CN112823401A

CN112823401A - Transformer and method for manufacturing the same

Info

Publication number: CN112823401A
Application number: CN201980067018.4A
Authority: CN
Inventors: 尹晃锡
Original assignee: Mst Technology Co ltd
Current assignee: Maishiteng Technology Shandong Co ltd
Priority date: 2018-12-28
Filing date: 2019-12-27
Publication date: 2021-05-18
Anticipated expiration: 2039-12-27
Also published as: CN112823401B; WO2020138993A1

Abstract

The present invention relates to a transformer and a method for manufacturing the same, the transformer comprising: an inner frame (100); an outer molded frame (200) coupled to the inner frame (100); and a core portion (310, 320) coupled to the outer molded frame (200), the outer molded frame (200) including: an outer frame (210); a secondary coil (250) wound around the outer bobbin (210); and a molding part (220) formed by combining molding materials with the outer frame (210) through an insert molding manner, the invention has the advantages that the insulation of the primary coil and the secondary coil is strengthened, the insulation performance is improved, and the structural stability is also improved.

Description

Transformer and method for manufacturing the same

Technical Field

The present invention relates to a transformer and a method for manufacturing the same, and more particularly, to a winding insert injection molding integrated transformer in which a bobbin of a winding coil is insert molded to integrate a winding with the bobbin, and a method for manufacturing the same.

Background

Transformers are used to vary the current, voltage or matching resistance or separation circuit etc.

The transformer includes a primary coil and a secondary coil that are magnetically coupled, and the basic principle of the transformer is that if a current flows in the primary coil, the current will also flow in the secondary coil by the electromagnetic induction phenomenon. The ratio of the voltage of the primary coil to the voltage of the secondary coil transmitted corresponds to the ratio of the number of windings of the winding coil.

In particular, a transformer used as a voltage supply device varies a voltage in various ways to supply a required voltage to an apparatus to operate, and thus the transformer is an essential important component of an electronic apparatus.

Such a transformer prevents mutual interference between the primary coil and a power source flowing in the primary coil, and prevents noise or surge voltage on the primary coil side, and the primary coil and the secondary coil should be insulated in order to protect equipment from lightning strike or the like.

However, the conventional transformer has a problem in that the size of the transformer increases because it is necessary to secure an insulation distance because insulation is achieved only by a method in which the primary coil and the secondary coil are not electrically connected, and thus it is necessary to increase the thickness of the inner coil around which the primary coil is wound and the outer coil around which the secondary coil is wound.

Disclosure of Invention

Technical problem

The present invention aims to provide a transformer and a method for manufacturing the same, in which insulation between a primary coil and a secondary coil is enhanced, insulation performance is improved, structural stability is improved, and performance is improved.

Another object of the present invention is to provide a transformer and a method of manufacturing the same, in which insulation voltage between a primary coil and a secondary coil is enhanced while maintaining a stable winding, so that insulation performance can be greatly improved, noise can be improved, and a process is simplified.

Another object of the present invention is to provide a transformer having improved withstand voltage characteristics and a method for manufacturing the same.

Technical scheme

According to the features of the present invention for achieving the above object, the present invention comprises: an inner skeleton; an outer molded frame combined with the inner frame; a core portion coupled to the outer molded bobbin and including a primary coil wound around the inner bobbin, the outer molded bobbin including: an outer skeleton; a secondary coil wound around the outer bobbin; and a molding part formed by combining a molding material with the outer frame by insert molding, so as to prevent the secondary coil wound around the outer frame from being exposed to the outside and to lead out an end of the secondary coil to the outside.

A plurality of lead-out grooves are formed in the outer bobbin, the secondary coil is inserted into the lead-out grooves, and an end portion of the secondary coil is led out to an upper portion of the outer bobbin.

The lead-out groove is bent, and an opening inlet is formed on one side of the lead-out groove.

A fixing portion is formed in the drawing groove at a position adjacent to the inlet, and an end portion of the coil drawn along an upper portion of the outer bobbin is engaged with the fixing portion and fixed.

The molded part has a terminal guide groove formed in one side surface thereof, and an end of the coil drawn out is arranged in the terminal guide groove and is guided to a lower end of the molded part.

A reinforcing pin is disposed in the terminal guide groove.

The invention also comprises a tail-closing part which covers the terminal guide groove.

The molding part includes a support portion for supporting the inner frame coupled to the outer frame.

Support grooves or protruding ribs are formed in the support portion, and protruding ribs or support grooves corresponding to the support grooves or protruding ribs are formed in the inner frame.

The outer frame and the forming portion form a stepped joint surface.

The invention comprises the following steps: forming a framework; and a core portion combined with the molding frame, the molding frame including: an inner skeleton; a primary coil wound around the inner bobbin; an outer frame coupled to the inner frame; a secondary coil wound around the outer bobbin; and a simultaneous molding part formed by combining a molding material to the outer bobbin combined with the inner bobbin by insert molding, so as to prevent the secondary coil wound around the outer bobbin from being exposed to the outside and to draw an end of the secondary coil to the outside.

The molding frame includes a molding portion formed by joining a molding material to the inner frame by insert molding, so as to prevent a primary coil wound around the inner frame from being exposed to the outside and to expose a terminal connected to the primary coil to the outside.

The simultaneous forming part fills a space between the inner frame and the outer frame.

The inner frame is formed with an injection groove, and the molding material is injected through the injection groove so that the simultaneous molding part fills a space between the inner frame and the outer frame.

The transformer manufacturing method of the invention comprises the following steps: forming an inner frame, forming a core combining hole on the inner frame; forming an outer frame, in which a frame coupling hole is formed; a step of winding a primary coil around the inner bobbin; a step of winding a secondary coil around the outer bobbin; and forming an end of the secondary coil as a terminal.

The step of forming the end of the secondary coil as a terminal includes: a part of the end of the secondary coil is immersed in a lead solution to remove the outer layer and form a terminal pin.

The step of immersing a part of the end of the secondary coil in a lead solution to remove the outer skin and form the terminal pin includes: and a terminal pin formed by adding a reinforcing pin to a part of the end of the secondary coil, immersing the secondary coil in a lead solution to remove the outer skin, and forming a part of the end of the secondary coil integrally with the reinforcing pin.

Before the step of forming the end of the secondary coil as a terminal, the method includes: and a molding portion formed by insert molding a molding material between the outer bobbin and the secondary coil, the molding portion being coupled to the outer bobbin so as to prevent the secondary coil wound around the outer bobbin from being exposed to the outside and to expose an end portion of the secondary coil to the outside.

The method further includes, before the step of forming the end of the secondary coil as a terminal, the step of coupling the outer bobbin to the inner bobbin, and after the step of coupling the outer bobbin to the inner bobbin, the method includes: and a molded part formed by insert molding a molding material between the outer bobbin and the secondary coil, the molded part being coupled to the outer bobbin and the inner bobbin so as to prevent the secondary coil wound around the outer bobbin from being exposed to the outside and to allow an end of the secondary coil to be drawn out to the outside.

The method further includes, before the step of forming the end of the secondary coil as a terminal, the step of coupling the outer bobbin to the inner bobbin, and before the step of coupling the outer bobbin to the inner bobbin, the method includes: the inner bobbin and the primary coil are insert-molded to form a molded part coupled to the inner bobbin and the primary coil, so that the primary coil wound around the inner bobbin is prevented from being exposed to the outside and a terminal connected to the primary coil is exposed to the outside.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention has an effect that the outer molded bobbin surrounds the secondary coil by insert molding, and therefore, the insulation between the primary coil and the secondary coil of the inner bobbin is enhanced while maintaining a stable winding, and the thickness of the periphery of the coil (the thickness of the outer molded bobbin and the thickness of the inner bobbin) can be designed to be thin.

Therefore, the present invention has the effect of reducing the volume, enhancing the insulation performance, improving the performance of the transformer, and enhancing the moisture resistance by completely sealing the primary coil and the secondary coil, thereby improving the reliability of the product, compared to a general transformer.

Also, the present invention has an effect that the end of the secondary coil is immersed in the lead solution to form the terminal pin and used as the second terminal, and therefore, the problem of poor contact due to soldering can be prevented.

Further, the present invention has an effect that the molded frame in which the inner frame and the outer frame are integrated is formed by insert molding in a state in which the inner frame is joined to the outer frame, and therefore, the assembly is simple, the manufacturing process is simple, and the productivity can be improved.

Further, the present invention has an effect that the strength of the inner frame is reinforced by molding the inner frame, thereby improving the pressure resistance.

Drawings

Fig. 1 is a perspective view showing a transformer of a first embodiment of the present invention from the front.

Fig. 2 is an exploded perspective view showing a transformer according to a first embodiment of the present invention.

Fig. 3 is a perspective view showing an inner frame of the first embodiment of the present invention.

