MXPA98003712A - Method for high speed spin winding of a coil about a continuous lamination core - Google Patents

Abstract

A method for high speed spin winding a coil on a continuous lamination core. A two piece or hinged bobbin (26) having two flanges (30, 34) is placed around a leg of the transformer core (22) and snapped together. Both flanges include an outwardly facing surface which defines a concentric groove (46). One flange includes passages (54) for receiving printed circuit board terminating pins (58) which are installed prior to winding the coil. The other flange has a circumferential gear (30) located in its outwardly facing surface. The core with bobbin and terminating pins installed is placed into a spin winding fixture. A bobbin bearing (62) having a bearing surface including a circumferential ridge (74) is placed adjacent the outwardly facing surfaces of the two flanges (30, 34) such that the circumferential ridges (74) are partially received within the concentric grooves (46) of the outwardly facing surfaces of the two flanges (30, 34). A wire feeder terminates the leading end of the coil wire on one of the terminating pins (58). A drive gear engages the circumferential gear (30) on the flange and rotates the bobbin at high speed drawing wire from the wire feeder. The wire feeder moves back and forth between the two flanges to uniformly wind the coil wire on the bobbin. The wire feeder terminates the trailing end of the coil wire on the other terminating pin and then cuts the wire off. The terminating pins are pressed further into the flange until the desired length for printed circuit board connection extends outwardly from the opposite side of the flange.

Description

METHOD FOR ROLLING BY HIGH SPEED TURNING A COIL AROUND FROM A NUCLEUS OF CONTINUOUS LAMINATION Field of the Invention The present invention relates to the field of current transformers and particularly to a method for high-speed roll winding of a transformer coil with terminal pins of printed circuit board around a core of continuous rolling transformer. . BACKGROUND OF THE INVENTION As electronic technology advances, the need has increased for transformers capable of being mounted on easily manufactured, cheap, smaller printed circuit boards capable of providing power to the circuit board as well as detecting current in the circuit board. primary circuit. In order to provide power to the printed circuit board, the core of the transformer must have a high magnetic permeability and the coil must have a large number of turns of wire to provide the required voltage. The toroidal wound transformer has generally been the best choice for such a transformer, due to its precision and compact construction. However, the toroidly wound transformer involves a slow, expensive winding process. Less expensive alternatives to the toroidal transformer, such as two-piece, C-shaped or E-shaped laminated core transformers, or interlaced laminated core transformers, have air spaces in their cores that interrupt the magnetic flux in the core and therefore reduce the accuracy of the transformer. Using special materials that have high permeability and proper grain alignment of the material can reduce the interruption of magnetic flux in the core, but significantly increases the cost of the transformer. Another alternative is to use a rolling, continuous, or narrow magnetic core. This will eliminate the problem of the air gap, but requires winding the coil around a closed core leg. Providing a coil with enough turns to produce the voltage required to drive the circuit board can then become a problem. If a fine wire is not used for the coil, the number of turns needed to produce the required voltage will significantly increase the physical size of the transformer and thus prohibit mounting it on the printed circuit board. The high-speed winding of a coil of fine wire around a one-piece coil is not new. However, the construction of a piece in a transformer core in two pieces, in the form of a C or E, or an interlaced lamination core must be used. These nuclei have the problem of air space. The most desirable solution would be to wind a thin wire core around the leg of a continuous lamination core or closed magnetic core. This process is available, but has generally been limited to larger power transformers having coils consisting of relatively few turns of medium gauge wire or lath wire that must be wound at low speeds. Examples of this process can be found in U.S. Patent Nos. 2,305,999; 2,414,603 and 3,043,000. In recent years, the transformer industry has begun winding coils around continuous rolling cores or closed magnetic cores of smaller transformers. However, as seen in U.S. Patent Nos. 4,325,045; 4,638,545; and 5,515,597, the placement of the coil and the low winding speeds have restricted the efficiency of this winding process. All of the transformers described above involve several labor-intensive sub-assembly steps and do not provide means for simultaneously terminating the coil wire and connecting it to the printed circuit board. Therefore, it would be desirable to have a generally automated, less labor-intensive method of producing a transformer capable of mounting on a printed circuit board, low cost, precise, small, having a coil of fine wire wound by twist of high speed on a continuous lamination core or closed magnetic core.

