     The plurality of idlers may be provided and each idler may be positioned to correspond to each of the plurality of driven rollers. 
     The wire feeding unit may further include a cover portion having an auxiliary guide which is a groove for guiding the wire in an auxiliary manner along an arrangement of the plurality of idlers. 
     In another general aspect, a wire bending apparatus includes a wire inserter; a wire feeding unit which feeds a wire that is fed through the wire inserter; and a head portion which bends or folds the wire fed through the wire feeding unit, wherein the wire feeding unit comprises a driving motor, a driving roller which rotates by a driving force of the driving motor, a plurality of driven rollers arranged such that outer circumferential surfaces thereof are positioned on a same line, a belt which interlocks the driving roller and the plurality of driven rollers and is brought into contact with a wire, which is drawn into a side of the driven rollers, on a side of the plurality of driven rollers, and a plurality of idlers which support the wire on a side in which the wire and the belt are in contact with each other and assist feeding of the wire along a feeding direction of the belt in a free-rotation state. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view illustrating a wire bending apparatus employing a wire feeding unit according to one embodiment of the present disclosure. 
         FIG.  2    is a perspective view illustrating an idler and a driven roller according to one embodiment of the present disclosure. 
         FIG.  3    is a cross-sectional view illustrating the idler and the driven roller according to one embodiment of the present disclosure. 
         FIG.  4    is a side view illustrating the idler and the driven rollers according to one embodiment of the present disclosure. 
     
    
    
     Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     Hereinafter, specific embodiments of the present disclosure will be described in accordance with the following drawings, however, they are only exemplary embodiments of the disclosure, and the present disclosure is not limited thereto. 
     Descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness. Also, terms described in below are selected by considering functions in the embodiment and meanings may vary depending on, for example, a user or operator&#39;s intentions or customs. Therefore, definitions of the terms should be made on the basis of the overall context. 
     The spirit and scope of the disclosure are defined by the appended claims. The following embodiments are only made to efficiently describe the progressive technological scope of the present disclosure to those skilled in the art. 
     A wire feeding unit  100  and a wire bending apparatus  10  including the wire feeding unit  100  which will be described below are merely examples and thus the present disclosure is not limited to the disclosed examples. For example, driven rollers illustrated in  FIG.  1    include a first driven roller  151 , a second driven roller  152 , a third driven roller  153 , a fourth driven roller  154 , and a fifth driven roller  155 . The driven rollers are not limited to the above examples, and a smaller number of driven rollers may be provided. However, in the present disclosure, a plurality of driven rollers are provided to guide a feeding direction of a wire  1 . In this case, the feeding direction of the wire  1  may be from a side into which the wire  1  is drawn to a head portion  3  which bends or folds the wire  1 . 
     In addition, the configuration of the wire bending apparatus  10  will be described with reference to the wire feeding unit  100  including characteristics of the wire bending apparatus  10 . 
       FIG.  1    is a perspective view illustrating a wire bending apparatus  10  employing a wire feeding unit  100  according to one embodiment of the present disclosure. 
     Referring to  FIG.  1   , the wire bending apparatus  10  may include a wire inserter which is not illustrated, a wire feeding unit  100 , and a head portion  3 . The wire inserter feeds a wire  1  into the wire bending apparatus  10  in such a way to provide the wound wire  1 . For example, the wire inserter may be formed in a shape such as a hollow pipe through which the wire  1  can be inserted and penetrate. 
     In addition, the head portion  3  may be configured to bend or fold the wire  1  fed by the wire feeding unit  100 , which may be performed by determining a wire feeding speed, a feeding amount, and a time point of bending or folding under the control of a controller which is not illustrated. 
     In addition, the wire feeding unit  100  may include a driving motor  120  for generating a feeding power (driving force), a driving roller  130 , driven rollers  151 ,  152 ,  153 ,  154  and  155 , a belt  160 , an idler  170 , and an auxiliary roller  141  and  142 . Each configuration can be fixed at the fixing plate  110  by passing there through or by not passing there through. For example, a driving motor  120  may be positioned on one surface of the fixing plate  110  and a motor shaft of the driving motor  120  may be disposed to pass through the fixing plate  110 . 
     The motor shaft may be rotated in a form of coupling the driving roller  130  and the driving roller  130  has an outer circumferential surface to which a belt  160  is coupled, thereby rotating the belt  160 . Here, the coupling may be belt-pulley coupling in which a roller and the belt  160  are coupled to each other by a side inclination or coupling between teeth (S in  FIG.  2   ) formed on an outer circumferential surface of a roller and the belt  160  of a timing belt type. By the coupling, the driving force generated from the driving motor  120  makes the rotation speed and the feed amount of the wire  1  proportionally, so that the feed speed and the feed amount controlled by the control unit (not shown) may be realized. 