Fig. 4 is a perspective view showing an outer frame of the first embodiment of the present invention.

Fig. 5 is a perspective view showing an outer molded frame formed by insert molding the outer frame of the first embodiment of the present invention.

Fig. 6 is a perspective view showing the bottom surface of fig. 5.

Fig. 7 is a perspective view showing a state in which the secondary coil end portion of fig. 5 is formed as a terminal pin and arranged in a terminal guide groove.

Fig. 8 is a perspective view showing a state in which the terminal guide groove of fig. 7 is terminated by epoxy resin.

Fig. 9 is a view showing a section a-a of fig. 1.

Fig. 10 is a partial perspective view showing a state in which a part of the inside is cut away in a state in which the outer molded frame is combined with the inner frame according to the first embodiment of the present invention.

Fig. 11 is a view for explaining a process of manufacturing the inner frame of the first embodiment of the present invention.

Fig. 12 is a view for explaining a process of manufacturing the outside molded skeleton according to the first embodiment of the present invention.

Fig. 13 is a perspective view showing the transformer of the first embodiment of the present invention from the bottom surface.

Fig. 14 is a perspective view showing a transformer of a second embodiment of the present invention from the front.

Fig. 15 is a perspective view showing a transformer of a second embodiment of the present invention from the bottom surface.

Fig. 16 is a perspective view showing an inner frame of the second embodiment of the present invention.

Fig. 17 is a perspective view showing an outer frame of the second embodiment of the present invention.

Fig. 18 is a perspective view showing a state before ending terminal guide grooves in the molded frame of the second embodiment of the present invention.

Fig. 19 is a perspective view showing a closing portion closing the terminal guide groove in the molded frame according to the second embodiment of the present invention.

Fig. 20 is a flowchart showing a state of manufacturing the inner frame of the second embodiment of the present invention.

Fig. 21 is a flowchart showing a state in which a molded frame is manufactured using the inner frame and the outer frame of the second embodiment of the present invention.

Fig. 22 is a view showing a section a-a of fig. 14.

Fig. 23 is a partial perspective view showing a state where the core is removed along a-a section of fig. 14.

Fig. 24 is a flowchart showing a state of manufacturing the inner molded frame of the third embodiment of the present invention.

Fig. 25 is a flowchart showing a state in which a molded frame is manufactured using an inner molded frame and an outer frame of the third embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

The invention will be illustrated in three examples as follows: in the first embodiment, the outer frame is formed and combined with the inner frame; a second embodiment, the inner skeleton and the outer skeleton are combined and then simultaneously molded; and a third embodiment in which the inner frame is molded and simultaneously molded after being combined with the outer frame.

The first and second embodiments are for providing a transformer with improved withstand voltage, improved insulation performance, and improved structural stability, and the third embodiment is for forming an inner bobbin in order to further improve withstand voltage characteristics.

The transformers of the first to third embodiments may be used to change current, voltage, or matching resistance or discrete circuits, etc.

First embodiment

As shown in fig. 1 and 2, a transformer 10 according to a first embodiment of the present invention includes an inner bobbin 100, an outer molded bobbin 200, and

cores

310 and 320. The inner bobbin 100 and the outer mold bobbin 200 serve to physically and firmly wind and electrically insulate the primary coil 150 and the secondary coil 250.

The

terminals

160, 260 are located at the lower ends of both sides of the inner frame 100 combined with the outer molded frame 200. The

terminals

160, 260 include: a first terminal 160 connected to the primary coil 150 wound around the inner bobbin 100, serving as an input terminal; and a second terminal 260 connected to the secondary coil 250 wound around the outer mold frame 200 to serve as an output terminal. The primary coil 150 and the secondary coil 250 may use copper wire (copper).

The

core portions

310 and 320 are coupled to the outer mold frame 200, and the outer mold frame 200 is coupled to the inner frame 100. The

cores

310, 320 form a magnetic circuit electromagnetically coupled to the primary coil 150 and the secondary coil 250. The

cores

310, 320 are formed of a ferromagnetic substance having a strong magnetic flux. The ferromagnetic substance may be ferrite.

As shown in fig. 2 and 3, the primary coil 150 is wound around the inner bobbin 100. The inner bobbin 100 is provided with a first terminal 160 for electrical connection with the primary coil 150.

As shown in fig. 3, the inner bobbin 100 includes a winding portion 101 around which the primary coil 150 is wound and a core coupling hole 102 vertically penetrating the center of the winding portion 101. The inner frame 100 includes an upper end flange 130 and a lower end flange 104, the upper end flange 103 is formed to extend in the outer diameter direction at the upper end of the winding portion 101, and the lower end flange 104 is formed to extend in the outer diameter direction at the lower end of the winding portion 101. The upper end flange 103 and the lower end flange 104 may have, as basic shapes, a rectangular shape in which the core coupling hole 102 is formed at the center and a shape in which semicircles are further attached at both ends in the length direction of the rectangular shape.

As shown in fig. 2 and 3, the lower end flange 104 is further formed with an extension flange 105 on one side, and the extension flange 105 is provided with a first terminal 160. The first terminal 160 has a shape in which a predetermined number of terminal pins are arranged at predetermined intervals. The first terminals 160 may be inserted and fixed into insertion holes 106 formed at predetermined intervals in the extension flange 105. In a state where the terminal pin is adhered with the adhesive, the first terminal 160 is inserted into and coupled to the insertion hole 106, and thus can be firmly fixed to the extension flange 105. The end of the primary coil 150 wound around the winding part 101 may be connected to the first terminal 160 fixed to the insertion hole 106 by welding.

The inner frame 100 is provided with a protruding rib 107 at the upper end flange 103. The protruding rib 107 is formed to protrude from the upper surface of the upper end flange 103, and two protruding ribs 107 may be provided along both sides with the core coupling hole 102 therebetween. The protruding rib 107 corresponds to a support groove (reference numeral 226 in fig. 6) formed in a support portion (reference numeral 225 in fig. 6) of the outer mold frame 200, which will be described later, and serves to stably couple the inner frame 100 to the outer mold frame 200.

Preferably, the inner frame 100 is formed by injection molding, and is formed of an insulating resin. The inner frame 100 may be formed of a material having high heat resistance and high voltage resistance. For example, the inner frame 100 may use a PBT material to ensure insulation performance of 20kv/mm or more.

As shown in fig. 2, the outer mold frame 200 includes a secondary coil 250. The outer mold frame 200 includes a second terminal 260 for electrical connection of the secondary coil 250. The outer mold frame 200 is a structure in which the secondary coil 250 is shielded from the outside.

The outer molded frame 200 includes: an outer skeleton 210; secondary coil 250 wound around outer bobbin 210; and a molding part 220 formed by coupling a molding material to the outer bobbin 210 by insert molding, so as to prevent the secondary coil 250 wound around the outer bobbin 210 from being exposed to the outside and to draw an end of the secondary coil 250 to the outside.

The secondary coil 250 is interposed between the outer bobbin 210 and the molding part 220, and is insulated from the outside. Insert molding is to integrally form the outer frame 210 as a primary injection product and the molding part 220 as a secondary injection product by putting the outer frame 210 as a primary injection product into a mold and performing secondary injection.

As shown in fig. 4, the outer frame 210 includes: a coil winding portion 211 around which the secondary coil 250 is wound; and a bobbin coupling hole 212 vertically penetrating the center of the coil winding portion 211. The outer bobbin 210 includes an upper flange 213 and a lower flange 214 that are formed by expanding in the outer diameter direction at the upper and lower ends of the coil winding portion 211. Secondary coil 250 is wound around coil winding portion 211 formed between upper flange 213 and lower flange 214.

The portions of the coil winding portion 211 connected to the upper and

lower flanges

213 and 214 are formed in an arc shape (form an R-angle) to improve withstand voltage. The withstand voltage is a level that does not explode but is tolerated when a high voltage is applied. The formation of the R-angle removes the internal voids after the insert molding, thereby having an effect of improving the withstand voltage based on the strength reinforcement.

The outer frame 210 includes a lead-out groove 215 and a fixing portion 216.

The lead-out groove 215 is a groove for leading out each end of the secondary coil 250 wound around the coil winding portion 211 from the coil winding portion 211 to an upper portion of the upper flange 213. The drawing groove 215 is formed in the upper flange 213 so as to be recessed in the rear end direction, and a plurality of the drawing grooves 215 are opened vertically. The secondary coil 250 is inserted into the lead-out groove 215, and the end of the secondary coil 250 inserted into the lead-out groove 215 is led out to the upper portion of the outer bobbin 210.