Co-pending of the Invention The present invention provides a generally automated method for manufacturing a current transformer capable of mounting to a small, accurate, low-cost printed circuit board, having a coil of fine wire wound by high-speed spin on a continuous lamination core or closed magnetic core. The process involves placing a two-piece coil or split coil having two halves connected by an integral joint around a leg of the continuous rolling core and snapping together. The pre-assembly of the core laminations by welding, staking or riveting is not required. The coil includes first and second flanges separated by a tubular coil base. Each tab includes an external surface having a concentric slit. The first flange also includes a circumferential gear formed integrally from the outer surface such that a pulse gear can be linked to rotate the coil at high speed. The second tab includes passages to receive the coil termination pins. These pins are of sufficient length for direct connection to a printed circuit board and are installed before winding the coil. The end pins are supported in a support way through the second flange such that the midpoint of each terminal pin is coincident with the mating line of the two coil halves. This allows the coil and the inserted terminal pins to rotate freely around the core leg and inside the core window. The core of the transformer with the coil installed is placed in a winding attachment that holds the core to prevent movement during the winding process. Two coil bearings are moved to a position such that one is immediately adjacent to the outer surface of each of the two coil tabs. Each coil bearing includes a bearing surface having a circumferential spine configured to conform to and be partially received within the concentric slot of the coil tabs. The bearing surfaces of the spool bearings remain slightly spaced from the outer surfaces of the spool flanges. At the start of the coil winding process, a wire feeder wraps the guide end of the coil wire around one of the coil wire end pins. A traction wheel then links the engagement of the first coil flange and begins to rotate the coil at high speed, thus pulling the coil wire of the coil wire feeder as the coil rotates. The wire feeder guides the wire back and forth through the bobbin, producing a coil wound evenly. When it approaches the desired number of revolutions, the coil is quickly encouraged and stopped. The wire feeder wraps the trailing end of the coil wire around the other coil wire terminal and cuts the wire. The transformer is removed from the winding attachment and the wire terminal pins are further supported in addition to one side of the second coil flange such that the desired length of the end pin extends outwardly from the opposite side of the second flange. coil. When very thin coil wire is used, it may be desirable to strip the end ends of the coil wire, i.e. multiple wire strands are braided together for additional strength. It may also be desirable to form the terminating ends of the wire spirally around the end pins to prevent wire breakage upon re-positioning of the pins after winding. Other aspects and advantages of the invention will be apparent to those skilled in the art upon review of the following detailed description., the drawings and the claims. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded view of a solid or continuous lamination core and a two-part coil with terminal pins of printed circuit board in accordance with the present invention. Figure 2 is a side view of a transformer assembled with terminal pins of printed circuit board in the winding position according to the present invention.

Figure 3 is a side view of a transformer assembled with terminal pins of printed circuit board in the extended mounting position of the printed circuit board according to the present invention. Figure 4 is a cross-sectional view of a core leg with assembled spool and spool bearings in place. Figure 5 is an isometric view of the coil bearing, showing the bearing surface according to the present invention. Figure 6 is a top view of a three-phase transformer assembled in accordance with the present invention. Figure 7 is a front view of a three-phase transformer assembled in accordance with the present invention and electrically connected to a common printed circuit board by printed circuit card terminals. Figure 8 is an isometric view of a three-phase transformer carrier according to the present invention. Figure 9 is an exploded view of a three-phase transformer assembly with transformer carrier according to the present invention. Before an embodiment of the invention is explained in detail, it will be understood that the invention is not limited in its application to the details of construction and description or illustrated in the drawings. The invention is capable of other embodiments and of being implemented or carried out in various other ways. Likewise, it will be understood that the phraseology and terminology used herein are for description purposes and should not be considered as limiting. Description of the Preferred Embodiment Form Figure 1 illustrates an exploded view of a continuous rolling core transformer having a high