Patent Publication Number: US-2012025941-A1

Title: Iron-core coil assembly

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 99214405 filed in Taiwan, R.O.C. on 2010/7/28, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to an iron-core coil assembly, and more particularly to an iron-core coil assembly formed by arranging a groove and U-shaped wires on a substrate, and embedding an iron-core device into the groove. 
     2. Related Art 
     An iron-core coil assembly is generally used to fabricate an electronic device or apparatus, such as an inductor, an electrical transformer, and a common mode choke. The traditional process for fabricating the iron-core coil assembly includes winding a wire having an insulating layer coated on its surface (for example, enameled wire), onto a specific winding area of an iron-core device. In order to lower the leakage inductance and magnetic flux loss, a closed (ring-shape), iron-core device must be used in most cases, which not only solves the leakage inductance and magnetic flux loss problems mentioned previously, but also avoids interference caused by the introduction of external magnetic lines of force into the iron-core device. However, the difficulty involved in winding wire onto the surface of the closed iron-core device is also increased greatly. 
     Furthermore, the enameled wires used by the traditional winding machine dedicated to wind a wire (enameled wire), onto the surface of an iron-core device are limited by diameter, since slender enameled wire which is too thin can easily break during the winding process. Where the diameter of the enameled wire cannot be reduced any further, the size of the iron-core coil assembly is accordingly limited, and further miniaturization becomes difficult. 
     In order to solve the difficult winding problem of the closed iron core, in the prior art a combined iron core is used, that is, an iron core is divided into two or a plurality of parts, which are joined together after winding. However, using such a method the enameled wire must also be wound circle by circle on the winding area of the iron-core device manually or with the aid of a machine, which not only prolongs the preparation process unnecessarily, but also leads to a lowered inductance value of the whole iron-core coil assembly due to non-uniform surfaces (junction), formed by joining the iron cores. 
     The problems related to winding and the difficulties of further miniaturization of the conventional iron-core coil assembly are therefore expected to be solved by persons of skill in the art. 
     SUMMARY OF THE INVENTION 
     In view of the problems in the prior art, the present invention is directed to an iron-core coil assembly which includes a substrate, a plurality of U-shaped wires, a first pin, a second pin, and an iron-core device. The substrate has a groove divided into a winding area and a non-winding area. The plurality of U-shaped wires is disposed in the winding area, with the wires separated from each other, each U-shaped wire has an opening and a recess, and the recess is located in the groove. The first pin and the second pin are respectively arranged at two ends of the opening. The iron-core device is disposed in the groove, and passes through the recess of each U-shaped wire. 
     Therefore, depending on the size of the desired inductance value, a certain number of U-shaped wires are interposed (molded) in at least one winding area of the groove in advance with the opening facing upward, the iron-core device having a closed magnetic loop is placed in the groove, such that the iron-core device passes through the recess of each U-shaped wire, thereby modifying the inconvenience caused by the necessary winding of the iron-core device circle by circle in the prior art. 
     Since use of a winding machine is no longer necessary, the size of the iron-core coil assembly is not limited by a winding machine, and thus can be miniaturized further. 
     As described above, the present invention solves the problems related to winding and difficulty of further miniaturization in the prior art. The embodiments of the present invention and effects thereof are described below with reference to drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus not limitative of the present invention, wherein: 
         FIG. 1  is an exploded view of a first embodiment according to the present invention; 
         FIG. 2  is a combined view ( 1 ) of the first embodiment of the present invention; 
         FIG. 3  is a combined view ( 2 ) of the first embodiment of the present invention; 
         FIG. 4  is a schematic view ( 1 ) of a connection portion according to the first embodiment of the present invention; 
         FIG. 5  is a schematic view ( 2 ) of the connection portion according to the first embodiment of the present invention; 
         FIG. 6  is a schematic view ( 1 ) of a connection portion according to a second embodiment of the present invention; 
         FIG. 7  is a schematic view ( 2 ) of the connection portion according to the second embodiment of the present invention; 
         FIG. 8  is an exploded view of a third embodiment of the present invention; 
         FIG. 9  is a combined view ( 1 ) of the third embodiment of the present invention; 
         FIG. 10  is a combined view ( 2 ) of the third embodiment of the present invention; 
         FIG. 11  is a schematic view ( 1 ) of a connection portion according to the third embodiment of the present invention; 
         FIG. 12  is a schematic view ( 2 ) of the connection portion according to the third embodiment of the present invention; 
         FIG. 13  is an exploded view of a fourth embodiment of the present invention; 
         FIG. 14  is a combined view ( 1 ) of the fourth embodiment of the present invention; and 
         FIG. 15  is a combined view ( 2 ) of the fourth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-3  are respectively an exploded view, a combined view ( 1 ) and a combined view ( 2 ) of a first embodiment of the present invention. Please refer to  FIGS. 1-3 , in which the first embodiment of the present invention includes a substrate  11 , a plurality of U-shaped wires  12 , and an iron-core device  13 . The substrate  11  has a groove  111  divided into a winding area  112  and a non-winding area  113 . The U-shaped wires  12  are disposed in the winding area  112  at a fixed space, each U-shaped wire has an opening  123  and a recess  124 . A first pin  121  and second pin  122  are respectively arranged at two ends of the opening  123 , and the recess  124  is located in the groove  111 . The iron-core device  13  is disposed in the groove  111 , and passes through the recess  124  of each U-shaped wire  12 . As such, a coil surrounding the iron-core device  13  can be formed just by electrically connecting the first pin  121  of the U-shaped wire  12  to the second pin  122  of the abutting U-shaped wire  12 . When more first pins  121  of the U-shaped wires  12  are electrically connected to the second pins  122  of the abutting U-shaped wires  12 , turn number of the coils surrounding the iron-core device  13  can be increased, thereby improving an inductance value of an iron-core coil assembly  1 . 