The fixing portions 216 are arranged at predetermined intervals at respective ends of the secondary coil 250 drawn out to the upper portion of the upper flange 213. The fixing portion 216 is disposed at the inlet of the lead-out groove 215 so that the inlet of the lead-out groove 215 and the end of the lead-out groove 215 are at a position shifted from each other, and the end of the secondary coil 250 is caught by the fixing portion 216. The fixing portion 216 has a C-shaped groove that can fix the position of the end of the secondary coil 250 wound around the coil winding portion 211.

The plurality of fixing portions 216 are formed on one side of the upper flange 213 of the outer bobbin 210, and fix end positions of the secondary coil 250. The fixing portions 216 are arranged at predetermined intervals, and can maintain an insulation distance between the end portions 250a of the secondary coils serving as the terminal pins. The number of the lead grooves 215 and the fixing portions 216 is 2 times the number of the coils wound around the coil winding portion 211.

The end 250a of the secondary coil is inserted into the lead-out groove 215, is caught by the fixing portion 216, and is placed in the C-shaped groove of the fixing portion 216 to be fixed. Therefore, the drawing groove 215 is curved so that the positions of the inlet and the end are shifted, and the end of the drawing groove 215 and the fixing portion 216 are arranged on a straight line.

As shown in fig. 5, when outer frame 210 is set in a mold and insert-molded, outer molded frame 200 is formed in which outer frame 210 is coupled to molding portion 220. Secondary coil 250 wound around coil winding portion 211 of outer bobbin 210 is surrounded by molded portion 220 and is not exposed to the outside. Further, the end of the secondary coil 250 wound around the outer bobbin 210 is drawn out to the outside through one side upper end corner of the outer molding bobbin 200. The end portion 250a of the secondary coil drawn to the outside through the one upper end corner of the outer mold frame 200 is drawn in a state of being aligned at a predetermined interval by the fixing portion 216 at the position of the aligned end portion 250a of the secondary coil. When secondary coil 250 is wound around outer bobbin 210 and insert-molded to form the outer molded bobbin 200, the thickness uniformity can be ensured.

The outer molded frame 200 is provided with terminal guide grooves 221 on side surfaces (see fig. 2 and 7). The terminal guide groove 221 is formed in the side of the outer mold frame 200 including the corner from which the end 250a of the secondary coil is drawn. The terminal guide grooves 221 are formed in a concave shape along the vertical direction, and a plurality of the terminal guide grooves 221 are formed at predetermined intervals. The end portion 250a of the secondary coil drawn out to the outside from the one-side upper end of the outer mold frame 200 is placed at the one-side lower end of the outer mold frame 200 through the terminal guide groove 221.

Preferably, the terminal guide groove 221 is formed at one side surface of the molding part 220, and the end 250a of the drawn secondary coil is disposed at the terminal guide groove 221 and is guided to the lower end of the molding part 220.

As shown in fig. 5, the outer frame 210 and the molding part 220 form a stepped engagement surface. The stepped junction surface reinforces the external insulation voltage of secondary coil 250 interposed between outer bobbin 210 and molded part 220. The molding part 220 fills the gap between the secondary coils 250. The molding part 220 filling the gap between the secondary coils 250 can maintain a stable winding and can greatly improve insulation.

The end portion side of the outer frame 210 has a two-step structure having a height difference, and the joining

surfaces

210a and 220a of the outer frame 210 and the molding portion 220 form a step-shaped joining surface in insert molding. The stepped junction surface between the outer frame 210 and the molding part 220 can improve the withstand voltage by increasing the junction area.

The outer mold frame 200 has injection molded flanges 222 formed on both sides and a core joint 224 formed therebetween. The injection flange 222 is a portion formed by surrounding the upper flange 213 and the lower flange 214 of the outer frame 210 with a predetermined thickness by the molding portion 220. The core joint 224 corresponds to a height difference portion between the two side injection-molded flanges 222. The core coupling part 224 is coupled with the upper core part 310 and the lower core part 320. The width and length of the core binder 224 are designed in advance in consideration of the sizes of the upper core 310 and the lower core 320 bound to the core binder 224.

As shown in fig. 5 and 6, the outer mold frame 200 includes a support portion 225 for supporting the inner frame 100 coupled to the frame coupling hole 212. Specifically, the support portion 225 is formed at the molding portion 220. The support portion 225 supports the inner frame 100 combined with the outer frame 210. When insert-molded, the support portion 225 blocks a portion of the bobbin coupling hole 212, supporting the position where the inner bobbin 100 is coupled to the bobbin coupling hole 212.

As shown in fig. 6, the support portion 225 has a shape in which the molding portion 220 is further expanded from a portion surrounding the upper flange 213 by a predetermined thickness in the direction of the frame coupling hole 212.

The supporting portion 225 may be formed in advance in the outer frame 210, and may be formed in the molding portion 220 when insert molding. However, it is preferable that the supporting portion 225 is formed in the insert molding process and is formed at the molding portion 220. In the outer bobbin 210, the upper flange 213 and the lower flange 214 are formed in a symmetrical shape to maintain the balance of the right and left forces, because the problem of breakage of the outer bobbin 210 can be minimized during the winding of the secondary coil 250 by the outer bobbin 210.

The support portion 225 includes a support groove 226 having a recessed shape or a height difference shape on the bottom surface. The support groove 226 corresponds to a protruding rib (reference numeral 107 in fig. 3) formed on the upper surface of the upper end flange 103 of the inner frame 100. When the inner frame 100 is inserted into the frame coupling hole 212 of the outer molded frame 200, the protruding rib 107 of the inner frame 100 is closely attached to or inserted into the support groove 226 of the outer molded frame 200, so that the state in which the inner frame 100 and the outer molded frame 200 are coupled to each other can be firmly maintained.

Preferably, the outer mold frame 200 includes a support portion 225, and may be shaped without the support portion 225.

The outer molded frame 200 is provided with a placement portion 227 on the bottom surface thereof, on which an extension flange (reference numeral 105 in fig. 3) of the inner frame 100 is placed. The placement portion 227 is a portion of the bottom surface of the outer mold frame 200 formed to have a height difference from other portions. When the outside molding frame 200 is combined with the inside frame 100, the placing portion 227 can regulate the bottom surface height in a prescribed manner and allows the

core portions

310, 320 to be easily combined. The placement portion 227 is formed on the bottom surface of the outer molded frame 200 corresponding to the surface opposite to the second terminal 260.

As shown in fig. 7, an end portion 250a of the secondary coil drawn out to the outside through one side upper end of the outer mold frame 200 is formed by a terminal pin 251 and may be used as a second terminal (reference numeral 260 of fig. 8). Specifically, the end portion 250a of the secondary coil is immersed in a lead solution to be formed into a terminal pin 251 and to serve as the second terminal 260.

More specifically, as shown in fig. 6, the end portion 250a of the secondary coil drawn out to the outside is immersed in a high-temperature lead solution to form a terminal pin 251, and as shown in fig. 7, the terminal pin 251 is disposed in the terminal guide groove 221 and moved to one side lower end of the outer mold frame 200. When the end portion 250a of the secondary coil is immersed in the high-temperature lead solution, the outer skin of the end portion 250a of the secondary coil is melted by the lead and removed, and the lead adheres to the copper wire from which the outer skin is removed, and thus is easily formed as the terminal pin 251. When the end portion 250a of the secondary winding is put in a high-temperature lead solution, lead adheres to the copper wire, and the copper wire has a predetermined strength. In addition to the high-temperature lead solution, various materials may be used for the end of secondary coil 250 as long as the material melts the outer skin and adheres to the copper wire to make the copper wire have a predetermined strength and has conductivity.

If the end portion 250a of the secondary coil is formed as the terminal pin 251 to be used as the second terminal 260, a welding work for connecting the end portion of the secondary coil and the second terminal is not required, and thus a problem of poor welding and a problem of poor contact are prevented.

The terminal pins 251 may be engaged with reinforcing pins 255 for reinforcing strength. When the copper wire of secondary coil 250 is thin, it is difficult to function as a terminal due to a problem such as bending. Therefore, the terminal pin 251 is joined with the reinforcing pin 255 to reinforce the strength, and thus deformation such as bending of the terminal can be prevented. After being engaged with the terminal pins 251, the reinforcing pins 255 are disposed in the terminal guide grooves 221 together with the terminal pins 251 and move downward of the outer mold frame 200. Since the reinforcing pins 255 are disposed in the terminal guide grooves 221 and reinforce the terminal pins 251, the strength of the terminal pins 251 is more effectively reinforced. A terminal pin 251 which is moved to one side lower end of the outside forming bobbin 200 and protrudes downward is used as the second terminal 260. The reinforcing pins 255 may be applied to all the terminal pins 251 formed by immersing the end portion 250a of the secondary coil in a high-temperature lead solution, and may be applied to only a portion of a thin copper wire, as necessary.