speed rotating coil according to the present invention and generally indicated by the reference number 10. The transformer 10 it includes a continuous rolling core 14 having a window 18 defined by integral core legs 22. The core 14 may have a generally square or rectangular shape such that the window 18 defined by the core 14 also has a generally square or rectangular shape. The transformer 10 also includes a coil 26 installed around one of the core legs 22 on which the coil will be wound. The coil 26 can be made of two halves 28 which are assembled around one of the legs 22. The coil 26 can also be constructed in one piece molded having an integral hinge joining two halves in a similar manner. In the preferred embodiment, the coil halves 28 are provided with means integrally formed to be elastically adjusted together when installed on the core leg 22. The coil 26 includes a first flange 30, which is generally shaped circular, and a second flange 34, which is of a generally square shape. The first and second flanges, 30 and 34 respectively, extend outward from and generally perpendicular to a generally tubular coil base 38 separating the two flanges 30 and 34. The tubular coil base 38 defines a passage 40 having a diameter internal sized such that the coil 26 can rotate freely around the leg 22 of the transformer core 14. Each of the first and second flanges, 30 and 34 respectively, includes an outward facing surface 42. A concentric slot 46 having a bevelled inner surface 48 is defined on each of the outward facing surfaces 42. A circumferential gear 50 is also defined on the outward facing surface 42 of the first flange 30. The second flange 34 defines two passages 54 which generally they are parallel to each other and passing through the flange 34 such that a generally equal portion of each passage 54 is defined in each half 28 of the pe 34. Each of the passages 54 is sized to loosely receive a terminal pin 58 of printed circuit board that functions as a terminal for the coil wire and an electrical connection to a printed circuit board., as shown in Figure 5. The terminal pins 58 of the printed circuit board also help to secure together the two winding halves 28 during the coil winding process. The coil 26 is installed on the selected core leg 22 by placing a coil half 28 on one side of the selected core leg 22 and the other coil half 28 on the other side of the selected leg 22, such that the tabs 30 and 34 of each half 28 are properly aligned and then elastically adjusting the two halves 28 together. The passages 54 in each of the two halves 28 of the second flange 34 will be aligned such that they pass completely through the second flange 34. The core 14 with the coil 26 attached is placed in an attachment where a terminal pin 58 of the card of printed circuit board is supported in a manner that is tolerable towards each of the two passages 54. The terminal pins 58 of the printed circuit board are supported along their length during the insertion process to prevent ripple. When inserted properly, the midpoint of each terminal pin 58 of the printed circuit board should coincide with the mating line of the two coil halves 28, thereby allowing the coil 26 with the terminal pins 58 of the card. printed circuit boards rotate freely around the core leg 22 and inside the core window 18, as shown in figure 2. The core of the transformer 14 with the coil 26 installed is placed in a winding attachment, which holds firmly the core 14 to prevent movement during the winding process. As shown in Figure 4, two coil bearings 62 are positioned such that one is immediately adjacent to each of the outward facing surfaces 42 of each of the two coil tabs 30 and 34. As shown in FIG. shown in Figure 5, each of the spool bearings 62 has a relief 66, which is dimensioned to slidably receive a portion of the core of the transformer 14 immediately adjacent to the spool tabs 30 and 34. The reliefs 66 provide proper positioning of the bearings 62 with respect to the axis of the leg 22 around which the coil 26 will rotate. The relief 66 also helps to keep the non-assembled laminations of the core 14 in position during the winding process. Each bearing 62 also includes a bearing surface 70 which has an outwardly extending circumferential spine 74 with a beveled inner surface 76. The circumferential spines 74 are formed such that they are complementary to the concentric slits 46 in the flanges 30 and 34 The beveled inner surfaces 48 of the slits 46 and the beveled inner surfaces 76 of the ridges 74 help to center the coil 26 around the core leg 22. Each bearing surface 70 and its circumferential spine 74 is highly polished to reduce friction between the bearing surfaces 70 and the outward facing surfaces 42 of the flanges 30 and 34 during the high speed spinning winding process. When the spool bearings 62 are properly positioned, the circumferential ridges 74 will be centered around the axis of the core leg 22 and partially received within the concentric slots 46 of the spool flanges 30 and 34. A small space is maintained between the bearing surfaces 70 of the spool bearings 62 and the outward facing surfaces 42 of the spool flanges 30 and 34. The bearing surfaces 70 are provided with