     The belt  160  may transfer the driving force of the driving motor  120  to the driven rollers  150  through the driving roller  130 . That is, the belt  160  may interlock the driving roller  130  and the driven rollers  151 ,  152 ,  153 ,  154  and  155 . Due to the interlocking, a rotation direction of the driven rollers  151 ,  152 ,  153 ,  154  and  155  may be determined according to a direction in which the driving roller  130  rotates. The rotation direction is determined as a direction in which the belt  160  is fed from a side into which the wire  1  is drawn to the head portion  3 . The belt  160  may be flexible enough to be curved along outer circumferential surfaces of the primary driving roller  130  and the driven rollers  151 ,  152 ,  153 ,  154  and  155 . The wire  1  may be contacted to an opposite surface of which teeth S are formed, which are coupled to the driving roller  130  and the driven rollers  150 , and be fed in a feeding direction (M in  FIG.  4   ). 
     Further, when the belt  160  is required to be installed or uninstalled due to aging or damage thereof, tension acting on the belt  160  may be released so that the belt  160  can be removed. The release of the tension may be performed by pressurization of the auxiliary roller  140 . In the same manner as in the driving roller  130  and the driven rollers  151 ,  152 ,  153 ,  154  and  155 , the auxiliary roller  140  may be in contact with an outer surface which the wire  1  is brought into contact with, rather than being in contact with an inner surface of the belt  160  where the teeth S are formed. In addition, there is no separate shape on the outer circumferential surface of the belt  160  so that it is possible that the belt  160  moves through the surface contact with the curved surface in the shape of the outer circumferential surface of the auxiliary roller  140 , and that the tension is provided to the belt  160 . 
     Specifically, a position of the auxiliary roller  140  may be selectively determined within a length of a slot hole formed in the fixing plate  110 . Accordingly, the position of the auxiliary roller  140  within the length of the slot hole may cause tension to be formed or released on the belt  160 . The belt  160  may be fed by the rotation of the driving roller  130  in a state in which the tension is formed, and the removal or the belt  160  may be performed in a state in which the tension is released. A position at which the auxiliary roller  140  is placed within the length can be selectively determined, and thereby it is possible to adjust the tension. 
     As described in the example of the present disclosure, the wire feeding apparatus  100  includes a plurality of driven rollers  151 ,  152 ,  153 ,  154  and  155 . There may be two or more points at which at least two driven rollers  151 ,  152 ,  153 ,  154  and  155  pressurize the wire  1  through the belt  160 , and an arbitrary direction formed by connecting the points may be a direction in which the wire  1  is guided. Therefore, a plurality of driven rollers  151 ,  152 ,  153 ,  154  and  155  have to be provided to form directionality. 
     Further, since the belt  160  is fed along the outer circumferential surfaces of the driven rollers  151 ,  152 ,  153 ,  154  and  155  and the driving roller  130 , the belt  160  may have flexibility. The surface friction formed between wire  1  and belt  160  having a predetermined level of softness may have at least one surface with a relatively high surface friction compared to between metal materials and wire  1  due to the softness, which may be a factor that can prevent slippage with the wire  1  in the course of contacting for feeding the wire  1 . Since the wire  1  is in the form of a fine wire, there is a limit in structurally increasing a contact area with the belt  160 , and thus the surface friction may be increased through a property of matter (softness). 
     By increasing the surface friction, a contactable surface area of between the wire  1  and the belt  160  may be secured, so that the wire  1  can be prevented from twisting in the course of feeding the wire  1 . The twisting of the wire  1  may mean that, in the case of the wire  1  being formed by twisting a plurality of fine wires, the wire  1  is rotated along a direction of twisting during feeding as the contact area with the configuration that feeds the wire  1 . Hence, by securing the contact area between the belt  160  and the wire  1 , rotating of the wire  1  may be prevented during feeding. 
       FIG.  2    is a perspective view illustrating an idler  170  and a driven roller  153  according to one embodiment of the present disclosure, and  FIG.  3    is a cross-sectional view illustrating the idler  170  and the driven roller  153  according to one embodiment of the present disclosure. 