Alternatively, the terminal pin 251 that moves to the lower end of the outer molded frame 200 on one side and protrudes downward and the reinforcing pin 255 that is disposed in the terminal guide groove 221 to reinforce the terminal pin 251 may be immersed in a high temperature lead solution to be integrated and used as the second terminal 260.

As shown in fig. 8, the outer mold frame 200 includes a tail portion 228 covering an end portion 250a of the secondary coil disposed in the terminal guide groove 221. The tail portion 228 prevents the end portion 250a of the secondary coil from being exposed to the outside from the side surface of the outer mold frame 200. The tail portion 228 may be formed by attaching epoxy resin to the terminal guide groove 221 inserted into the end portion 250a of the secondary coil formed as the terminal pin 251 or by additionally injection molding to cover the terminal guide groove 221.

Alternatively, the tail 228 may be formed by attaching an epoxy resin to the terminal guide groove 221 or by additionally molding the epoxy resin to cover the terminal guide groove 221 in a state where the terminal pin 251 and the reinforcing pin 255 are inserted into the terminal guide groove 221.

The outer molded frame 200 may be formed of a material having high heat resistance and high voltage resistance, as in the inner frame 100.

In a state where the outer mold frame 200 is coupled to the inner frame 100, the outer mold frame 200 is coupled to the

cores

310 and 320 for forming the magnetic circuit.

Referring to fig. 1, 2 and 9, the

cores

310 and 320 include an upper core 310 and a lower core 320, and are coupled to each other at upper and lower sides of the outer mold frame 200 to have a predetermined insulation gap (gap). The insulation gap can be used to adjust the inductance value.

Referring to fig. 2 and 9, the upper core 310 and the lower core 320 have an E-shape including: a section surface a; two side leg portions b vertically protruding from the cross-sectional portion a; and a center leg portion c vertically protruding between the both side leg portions b. In a state where the inner frame 100 is coupled to the outer mold frame 200, the upper core 310 and the lower core 320 are coupled to the upper and lower sides of the outer mold frame 200.

Specifically, referring to fig. 2, 5 and 9, the upper core portion 310 and the lower core portion 320 are coupled to the outer mold frame 200 such that the center leg portion c is inserted into the core coupling hole 102 of the inner frame 100 in a state where the cross-sectional portion a is closely attached to the core coupling portion 224 of the upper surface or the lower surface of the outer mold frame 200, and the center of the outer circumference of the outer mold frame 200 is surrounded in a state where the center leg portion c is coupled to the outer mold frame 200, by the both side leg portions b being closely attached to the both side core coupling portions 224 of the outer mold frame 200.

The E-shaped upper core 310 and lower core 320, the core coupling hole 102 formed in the inner frame 100, and the core coupling portion 224 formed in the outer mold frame 200 correspond to each other such that the upper core 310 and lower core 320 are closely coupled to each other without play at the outer circumference of the outer mold frame 200. The upper core 310 and the lower core 320 are fixed by Epoxy (Epoxy) welding. The upper core 310 and the lower core 320 may be welded with epoxy resin at the surface contacting the outer mold frame 200. Epoxy soldering improves water resistance, minimizes chipping when broken, and also allows easy identification of cracks.

As shown in fig. 9 and 10, in a state where the outer mold frame 200 is coupled to the inner frame 100, the thickness of the mold part 220 insert-molded in the outer frame 210, and the thickness of the outer frame 210 insulating the primary coil 150 and the secondary coil 250 may be uniformly manufactured in a range of 0.5 to 0.55, and the primary coil 150 and the secondary coil 250 may be completely shielded.

In fig. 9, p1 and p2 are primary coils, and s1, s2 and s3 are secondary coils.

The transformer according to the first embodiment can achieve moisture resistance and a large increase in insulation by completely sealing the primary coil 150 and the secondary coil 250, and thus can manufacture the outer molded bobbin 200 by minimizing the thickness of the inner bobbin 100, the thickness of the outer bobbin 210, and the thickness of the molding portion 220 without securing a minimum insulation distance.

Hereinafter, a method of manufacturing a transformer according to a first embodiment of the present invention will be described.

The transformer manufacturing method of the first embodiment includes: preparing the inner bobbin 100 around which the primary coil 150 is wound; a step of forming an outer frame 210 by a first injection molding, the outer frame 210 having a frame coupling hole 212 formed therein; a step of winding secondary coil 250 around outer bobbin 210; a step of forming an outer molded bobbin 200 by insert molding a welding material around the secondary coil 250 wound around the outer bobbin 210 so that an end 250a of the secondary coil is drawn out upward from one upper end of the secondary coil through the outer bobbin 210 and the secondary coil 250; and a step of coupling the inner bobbin 100, around which the primary coil 150 is wound, to the bobbin coupling hole 212 of the outer molding bobbin 200.

The step of preparing the inner bobbin 100 around which the primary coil is wound is as follows.

As shown in fig. 11, the inner frame 100 is prepared by injection molding so as to have a winding portion 101, an upper end flange 103, a lower end flange 104, and an extension flange 105.

Next, the terminal pin 160a is inserted into the insertion hole 106 formed in the extension flange 105 of the inner frame 100. The terminal pin 160a is inserted into the insertion hole 106 in a state where an adhesive (e.g., epoxy) is attached, and the state of insertion into the insertion hole 106 can be made firm. The terminal pin 160a inserted into the insertion hole 106 is bent downward to form the first terminal 160. Next, the primary coil 150 is wound around the winding portion 101 of the inner bobbin 100. The ends 150a of the primary coil 150 wound around the winding portion 101 are connected to the first terminals 160 by welding.

The steps for manufacturing the outer mold frame 200 are as follows.

As shown in fig. 12, the outer frame 210 having the frame coupling hole 212 is formed by first injection molding. The outer frame 210 has upper flanges 213 at upper portions of both sides and lower flanges 214 at lower portions of both sides with respect to a frame coupling hole 212 at the center, and a coil winding portion 211 is formed between the upper flanges 213 and the lower flanges 214. Further, a lead groove 215 and a fixing portion 216 are formed on one side of the upper flange 213.

Secondary coil 250 is wound around coil winding portion 211 of outer bobbin 210. The end 250a of the secondary coil wound around the coil winding portion 211 is drawn out to the upper portion of the upper flange 213 through the drawing groove 215, and then inserted into the C-shaped fixing portion 216 to be aligned.

Next, a molding material is insert-molded between the outer bobbin 210 and the secondary coil 250 to form the molding portion 220 coupled to the outer bobbin 210, so that the secondary coil 250 wound around the outer bobbin 210 is prevented from being exposed to the outside and the end of the secondary coil 250 is led out to the outside.

The molding part 220 further includes a support portion 225 blocking a portion of the bobbin coupling hole 212 to support a position where the inner bobbin 100 is coupled to the bobbin coupling hole 212. The inner frame 100 is coupled to the frame coupling hole 212 of the outer mold frame 200 at a lower portion thereof by insertion, and is caught by the support portion 225 of the mold portion 220 in a state of being inserted into the frame coupling hole 212, so as not to protrude upward.

The end portion 250a of the secondary coil is drawn out to the outside through one side upper end corner of the outer molding frame 200. The end portions 250a of the secondary coil drawn out to the outside through the one upper end corner of the outer mold frame 200 are drawn out in a row with a predetermined interval by the fixing portions 216 at the positions of the end portions 250a of the secondary coil in a row.

The end portion 250a of the secondary coil, which is drawn out to the outside at one side upper end of the outside forming bobbin 200, is immersed in a high-temperature lead solution to be formed into a terminal pin 251. The high-temperature lead solution may be a high-temperature lead solution having a temperature of about 400 to 600 ℃.

Next, the terminal pin 251 having a predetermined strength to which lead is attached is inserted into the terminal guide groove 221 by bending and moved to one side lower end of the outer mold frame 200. In this case, in order to further reinforce the strength of the terminal pin 251, a reinforcing pin 255 may be inserted into the terminal guide groove 221 to be added to the terminal pin 251. A reinforcing pin 255 is added to a portion of the end portion 250a of the secondary coil and immersed in a lead solution to remove the outer skin and form a terminal pin in which a portion of the end portion 250a of the secondary coil is integrated with the reinforcing pin 255.

The present invention forms the end 228 covering the terminal guide groove 211. Specifically, the terminal guide groove 221 is coated with an epoxy resin or additionally injection-molded to form the end 228 covering the terminal guide groove 221 so as to prevent the terminal pin 251 and the reinforcing pin 255 from being exposed to the outside from the side surface of the outer mold frame 200.

Next, the terminal pin 251 protruding to the lower portion of the outer mold frame 200 and the reinforcing pin 255 coupled to the terminal pin 251 are once immersed in a lead solution to attach lead to the terminal pin 251 and the reinforcing pin 255, thereby being used as the second terminal 260 integrally formed.