small gates 78 to discharge air at low pressure into the small space between the bearing surfaces 70 and the outward facing surfaces 42 of the coil tabs 30 and 34. The low pressure air flow acts both as a cooler for the bearing surfaces 70 and as a cushion between the bearing surfaces 70 and the outward facing surfaces 42 of the spool tabs 30 and 34 during the high speed spin winding process. When starting the coil winding process, a pulse gear links the circumferential gear 50 on the first flange 30 of the coil 26. The coil 26 is rotated to an index position where the terminal pins 58 are in a known position. As a fine coil wire is being wound on the coil 26, it is preferred that the guide and back ends be reinforced, i.e. multiple strands of wire are braided together for additional strength. The reinforcement is performed by a coil wire feeder which also terminates the guide end of the coil wire by wrapping the reinforced wire end around one of the terminal pins 58 of the printed circuit board. After finishing the coil wire, the coil wire feeder moves to the starting position on the coil base 38 as the impulse gear begins to rotate coil 26 at high speed. As the bobbin turns, bobbin wire is pulled from the bobbin wire feeder which moves back and forth between the first and second spool tabs, 30 and 34 respectively, thereby producing a coil wound in a uniform manner. As the desired number of revolutions approaches, the speed of the coil is quickly reduced to rest within a few revolutions. The wire feeder reinforces a portion of the terminating end of the coil wire, wraps the reinforced termination end around the other terminal pin 58 of the printed circuit board, and cuts the wire, leaving enough reinforced wire to finish the end guide the next coil to be wound. The transformer is removed from the winding attachment and the printed circuit card terminal pins 58 are supported in a supported manner towards one side of the winding flange 34 so that the desired length of the printed circuit board terminal pin 58 is extend outward from the opposite side of the second coil flange 34. Using this process, the time required to assemble the coil 26 in the core leg 22 and wind a coil of 8,000 turns of fine wire in the coil is approximately 90 seconds . As shown in Figures 6 and 7, a three-phase transformer can be made by taking three transformers 62, 66 and 70, each assembled in the same manner as the transformer 10 described above, and placing them side by side such that the core legs 22 adjacent to the coil 26 of the central transformer 66 overlap with the inner core legs 22 of the two external transformers 62 and 70. The overlapped legs 22 of the three transformer cores 14 are fixed together by means of mechanical fasteners such as rivets 74 or similar bras. In the preferred embodiment, a molded transformer carrier 78, as shown in FIGS. 8 and 9, will form the basis of a three-phase transformer assembly 82. The transformer carrier 78 is preferably made of an electrically insulating material and it defines three tubes 86 that will receive the electrical conductors of the primary circuit. The transformers 62, 66 and 70 are individually placed in the transformer carrier 78 such that the window 18 of each of the adjacent transformers 62, 66 and 70 receives one of the tubes 86. The transformer carrier also defines several stopped sleeves 90. , some of which will receive the printed circuit board terminals 58 when the transformers 62, 66 and 70 are placed in the transformer carrier 78. The overlapping core legs 22 of the transformers 62, 66 and 70 are riveted together simultaneously and the transformer carrier 78 by means of rivets 74, thereby forming the preferred three-phase transformer assembly 82. The transformer carrier 78 also includes a pair of generally parallel, integrally formed detents 94, each having an inwardly facing flange 98 at its distal end. The seals 94, in cooperation with the stopped sleeves 90, allow the transformer carrier 78 to be elastically attached to a printed circuit board 102. The detents 94 are received within a pair of holes 106 defined by the printed circuit board 102. such that the flanges 98 link one side of the printed circuit board 102 by linking the distal ends of the stopped sleeves 190 to the other side, thereby capturing the card 102 between the flanges 98 and the stopped sleeves 90. The printed circuit board 102 also defines holes 110 for receiving the tubes 86 by elastically adjusting the transformer assembly 82 on the printed circuit board 102. After elastically adjusting the transformer assembly 82 in place on the printed circuit board 102, more rivets are passed. lengths 114 through the laminations of the two external transformers 62 and 70, the stopped sleeves 90 and the printed circuit board 102. Al the electrical components are soldered by wave to the printed circuit board 102, the terminals 58 of the printed circuit board and the rivets 114 are also soldered to the printed circuit board 102, thereby securing the transformer assembly 82 to the card of printed circuit 102. It may also be desirable to place an adhesive between the transformer coils and the transformer carrier 78 for additional protection against vibration and shock.