     The third driven roller  153  among the driven rollers  151 ,  152 ,  153 ,  154  and  155  illustrated in  FIG.  1    will be described with reference to  FIG.  2   . As described above, a number of idlers  170  may be provided corresponding to the number of driven rollers  151 ,  152 ,  153 ,  154  and  155 , and the belt  160  may be interposed between each idler  170  and each driven roller  151 ,  152 ,  153 ,  154  and  155 . A distance between the belt  160  and the idler  170  does not exceed a diameter of the wire  1  (when the wire is circular-shaped). In the course of pressurizing and feeding the wire  1 , the idler  170  may be in a free-rotation state without being rotated and provided with separate power. For the free rotation, both ends of a rotation shaft A are connected to a base  4  and the idler  170  may be rotated about the rotation shaft A. 
     If the separate power is provided for the idler  170 , the idler  170  has to be rotated at a rotational speed corresponding to a feeding speed determined by the rotational speed provided by the driving motor  120 . In this case, when the rotational speed of the idler  170  does not correspond to the feeding speed of the belt  160  fed by the driving motor  120  and an error occurs, the wire  1  may slip during feeding and the amount or speed of wire  1  transferred to the head portion  3  may differ from information which is input in advance to the controller. The errors of the amount or speed of wire  1  bending or folding position of the wire  1  to be wrong. Thus, driving is performed by the single power source (driving motor  120 ) is used in order to avoid such possibility of error. 
     Meanwhile, referring to  FIG.  3   , the idler  170  has a guide groove  171  where the wire  1  can be seated to prevent the wire  1  from deviating in position in the course of feeding the wire  1 . The guide groove  171  may be formed to correspond to a surface shape of the wire  1 . For example, when the wire  1  has a diameter of 2 mm, a radius of the guide groove  171  may be formed as 1 mm, so that the shape of the guide groove  171  can correspond to the wire  1 . The shape of the guide groove  171  may be determined to maximize a contact area with the wire  1  in order to prevent the wire  1  from slipping from the idler  170 . The maximum value of the contact portion corresponds to half of the outer circumferential length of the wire  1 , and the guide groove  171  may be provided that half of the outer circumference can be contacted. 
     Further, a surface of the guide groove  171  may be soft as the belt  160 . The guide groove  171  having a predetermined elasticity may prevent slippage of the wire  1  through the surface friction. The guide groove  171  may be made of the same material as the soft belt to prevent slippage with the wire, or may be made of different material as the soft belt when the surface friction between the different material and wire  1  is formed higher than the surface friction between the metal material and the wire  1 . A cover portion  5  may be disposed according to the arrangement of the plurality of driven rollers  151 ,  152 ,  153 ,  154  and  155 . The cover portion  5  may be disposed on the base  4  and be positioned such that its maximum height from the base  4  is lower than the idler  170 . This may be a structure for avoiding interference with the wire  1  to be fed and a loss of feeding power may be prevented by avoiding the interference with the wire  1 . 
       FIG.  4    is a side view illustrating an idler  170  and driven rollers  152 ,  153  and  154  according to one embodiment of the present disclosure. 
     Referring to  FIG.  4    in conjunction with  FIG.  3   , the cover portion  5  may have an auxiliary guide  5 ′ formed in the form of a groove. The auxiliary guide  5 ′ may be formed on an extension of the guide groove  171  formed on the idler  170  with respect to the feeding direction M of the wire  1 . However, the auxiliary guide  5 ′ does not guide the wire  1  in the conveying direction M through the continuous contact during the conveyance of the wire  1 . When the wire  1  sags between the driven rollers  152 ,  153  and  154  or when the wire  1  deviates from some section, the auxiliary guide  5 ′ performs a guide function such that the wire  1  can be normally fed to the next idler  170  (fed to the guide groove  171 ). 
     According to one embodiment of the present disclosure, a configuration which is in direct contact with a wire is limited to a belt and an idler to reduce a contact area, thereby reducing resistance to a feeding direction, and an increase in contact area through the belt prevents twisting that occurs in the course of feeding the wire and accordingly the resistance in the feeding direction is reduced so that a loss of power due to friction can be prevented. 
     In addition, according to one embodiment of the present disclosure, a feeding power generated by one driving motor is provided as a feeding force, wherein the wire is fed through the contact between a belt that rotates by the feeding power and a freely rotatable idler so that slippage due to a difference in feeding speed can be prevented. 
     Also, according to one embodiment of the present disclosure, a guide groove in which a part of wire can be seated is formed on the idler that is brought into contact with the wire so that the wire can be prevented from deviating in position and thus a wire feeding apparatus with higher reliability can be provided. 
     A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.