As shown in fig. 13, the transformer 10 finally manufactured has a shape in which the first terminal 160 and the second terminal 260 protrude downward on both sides of the bottom surface, respectively, and the upper core portion 310 and the lower core portion 320 are closely bonded without play on the outer periphery of the outer mold frame 200.

The operation of the present invention will be described below.

The outer molded bobbin of the present invention has a structure in which the molded portion surrounds the secondary coil, and therefore, the insulation voltage between the primary coil and the secondary coil of the inner bobbin is enhanced while maintaining a stable winding, and the insulation performance can be greatly improved.

The insulation of the primary coil and the secondary coil can prevent mutual interference between power supplies, prevent noise or impulse voltage of the primary coil, protect equipment from thunder and the like, and prevent electric shock or damage of the device caused by abnormal grounding.

In addition, the present invention reinforces insulation by complete sealing of the secondary coil, so that the thickness of the outer molded bobbin and the inner bobbin can be formed to be thin, and the outer appearance of the outer molded bobbin is formed by insert molding after the secondary coil is wound, so that the uniformity of the thickness is ensured, and the inner bobbin, the outer molded bobbin, and the core portion are closely coupled to each other so as to be fixed in position, and thus, the structural stability is high.

In the present invention, the end of the secondary coil wound around the outer bobbin and drawn out from the molding portion is immersed in a lead solution to form a terminal pin, which is used as the second terminal of the outer molding bobbin, so that the degree of connection of the boards (e.g., substrates) is improved, and disconnection due to poor soldering is prevented, thereby improving the operational reliability of the transformer.

In the present invention, when the copper wire forming the secondary coil is thin, the strength of the copper wire is reinforced by the auxiliary pin, so that the secondary coil can be used as a terminal by preventing a phenomenon such as bending.

As a result of the test, in the present invention, the insulation distance can be reduced by the completely sealed structure of the primary coil and the secondary coil, whereby the size of the transformer can be reduced by about 60% and the insulation leakage can be reduced by about 47% as compared with the conventional transformer, and the performance can be greatly improved as compared with the conventional transformer.

Further, the present invention can improve the specification of allowable drive current, improve heat generation of copper wire, ensure stable withstand voltage of winding, greatly improve insulation between winding and core, and improve the specification of insulation voltage between p1-p2 (see fig. 9).

The dimensions of the present invention were 42mm in length, 32.5mm in width and 13.7mm in thickness, and the electrical characteristics were measured. The distance between the same terminal pins is set to about 5 mm.

As a result of the measurement, it was confirmed that the inductance (inductance) of the present invention was high, the leakage was reduced by about 47%, and the voltage Drop (DCR) across the output inductor was excellent, as compared with a transformer not subjected to the same 2-type injection molding (first insert molding).

For reference, in the present invention, only the outer molded frame is insert molded, the molded portion surrounds the secondary coil, and the end portion of the secondary coil is used as the second terminal, and if necessary, the inner molded frame may be insert molded to surround the primary coil, and the end portion of the first coil may be used as the first terminal.

Second embodiment

As shown in fig. 14 and 15, a transformer 10 according to a second embodiment of the present invention includes: a molded frame 100 formed by insert molding in a state where the inner frame 110 is coupled to the outer frame 210; and

cores

310, 320 combined with the molding frame 100.

Inner bobbin 110 and outer bobbin 210 serve to physically and strongly wind primary coil 150 and secondary coil 250, respectively, and electrically insulate them. The molding bobbin 100 serves to electrically insulate the primary coil (reference numeral 150 of fig. 18) and the secondary coil (reference numeral 250 of fig. 19) from the outside.

Terminals

160, 260 are provided at the lower ends of both sides of the molding frame 100. The

terminals

160, 260 include: a first terminal 160 connected to the primary coil 150 wound around the inner bobbin 110 to serve as an input terminal; and a second terminal 260 connected to the secondary coil 250 wound around the outer bobbin 210 to serve as an output terminal. The primary coil 150 and the secondary coil 250 may use copper wires.

The

cores

310 and 320 are combined with the molded bobbin 100 to form a magnetic path electromagnetically combined with the primary coil 150 and the secondary coil 250. The

cores

310 and 320 are formed of a ferromagnetic substance that can obtain a strong magnetic flux. The ferromagnetic substance may be ferrite.

The

cores

310, 320 include an upper core 310 and a lower core 320, and the upper core 310 and the lower core 320 are combined with a predetermined insulation gap at upper and lower sides of the molding frame 100. The insulation gap can be used to adjust the inductance value.

The upper core 310 and the lower core 320 have an E-shape. The upper core 310 and the lower core 320 are combined on the upper and lower sides of the molding frame 100 in a state where the inner frame 110 is combined with the molding frame 100.

As shown in fig. 16, the inner frame 110 includes: a winding section 111 around which the primary coil 150 is wound; and a core coupling hole 112 vertically penetrating the center of the winding portion 111. The inner frame 110 includes an upper end flange 113 and a lower end flange 114, and is formed to expand in the outer diameter direction at the upper end and the lower end of the winding portion 111. The upper end flange 113 and the lower end flange 114 may have a rectangular shape in which the core combining hole 112 is formed at the center and a shape in which semi-circles are further attached at both ends in the length direction of the rectangular shape as basic shapes.

The lower end flange 114 is also formed with an extension flange 115 at one side, and a first terminal 160 is provided at the extension flange 115. The first terminal 160 has a shape in which a predetermined number of terminal pins are arranged at predetermined intervals. In the state where the terminal pin is adhered with the adhesive, the first terminal 160 is inserted and fixed into the insertion hole 116, and thus can be firmly fixed to the extension flange 115. The end of the primary coil 150 wound around the winding part 111 may be connected to the first terminal 160 fixed to the insertion hole 116 by welding.

The inner frame 110 is provided with a protruding rib 117 at the upper end flange 113. The protruding rib 117 is formed to protrude from the upper surface of the upper end flange 113, and two protruding ribs 107 may be provided along both sides with the core coupling hole 112 interposed therebetween. The protruding rib 117 serves to stably couple the inner frame 110 to the outer frame 210.

The inner frame 110 is provided with injection grooves 118 for injecting injection molding at both ends of the upper flange 113. The injection groove 118 is used to inject an injection molding for insert molding between the inner frame 110 and the outer frame 210 in a state where the inner frame 110 and the outer frame 210 are coupled.

Preferably, the inner frame 110 is formed by first injection molding, is formed of an insulating resin, and may be formed of a material having high heat resistance and high voltage resistance. For example, the inner frame 110 may use a PBT material to ensure insulation performance of 20kv/mm or more.

As shown in fig. 17, the outer frame 210 includes: a coil winding portion 211 around which the secondary coil 250 is wound; and a bobbin coupling hole 212 vertically penetrating the center of the coil winding portion 211. The frame coupling hole 212 is coupled to the inner frame 110.

The outer bobbin 210 includes an upper flange 213 and a lower flange 214, and the upper flange 213 and the lower flange 214 are formed by expanding in the outer diameter direction at the upper end and the lower end of the coil winding portion 211. Secondary coil 250 is wound around coil winding portion 211 between upper flange 213 and lower flange 214.

The portions of the coil winding portion 211 connected to the upper and

lower flanges

In the outer bobbin 210, the upper flange 213 and the lower flange 214 are formed in a symmetrical shape to maintain the balance of the right and left forces, because the problem of breakage of the outer bobbin 210 can be minimized during the winding of the secondary coil 250 by the outer bobbin 210.

The outer frame 210 includes a lead-out groove 215 and a fixing portion 216.

The lead-out grooves 215 are used to lead out grooves wound at respective ends of the secondary coil 250 of the coil winding portion 211 from an upper portion of the upper flange 213. The drawing groove 215 is formed in the upper flange 213 so as to be recessed in the rear end direction, and a plurality of the drawing grooves 215 are opened vertically.

The fixing portions 216 are arranged at predetermined intervals at respective ends of the secondary coil 250 drawn out to the upper portion of the upper flange 213. The fixing portion 216 is disposed near the entrance of the lead-out groove 215 so that the entrance of the lead-out groove 215 and the end of the lead-out groove 215 are at a position shifted from each other, and the end of the secondary coil 250 is caught by the fixing portion 216. The fixing portion 216 has a C-shaped groove that can fix the position of the end of the secondary coil 250 wound around the coil winding portion 211.

The end of the secondary coil 250 is inserted into the lead-out groove 215, is caught by the fixing portion 216, and is placed in the C-shaped groove of the fixing portion 216 to be fixed. Therefore, the drawing groove 215 is curved so that the positions of the inlet and the end are shifted, and the end of the drawing groove 215 and the fixing portion 216 are arranged on a straight line.

Like the inner bobbin 110, the outer bobbin 210 may be formed of a material having high heat resistance and high voltage resistance.