Claims (3)

1. CLAIMS 1. A method of spinning a coil in a continuous rolling core, comprising the steps of: placing a coil around a leg of the transformer core, said coil having a first flange and a second flange which are generally parallel each other and spaced apart by a generally tubular coil base, each of said flanges having an outward facing surface, said first flange further including a circumferential gear on said outwardly facing surface; inserting two printed circuit board termination pins into said second tab of said spool, such that said pins are generally parallel to each other and extend an equal distance outward from opposite sides of said second flange; placing the transformer core with said coil and said printed circuit board termination pins installed therein towards a twist-up winding attachment; placing a coil bearing immediately adjacent each of said first and second flanges such that a bearing surface of said coil bearing is in a position juxtaposed with said facing surfaces facing away from said first and second flanges; terminating a guide end of a coil wire on one of said printed circuit board termination pins; linking said circumferential gear of said first flange with an impulse gear to produce high speed rotation of said spool; winding said coil wire evenly around said coil base between said first and second tabs when said coil is rotated; terminating a trailing end of said coil wire on the other of said printed circuit card terminating pins; pressing said printed circuit board termination pins further towards said second flange until the desired length extends outward from the opposite side of said second flange.
2. 2. A method of spinning a coil in a continuous rolling core, comprising the steps of: placing a coil around a leg of the transformer core, said coil having a first flange and a second flange which are generally parallel between and spaced apart from one another by a generally tubular coil base, each of said flanges further including an outward facing surface in which a concentric groove is defined, said first flange further including a circumferential gear on said facing surface. outside; inserting two printed circuit board termination pins into said second tab of said coil such that said pins are generally parallel to each other and extend an equal distance outward from opposite sides of said second flange; placing the transformer core with said coil and said printed circuit board termination pins installed therein towards a twist-roll anchor; placing a coil bearing having a circumferential spine immediately adjacent said facing surfaces facing each of said first and second tabs, such that said circumferential spines are partially received within said concentric slits of said surfaces which they look out; terminating a guide end of a coil wire on one of said printed circuit board termination pins; linking said circumferential gear of said first flange with an impulse gear to produce high speed rotation of said spool; winding said coil wire evenly around said coil base between said first and second tabs when said coil is rotated; finish one rear end of said coil wire on the other of the printed circuit board termination pins; pressing said printed circuit board termination pins further toward said second tab until a desired length extends outwardly from the opposite side of said second tab.
3. 3. A method of spinning a coil in a continuous rolling core, comprising the steps of: placing a coil around a leg of the transformer core, said coil having a first flange and a second flange which are generally parallel between and spaced apart from one another by a generally tubular coil base, each of said flanges further including an outward facing surface in which a concentric groove is defined, said first flange further including a circumferential gear on said facing surface. outside; supportingly inserting two printed circuit board termination pins into said second flange of said reel, such that said pins are generally parallel to each other and extend an equal distance outwardly from opposite sides of said second flange; placing the transformer core with said coil and said printed circuit board termination pins installed therein towards a twist-roll anchor; placing a coil bearing having a circumferential spine immediately adjacent said facing surfaces facing away from each of said first and second tabs, such that said circumferential spines are partially received within said concentric slits of said surfaces which they look out; reinforce a guide end of a coil wire; terminating said reinforced guide end of said coil wire on one of said printed circuit board termination pins; linking said circumferential gear of said first flange with an impulse gear to produce high speed rotation of said spool; winding said coil wire evenly around said coil base between said first and second tabs when said coil is rotated; reinforcing a rear end of said core wire; terminating said reinforced rear end of said coil wire on the other of said printed circuit board termination pins; pressing said printed circuit board termination pins further towards said second flange until the desired length extends outward from the opposite side of said second flange. Summary A method for high-speed roll winding of a coil in a continuous rolling core. A two-piece or articulated coil (26) having two flanges (30, 34) is placed around a leg of the transformer core (22) and elastically adjusted together. Both tabs include an outward facing surface, which defines a concentric groove (46). A tab includes passages (54) for receiving printed circuit board termination pins (58) that are installed before winding the reel. The other flange has a circumferential gear (30) located on its surface facing outwards. The core with the coil and the termination pins installed is placed on a roll-up attachment. A coil bearing (62) having a bearing surface including a circumferential spine (74) is positioned adjacent to the outward facing surfaces of the two tabs (30, 34) such that the circumferential spines (74) are received from Partially within the concentric grooves (46) of the facing surfaces facing away from the two flanges (30, 34). A wire feeder terminates the guide end of the coil wire on one of the termination pins (58). An impulse gear links the circumferential gear (30) in the flange and rotates the coil at high speed, pulling wire from the wing-feeder. The wire feeder moves back and forth between the two tabs to uniformly wind the coil wire in the coil. The wire feeder ends the rear end of the coil wire on the other termination pin and then cuts the wire. The termination pins are further depressed towards the flange until the desired length for the printed circuit card connection extends outward from the opposite side of the flange.