     This embodiment is especially suitable as an inductor device, in which the used iron-core device  13  is closed, and has low magnetic flux loss property, and a U-shaped slot may be further arranged in the winding area  112  of the groove  111 , so as to firmly dispose the U-shaped wires  12  in the winding area  112 . 
       FIGS. 4-5  are respectively a schematic view ( 1 ) and a schematic view ( 2 ) of a connection portion according to the first embodiment of the present invention. Please refer to  FIGS. 4-5 , in which embodiment the first pin  121  of the U-shaped wire  12  is indirectly electrically connected, through a connection portion  14  on a printed circuit board (PCB)  19 , to the second pin  122  of the abutting U-shaped wire  12 . The connection portion  14  is coupled to the U-shaped wires  12 , and has a plurality of first pin positions  141  and a plurality of second pin positions  142 , in which the plurality of first pin positions  141  is individually electrically connected to the first pins  121  of the plurality of U-shaped wires  12 ; and the plurality of second pin positions  142  is individually electrically connected to the second pins  122  of the plurality of U-shaped wires  12 . Furthermore, this embodiment further includes a plurality of first lines  15  disposed in parallel at a space from each other, in which the two ends of each first line  15  are respectively electrically connected to the first pin position  141  and the second pin position  142  next to the first pin position  141 . In this way, the U-shaped wire  12  may electrically communicate with the abutting U-shaped wire  12  and thus form a coil structure surrounding the iron-core device  13  by the bridging of the connection portion  14  and the first line  15 , in which an electrical signal is input from a first signal contact  143 , and output from a second signal contact  144 , or vice versa. 
       FIGS. 6-7 , are respectively a schematic view ( 1 ) and a schematic view ( 2 ) of a connection portion according to a second embodiment of the present invention. Please refer to  FIGS. 6-7 , which embodiment is different from the first embodiment by virtue of the different wiring means of the first lines  15 . By altering the wiring means of the first lines  15 , a plurality of U-shaped wires  12  and the first lines  15  are separated into two independent coil structures, and the U-shaped wires  12  and the first lines  15  contained in each coil structure are connected in series to each other to form a single circuit loop. In one coil structure, an electrical signal is input from a first signal contact  143 , and output from a second signal contact  144 ; and in the other coil structure, an electrical signal is input from a third signal contact  145 , and then output from a fourth signal contact  146 . A dot line in  FIG. 7  indicates a connection relation between the U-shaped wires  12  and the first lines  15  when an iron-core coil assembly  1  and a connection portion  14  are combined in this embodiment. In this embodiment, the two coil structures have the same number of the U-shaped wires  12  and the first lines  15 ; however, the two coil structures also can be designed as desired, so as to have different numbers of the U-shaped wires  12  and the first lines  15 . Moreover, in this embodiment center taps  18  are respectively arranged on the connection portion  14  for the two coil structures. 
       FIGS. 8-10  are respectively an exploded view, a combined view ( 1 ) and a combined view ( 2 ) of a third embodiment of the present invention. Please refer to  FIGS. 8-10 , in which the main difference between this embodiment and the first embodiment is a substrate  11  having two grooves  111  and two iron-core devices  13 . As shown in  FIGS. 11-12 , similar to the above embodiments, the U-shaped wires  12  of this embodiment can also form a coil structure surrounding the iron-core device  13  by connecting U-shaped wires  12  coupled to a connection portion  14  and a plurality of first lines  15 . 
       FIGS. 13-15  are respectively an exploded view, a combined view ( 1 ) and a combined view ( 2 ) of a fourth embodiment of the present invention. Please refer to  FIGS. 13-15 , in which the main difference between this embodiment and the first embodiment is a groove  111  which may be divided into two winding areas  112  and two non-winding areas  113 . In this embodiment, the number of U-shaped wires  12  in the two winding areas  112  is different, but may be designed to be identical as desired. 
     While the present invention has been described by the way of example and in terms of the preferred embodiments, it is to be understood that the invention need not to be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.