As shown in fig. 18, when the outer frame 210 coupled to the inner frame 110 is placed in a mold and insert-molded, the molded frame 100 in which the molded material is coupled between the inner frame 110 and the outer frame 210 is formed.

The molding substance is injected between the inner bobbin 110 and the outer bobbin 210 through the injection groove 118 of the inner bobbin 110 to surround the primary coil 150. The primary coil 150 is injected through the injection groove 118, and surrounds the simultaneously molded portion 220 while being cured without being exposed to the outside. Secondary coil 250 wound around coil winding portion 211 of outer bobbin 210 is surrounded by simultaneous molding portion 230 surrounding outer bobbin 210 by a predetermined thickness and is not exposed to the outside.

The end of the secondary coil 250 wound around the outer bobbin 210 is drawn out to the outside through one upper end corner of the molding bobbin 100. The end portion 250a of the secondary coil drawn out to the outside through the upper end corner of one side of the molding frame 100 is drawn out in an aligned state with a predetermined interval by the fixing portion 216 aligning the position of the end portion 250a of the secondary coil. After the secondary coil 250 is wound around the outer bobbin 210, the outer appearance of the molded bobbin 100 is formed by insert molding, so that the uniformity of the thickness can be ensured.

That is, in a state where the inner bobbin 110 is coupled to the outer bobbin 210, the molding bobbin 100 includes simultaneously molding the

portions

220 and 230 of the inner bobbin 110 and the outer bobbin 210 by injection molding so that the inner bobbin 110 and the outer bobbin 210 are integrally formed, and the end of the secondary coil 250a is drawn out to the outside while surrounding the secondary coil 250.

The mold frame 100 is provided with terminal guide grooves 221 on the side surfaces. The terminal guide groove 221 is formed in the side of the molded bobbin 100 including the corner from which the end 250a of the secondary coil is drawn. The terminal guide grooves 221 are formed in a recessed shape along the vertical direction, and a plurality of the terminal guide grooves 221 are spaced apart at predetermined intervals. The end portion 250a of the secondary coil drawn out from the upper end of the molded bobbin 100 on one side to the outside is moved toward the lower end of the molded bobbin 100 on one side by the terminal guide groove 221.

An end portion 250a of the secondary coil drawn out through one side upper end of the molded bobbin 100 may be formed as a terminal pin 251 and used as a second terminal (reference numeral 260 of fig. 21). Specifically, the end of the secondary coil 250 may be immersed into a lead solution to be formed into a terminal pin 251 and used as the second terminal 260.

The end portion 250a of the secondary coil drawn out to the outside is immersed in a high-temperature lead solution to form a terminal pin 251, and the terminal pin 251 is disposed in the terminal guide groove 221 and moved toward the lower end of the molded frame 100. When the end portion 250a of the secondary coil is immersed in the high-temperature lead solution, the outer skin of the end portion 250a of the secondary coil is melted by the lead and removed, and the lead adheres to the copper wire with the outer skin removed, so that the terminal pin 251 is easily manufactured. When the end portion 250a of the secondary coil is immersed in a high-temperature lead solution, lead adheres to the copper wire, and the copper wire has a predetermined strength. In addition to the high-temperature lead, various materials may be used for the end of the secondary coil 250 as long as the material melts the outer sheath and adheres to the copper wire to make the copper wire have a predetermined strength and has conductivity.

If the end of secondary coil 250 is formed as terminal pin 251 to be used as second terminal 260, it is not necessary to perform a welding operation for connecting the end of the secondary coil and the second terminal, and thus a problem of poor welding and a problem of poor contact are prevented.

The terminal pins 251 may be engaged with reinforcing pins 255 for reinforcing strength. The terminal pin 251 is joined with the reinforcing pin 255 to reinforce the strength, whereby deformation such as bending of the terminal can be prevented. After the terminal pins 251 are engaged, the reinforcing pins 255 are disposed in the terminal guide grooves 221 together with the terminal pins 251 and moved downward of the mold frame 100. A terminal pin 251 which is moved toward one side lower end of the molding frame 100 and protrudes downward is used as the second terminal 260. The reinforcing pins 255 can be applied to all the terminal pins 251 formed by immersing the end portion 250a of the secondary coil in high-temperature lead, and can be applied to only a part of a thin copper wire, as necessary.

Alternatively, the terminal pin 251 that moves toward the lower end of the molded frame 100 on one side and protrudes downward may be integrated with the reinforcing pin 255 that is disposed in the terminal guide groove 221 to reinforce the terminal pin 251 by being immersed in high-temperature lead, and used as the second terminal 260.

As shown in fig. 19, the molded frame 100 includes a tail portion 228 covering an end portion 250a of the secondary coil disposed in the terminal guide groove 221. The tail portion 228 may be formed by attaching epoxy resin to the terminal guide groove 221 inserted into the end portion 250a of the secondary coil formed as the terminal pin 251 or by additionally injection molding to cover the terminal guide groove 221.

Cores

310 and 320 for forming a magnetic circuit are combined with the molding frame 100.

Hereinafter, a method of manufacturing a transformer according to a second embodiment of the present invention will be described.

The transformer manufacturing method of the second embodiment includes: a step of forming an inner frame 110 and an outer frame 210 by a first injection molding, respectively, the inner frame 110 having a core portion coupling hole 112 and the outer frame 210 having a frame coupling hole 212; a step of winding the primary coil 150 around the inner bobbin 110 and bonding the first terminal 160; a step of winding secondary coil 250 around outer bobbin 210; a step of coupling the inner frame 110 to the frame coupling hole 212 of the outer frame 210; a step of forming the molded bobbin 100 by integrally forming the inner bobbin 110 and the outer bobbin 210, and insert-molding a molding material into the inner bobbin 110 and the outer bobbin 210 so as to surround the secondary coil 250 and draw an end of the secondary coil 250 to the outside; a step of immersing an end of the secondary coil 250 into a lead solution to form a terminal pin 251; a step of forming the end of the secondary coil 250 formed as the terminal pin 251 as the second terminal 260 by moving down toward the terminal guide groove 221 formed through the side of the mold frame 100; and a step of bonding the

cores

310, 320 at the molding frame 100.

As shown in fig. 20, the inner frame 110 is prepared by injection molding so as to have a shape including a winding portion 111, an upper end flange 113, a lower end flange 114, and an extension flange 115.

Next, the molded inner frame 110 is inserted into the terminal pins 160a through the insertion holes 116 formed in the extension flanges 115. The terminal pin 160a is inserted into the insertion hole 116 with an adhesive (e.g., epoxy) applied thereto, and can be firmly fixed in the state of being inserted into the insertion hole 116. The terminal pin 160a inserted into the insertion hole 116 may be bent downward to form the first terminal 160. Next, the primary coil 150 is wound around the winding portion 111 of the inner bobbin 110. The ends 150a of the primary coil 150 wound around the winding portion 111 are connected to the first terminals 160 by welding.

As shown in fig. 21, the outer bobbin 210 is prepared by injection molding so as to have a winding portion 211 and a bobbin coupling hole 212.

The outer frame 210 has upper flanges 213 at upper portions of both sides and lower flanges 214 at lower portions of both sides with respect to a frame coupling hole 212 at the center, and a coil winding portion 211 is formed between the upper flanges 213 and the lower flanges 214. Further, a lead groove 215 and a fixing portion 216 are formed on one side of the upper flange 213.

Next, the inner frame 110 is coupled to the outer frame 210.

Next, the outer frame 210 coupled to the inner frame 110 is placed in a mold, and a molded material is coupled to the inner frame 110 and the outer frame 210 by insert molding to form the

simultaneous molding portions

220 and 230.

When insert molding is performed, the simultaneously molded

parts

220 and 230 are injected between the inner bobbin 110 and the outer bobbin 210 through the injection groove 118 of the inner bobbin 110 and surround the primary coil 150, and surround the secondary coil 250 of the outer bobbin 210 to integrate the inner bobbin 110 and the outer bobbin 210.

The end portion 250a of the secondary coil is drawn out to the outside through an upper end corner of one side of the molding frame 100. The end portions 250a of the secondary coil 250, which are drawn out to the outside through the one-side upper end corner of the molding frame 100, are drawn out in an aligned state with a predetermined distance by the fixing portions 216 for aligning the positions of the end portions 250a of the secondary coil.

The end portion 250a of the secondary coil, which is drawn out to the outside at one side upper end of the molding frame 100, is immersed in a high-temperature lead solution to form a terminal pin 251. The high-temperature lead solution may be a high-temperature lead solution having a temperature of about 400 to 600 ℃.

Next, the terminal pin 251 having a predetermined strength to which lead is attached is inserted into the terminal guide groove 221 by bending and moved toward the lower end of the mold frame 100. In this case, in order to further reinforce the strength of the terminal pin 251, a reinforcing pin 255 may be inserted into the terminal guide groove 221 to be added to the terminal pin 251.

Next, the tail portions 228 are formed by attaching epoxy resin to the terminal guide grooves 221 or by additional injection molding so as to cover the terminal guide grooves 221, thereby preventing the terminal pins 251 and the reinforcing pins 255 from being exposed from the side surfaces of the mold frame 100.

Next, the terminal pin 251 protruding toward the lower portion of the mold frame 100 and the reinforcing pin 255 engaged with the terminal pin 251 are again immersed in the lead solution to attach lead to the terminal pin 251 and the reinforcing pin 255, thereby being used as the second terminal 260 by integration.

The mold frame 100 forms mold flanges 222 on both sides, with a core joint 224 formed therebetween. The molded flange 222 is a portion formed by simultaneously molding the portion 220 to surround the upper flange 213 and the lower flange 214 of the outer frame 210 by a predetermined thickness. The core coupling portions 224 correspond to the height difference portions between the side molding flanges 222, and the upper core portion 310 and the lower core portion 320 are coupled to the core coupling portions 224. The width and length of the core coupling part 224 are designed in advance in consideration of the sizes of the upper core part 310 and the lower core part 320 coupled to the core coupling part 224.

The operation of the second embodiment of the present invention will be described below.

As shown in fig. 22, the upper core 310 is combined with the lower core 320 at the upper and lower sides of the molding frame 100.

The upper core 310 and the lower core 320 having the E-shape, the core coupling hole 112 formed in the inner frame 110, and the core coupling portion 224 formed in the molding frame 100 correspond to each other, so that the upper core 310 and the lower core 320 are closely coupled to each other without play on the outer circumference of the molding frame 100. The upper core 310 and the lower core 320 are fixed by Epoxy (Epoxy) welding. The upper core 310 and the lower core 320 may be welded with epoxy resin at the surface contacting the molding frame 100. Epoxy soldering improves water resistance, minimizes chipping when broken, and also allows easy identification of cracks.

The thickness of the inner bobbin 110, the thickness of the outer bobbin 210 and the inner bobbin 110 are combined in a state where the molded bobbin 100 is combined with the

core parts

310 and 320, the thickness of the molded part 230 and the thickness of the outer bobbin 210 insulating the primary coil 150 and the secondary coil 250 are uniformly manufactured in the range of 0.5 to 0.55 while the outer bobbin 210 is insert-molded, and the primary coil 150 and the secondary coil 250 can be completely shielded.

In fig. 22, p1 and p2 are primary coils, and s1, s2 and s3 are secondary coils.

Also, as reference numeral 220 is a simultaneous molding part filling the space between the inner bobbin 110 and the outer bobbin 210 in the simultaneous molding part, and reference numeral 230 is a simultaneous molding part surrounding the outer bobbin 210.

Since the primary coil 150 and the secondary coil 250 are completely sealed to achieve moisture resistance and to greatly enhance insulation, the molded bobbin 100 can be manufactured by minimizing the thickness of the inner bobbin 110, the thickness of the outer bobbin 210, and the thickness of the molding portion 220 without securing an insulation distance.

As shown in fig. 22, in the molding frame 100, the joint surface between the outer frame 210 and the simultaneous molding part 230 is formed in a stepped shape. The stepped shape engagement of the outer bobbin 210 and the simultaneous molding portion 230 reinforces the external insulation voltage of the secondary coil 250 interposed between the outer bobbin 210 and the simultaneous molding portion 230. Further, since the molding part 230 is simultaneously filled in the gap between the secondary coils 250, a stable winding is maintained and insulation can be greatly improved. Further, the molding portion 220 maintains the stable winding of the primary coil 150 while filling the space between the inner bobbin 110 and the outer bobbin 210, and the insulation property can be greatly improved.

The outer frame 210 and the simultaneous forming part 230 form a stepped junction surface.

The second embodiment of the present invention described above is a completely sealed structure in which the primary coil of the inner bobbin and the secondary coil of the outer bobbin are respectively surrounded by insert molding, and therefore, the insulation voltage between the primary coil of the inner bobbin and the secondary coil of the outer bobbin is enhanced while maintaining a stable winding, and the insulation property can be greatly improved.

The insulation of the primary coil and the secondary coil prevents mutual interference between power supplies, prevents noise or impulse voltage on the primary coil side, protects equipment from lightning strikes, and prevents electric shock or damage of the device caused by abnormal grounding.

In the second embodiment, the terminal pin is formed by immersing the end of the secondary coil drawn out from the molded portion while being wound around the outer bobbin in a lead solution, and is used as the second terminal of the molded bobbin, so that the degree of bonding of the boards (e.g., substrates) is improved, and disconnection due to poor soldering is prevented, thereby improving the operational reliability of the transformer.

Also, in the second embodiment, in the case where the copper wire forming the secondary coil is thin, the auxiliary pin is applied to reinforce the strength of the copper wire, and therefore, a phenomenon of bending or the like can be prevented, so that the secondary coil can be used as a terminal.

In the second embodiment, the inner frame is joined to the outer frame and insert-molded to form the molded frame in which the inner frame and the outer frame are integrally formed, so that the assembly is simple, the manufacturing process is simple, and the productivity can be improved.

Third embodiment

The transformer 10 according to the third embodiment of the present invention includes the molded bobbin 100 and the

cores

310 and 320 combined with the molded bobbin 100 (see fig. 14). The transformer 10 of the third embodiment has the same outer shape as that of the transformer of the second embodiment.

The transformer 10 of the third embodiment is further formed with a molding part 120 at the inner bobbin 110, compared to the second embodiment, and the remaining structure is the same as the second embodiment. Therefore, the third embodiment will explain only the structure having a difference from the second embodiment in detail.

As shown in fig. 24 and 25, the molding frame 100 of the third embodiment includes an inner molding frame 130, an outer molding frame 210, and a simultaneous molding part 120.

The inner mold frame 130 includes an inner frame 110, a primary coil 150, and a molding portion 120.

The primary coil 150 is wound around the inner bobbin 110. The inner bobbin 110 includes a winding portion 111 around which the primary coil 150 is wound, and a core coupling hole 112 vertically penetrating the center of the winding portion 111. The inner frame 110 is provided with an extension flange 115 on the lower side.

In the extension flange 115, insertion holes 116 are formed at predetermined intervals. The first terminal 160 is inserted and fixed into the insertion hole 116. The first terminal 160 may be formed by inserting and coupling the terminal pin 160a to which the adhesive is attached into the insertion hole 116 and bending the same. The end of the primary coil 150 wound around the winding portion 111 may be connected to the first terminal 160 fixed to the insertion hole 116 by welding.

The molding portion 120 is formed by combining a molding material with the inner frame 110 by insert molding. The molding part 120 is combined with the inner bobbin 110 and the primary coil 150 to prevent the primary coil 150 wound around the inner bobbin 110 from being exposed to the outside, and to expose the first terminal 160 connected to the primary coil 150 to the outside.

As shown in fig. 25, outer bobbin 210 is wound around secondary coil 250.

The outer bobbin 210 includes a coil winding portion 211 around which the secondary coil 250 is wound, and a bobbin coupling hole 212 vertically penetrating the center of the coil winding portion 211.

The outer bobbin 210 includes an upper flange 213 and a lower flange 214, and the secondary coil 250 is wound around the coil winding portion 211 between the upper flange 213 and the lower flange 214.

The outer frame 210 has a lead-out groove 215 and a fixing portion 216 on one side. The drawing groove 215 is formed in the upper flange 213 so as to be recessed in the rear end direction, and a plurality of the drawing grooves 215 are formed vertically. The lead-out groove 215 is a groove for leading out each end of the secondary coil 250 wound around the coil winding portion 211 from the coil winding portion 211 to an upper portion of the upper flange 213.

The fixing portion 216 is disposed near the inlet of the lead-out groove 215. The fixing portions 216 are arranged at positions aligned at predetermined intervals at respective ends of the secondary coil 250 drawn out to the upper portion of the upper flange 213.

The bobbin coupling hole 212 of the outer bobbin 210 is coupled to the inner molding bobbin 130. The present invention includes the simultaneous molding part 120 simultaneously molding the outer bobbin 210 combined with the inner molding bobbin 130.

At the same time, the molding part 120 is formed by coupling a molding material to the outer bobbin 210 coupled to the inner molding bobbin 130 by insert molding, so that the secondary coil 250 wound around the outer bobbin 210 is prevented from being exposed to the outside and the end 250a of the secondary coil is led out to the outside. Meanwhile, the molding part 120 fills the space between the inner bobbin 110 and the outer bobbin 210, surrounds the secondary coil 250 coupled to the outer bobbin 210, and prevents the secondary coil 250 from being exposed to the outside.

Hereinafter, a method of manufacturing a transformer according to a third embodiment of the present invention will be described.

The transformer manufacturing method of the third embodiment includes: a step of forming an inner frame 110 having a core combining hole 112; a step of winding the primary coil 150 around the inner bobbin 110 and bonding the first terminal 160; and a step of insert-molding a molding material to form the molding portion 120 combined with the inner bobbin 110 and the primary coil 150, by using the inner bobbin 110 and the primary coil 150. The inside mold frame 130 is manufactured through the above-described process.

Also, the transformer manufacturing method of the third embodiment includes: a step of forming an outer bobbin 210 having a bobbin coupling hole 212; a step of winding secondary coil 250 around outer bobbin 210; a step of combining the inner molding frame 130 in the frame combining hole 212 of the outer frame 210; the molding material is insert-molded at the outer bobbin 210 coupled to the inner molding bobbin 130 to form the simultaneous molding part 220 coupled to the inner molding bobbin 130 and the outer bobbin 210. Through the above process, the inner molded bobbin 130 and the outer bobbin 210 are manufactured as the integrally molded bobbin 100 by the simultaneous molding part 220.

In the step of forming the simultaneous molding portion 220, the molding material is insert-molded into the inner molding bobbin 130 and the outer bobbin 210 so that the end portion of the secondary coil 250 is drawn out to the outside.

After the step of forming the simultaneous molding part 220, it includes: a step of immersing an end of the secondary coil 250 in a large lead solution to remove the outer skin and form into a terminal pin 251; a step of forming second terminals 260 by putting down the end portions of the secondary coils 250 formed as the terminal pins 251 downward by the terminal guide grooves 221 formed at the side surfaces of the mold frame 100; and a step of bonding the

cores

310, 320 at the molding frame 100.

In the step of immersing the end of the secondary coil 250 in a lead solution to remove the outer skin and form the terminal pin 251, a reinforcing pin is added to a portion of the end 250a of the secondary coil and is immersed in the lead solution to remove the outer skin and form the terminal pin 251 in which a portion of the end 250a of the secondary coil is formed integrally with the reinforcing pin.

The terminal guide groove 221 is attached with epoxy or covered with a tail 228 by additional injection molding.

In the third embodiment, the transformer 10 is manufactured by simultaneously molding the inner bobbin 110 and the outer bobbin 210 after the inner bobbin is molded to be combined, whereby the withstand voltage characteristics can be improved.

The structures of the first to third embodiments of the present invention may be applied in combination.

The present invention described above has an effect that the primary coil and the secondary coil are completely sealed, and therefore, the insulation voltage between the primary coil of the inner bobbin and the outer bobbin is enhanced by maintaining a stable winding, so that the insulation property can be greatly improved, and the withstand voltage can be improved by enhancing the strength of the molding portion.

Further, the present invention has the effect that the primary coil and the secondary coil are insulated from each other, so that mutual interference between power sources can be prevented, noise or surge voltage of the primary coil can be prevented, equipment can be protected from lightning stroke, and electric shock due to abnormal grounding or damage of the device can be prevented.

Further, the present invention can embody perfect insulation by insert molding even without impregnation, and thus can reduce the thickness of the transformer to reduce the size thereof, and can solve environmental problems, complicated process problems, and the like caused by the use of a solvent for impregnation.

The preferred embodiments of the present invention are illustrated in the drawings and described in the specification. In the following description, specific terms are used, and the terms are used only for describing the present invention, and are not used for limiting the scope of the present invention described in the meaning or the scope of the claims. Therefore, many modifications and other equivalent embodiments of the invention may be made by one of ordinary skill in the art to which this invention pertains. Therefore, the true scope of the invention is defined by the technical idea of the appended claims.

Claims

1. A transformer, characterized in that,

the method comprises the following steps:

an inner skeleton;

an outer molded frame combined with the inner frame; and

a core part combined with the outer molding frame,

comprises a primary coil wound on the inner frame,

the outer molding frame comprises:

an outer skeleton;

a secondary coil wound around the outer bobbin; and

and a molding part formed by combining a molding material with the outer frame by insert molding, so as to prevent the secondary coil wound around the outer frame from being exposed to the outside and to lead out an end of the secondary coil to the outside.

2. The transformer according to claim 1, wherein a plurality of lead-out grooves are formed in the outer bobbin, the secondary coil is inserted into the lead-out grooves, and an end of the secondary coil is led out to an upper portion of the outer bobbin.

3. A transformer according to claim 2, characterised in that the lead-out groove is curved and forms an open entrance at one side.

4. The transformer of claim 2,

a fixing part is formed at the position adjacent to the inlet in the lead-out groove,

the end of the coil drawn out along the upper part of the outer frame is locked to the fixing part and fixed.

5. The transformer according to claim 1, wherein the molded portion has a terminal guide groove formed in one side surface thereof, and an end portion of the coil drawn out is disposed in the terminal guide groove and guided to a lower end of the molded portion.

6. The transformer according to claim 5, wherein a reinforcing pin is disposed in the terminal guide groove.

7. The transformer of claim 5, including a tail portion covering said terminal guide groove.

8. The transformer of claim 1, wherein the molding part includes a support portion for supporting the inner bobbin coupled to the outer bobbin.

9. The transformer of claim 8,

a support groove or a protruding rib is formed at the support portion,

and a protruding rib or a supporting groove corresponding to the supporting groove or the protruding rib is formed in the inner frame.

10. The transformer according to claim 1, wherein the outer bobbin and the forming portion form a stepped joint surface.

11. A transformer, characterized in that,

the method comprises the following steps:

forming a framework; and

a core part combined with the molding frame,

the above-mentioned shaping skeleton includes:

an inner skeleton;

a primary coil wound around the inner bobbin;

an outer frame coupled to the inner frame;

a secondary coil wound around the outer bobbin; and

and a molding part formed by combining a molding material with the outer frame combined with the inner frame by insert molding, so as to prevent the secondary coil wound around the outer frame from being exposed to the outside and to lead out an end of the secondary coil to the outside.

12. The transformer of claim 11, wherein the molded bobbin includes a molding portion formed by joining a molding material to the inner bobbin by insert molding, so as to prevent the primary coil wound around the inner bobbin from being exposed to the outside and to expose a terminal connected to the primary coil to the outside.

13. The transformer of claim 11, wherein the simultaneous molding part fills a space between the inner bobbin and the outer bobbin.

14. The transformer of claim 13, wherein the inner bobbin is formed with an injection groove, and the molding material is injected through the injection groove such that the simultaneous molding portion fills a space between the inner bobbin and the outer bobbin.

15. A method of manufacturing a transformer, comprising:

forming an inner frame, forming a core combining hole on the inner frame;

forming an outer frame, in which a frame coupling hole is formed;

a step of winding a primary coil around the inner bobbin;

a step of winding a secondary coil around the outer bobbin; and

and forming an end of the secondary coil as a terminal.

16. The method of manufacturing a transformer according to claim 15, wherein the step of forming the end portion of the secondary coil as a terminal includes:

a part of the end of the secondary coil is immersed in a lead solution to remove the outer layer and form a terminal pin.

17. The method of manufacturing a transformer according to claim 15, wherein the step of immersing a part of the end of the secondary coil in a lead solution to remove the outer skin and form the terminal pin comprises:

and a terminal pin formed by adding a reinforcing pin to a part of the end of the secondary coil, immersing the secondary coil in a lead solution to remove the outer skin, and forming a part of the end of the secondary coil integrally with the reinforcing pin.

18. The method of manufacturing a transformer according to claim 15, wherein before the step of forming the end portion of the secondary winding as a terminal, the method comprises:

and a molding portion formed by insert molding a molding material between the outer bobbin and the secondary coil, the molding portion being coupled to the outer bobbin so as to prevent the secondary coil wound around the outer bobbin from being exposed to the outside and to expose an end portion of the secondary coil to the outside.

19. The method of manufacturing a transformer according to claim 15,

before the step of forming the end of the secondary coil as a terminal, the method further comprises:

a step of joining the inner frame to the outer frame,

after the step of joining the outer frame to the inner frame, the method includes:

and a molded part formed by insert molding a molding material between the outer bobbin and the secondary coil, the molded part being coupled to the outer bobbin and the inner bobbin so as to prevent the secondary coil wound around the outer bobbin from being exposed to the outside and to allow an end of the secondary coil to be drawn out to the outside.

20. The method of manufacturing a transformer according to claim 15,

a step of joining the inner frame to the outer frame,

before the step of combining the outer frame with the inner frame, the method comprises the following steps:

the inner bobbin and the primary coil are insert-molded to form a molded part coupled to the inner bobbin and the primary coil, so that the primary coil wound around the inner bobbin is prevented from being exposed to the outside and a terminal connected to the primary coil is exposed to the outside.