JP2000200726A - Fly-back transformer and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fly-back transformer which has a couple of upper and lower cores adhered and fixed without requiring any temporary fixing jig for temporary fixation. SOLUTION: This fly-back transformer eliminates the need for a process for caking an adhesive when the couple of upper and lower cores 13 and 14 are fixed with the adhesive 16 by pressing the bottom-side part 14 of a core in between clamp pieces 34 of a case 10 and holding it and caking the adhesive 16 dripped previously on the joint surface between the cores 13 and 14 by heating carried out when insulating epoxy resin 24 which is injected into the case 10 thereafter is hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flyback transformer and a method of manufacturing the same, and more particularly to a flyback transformer suitable for generating a high voltage applied to an anode of a cathode ray tube and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a display device using a cathode ray tube such as a color television receiver or a display monitor of a computer, a high voltage is applied to an anode portion of the cathode ray tube. Such a high voltage is generated by a flyback transformer.

In a flyback transformer, a primary coil and a secondary coil are wound around a core made of ferrite or the like, inserted into a case, and an insulating resin is injected into the case and cured. Insulation is ensured. Here, the core is divided into a portion on the opening side and a portion on the bottom side with respect to the case, and these are inserted into the case from the opening side and the bottom side with respect to the case, and are assembled. .

In the case of using a two-piece core as described above, it is necessary to fix the core in a state where the cores are joined to each other. Therefore, conventionally, fixing has been performed using a band or a spring.

In this case, the portion of the core on the opening side is attached to the case from the opening side, the portion of the core on the bottom side is attached from the bottom side, and the end faces thereof abut each other. In such a state, the two are mechanically connected and fixed by mechanical fixing means such as a band or a spring. Then, in such a state, the insulating resin is injected and filled into the case with the upper part of the case facing upward.

[0006]

According to a method of mechanically fixing a pair of upper and lower cores of a flyback transformer using a band or a spring, a band or a spring constituting such fixing means is required. This increases the number of parts. In addition, the number of manufacturing steps for mounting and fixing such a band or spring increases, leading to an increase in cost.

Therefore, it is considered to fix the upper and lower cores with an adhesive. However, even in the case of bonding with an adhesive, some temporary fixing is required until the adhesive is solidified because the upper and lower cores are not connected to each other. Therefore, even in the case of bonding with an adhesive, a pair of cores is fixed in advance using a jig such as a fixing band, the adhesive is solidified in such a state, and then the fixing jig is removed. Was like that.

Although the fixing jig can be used repeatedly, the use of an adhesive requires the mounting of the fixing jig and the removal of the jig, which further increases the number of steps. Was supposed to. As a result, there has been a problem that fixing with an adhesive does not necessarily lead to a reduction in the cost of the flyback transformer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and is particularly useful when a pair of cores respectively attached to the case from the opening side and the bottom side are fixed with an adhesive. An object of the present invention is to provide a flyback transformer and a method for manufacturing the flyback transformer, which do not require temporary fixing by a tool.

[0010]

According to the present invention, an opening portion and a bottom portion of a core are inserted into the case from the opening side and the bottom side of the case, respectively, and the outer peripheral portion of the core assembled by these components is inserted. Wherein a primary coil and a secondary coil are wound in the case, and the primary coil and the secondary coil are sealed by an insulating resin injected into the case. The bottom portion of the core is locked by the locking portion of the case, and the bottom portion and the opening portion of the core are adhered and fixed to each other by an adhesive. It relates to a flyback transformer.

Here, a pair of sandwiching pieces may be protrudingly provided on the bottom side of the case, and a portion on the bottom side of the core may be sandwiched and held between the sandwiching pieces. Further, the core may be adhered in a state where a spacer is interposed between end surfaces of the core on the bottom side and the opening side.

[0012] The invention relating to the manufacturing method comprises a primary coil and a secondary coil.
Along with disposing the next coil in the case, the opening side portion and the bottom side portion of the core with respect to the case are inserted from the opening side and the bottom side of the case, respectively, and from the opening side into the case. In a method of manufacturing a flyback transformer in which an insulating resin is injected and solidified, a bottom portion of the core is inserted and locked to the case, and an adhesive is attached to an end surface of the bottom portion of the core. While dropping, and inserting the portion of the opening side of the core into the case,
The present invention relates to a method for manufacturing a flyback transformer, which comprises injecting an insulating resin into the case and simultaneously curing the insulating resin and solidifying the adhesive.

[0013] Here, in a state where the bottom side of the core is attached to the case, the case is mounted on a jig with the opening side thereof facing upward, and the adhesive is dropped and insertion of the opening side portion of the core is performed. And injection of an insulating resin may be performed. Prior to or after the adhesive is dropped, a spacer may be placed on the end surface of the bottom side portion of the core. Further, the curing of the insulating resin and the solidification of the adhesive may be performed in a heated atmosphere. Further, the plurality of cases may be placed on a jig and introduced into a heating furnace to cure the insulating resin and solidify the adhesive.

In a preferred embodiment of the present invention, a flyback transformer for supplying a high voltage to an anode portion of a cathode ray tube, particularly when the upper and lower cores of the flyback transformer are mechanically fixed with an adhesive, The core at the bottom, that is, the bottom side of the case is held in the case of the flyback transformer, and the adhesive is solidified by heating at the time of injecting and hardening an insulating resin such as an insulating epoxy resin. It is notable that the temporary fixation is unnecessary.

As a result of intensive studies conducted by the present inventor, when the upper and lower cores are mechanically fixed with an adhesive,
By holding the upper core in the flyback transformer case and solidifying the adhesive by heating used in the process of injecting and hardening the insulating resin such as epoxy resin, the core is not temporarily fixed when bonding the core. It has been found that bonding can be performed, and this has led to the present invention.

According to the above aspect, when the upper and lower cores are mechanically fixed with an adhesive, the lower core is held by the flyback transformer case, and the insulating resin is provided inside the case. In this case, the adhesive is solidified by heating at the time of pouring and curing, thereby eliminating the need for temporary fixing when bonding the core. Therefore, it is not necessary to temporarily fix the core with the fixing jig. Therefore, in such a flyback transformer, its effect is greatly exerted, and it is possible to supply a stable quality flyback transformer for a cathode ray tube at a low cost.

[0017]

1 and 2 show a flyback transformer according to an embodiment of the present invention. The flyback transformer is a case 1 made of a synthetic resin.
0 is provided. The case 10 has a substantially cup-like shape, the upper part of which is constituted by an opening 11, and the bottom part 12 is closed. Then, a portion 13 on the opening side of the core is mounted in the case 10 from above, and the case 10
The bottom portion 14 of the core is mounted from the bottom side of the core. Each of these cores 13 and 14 has a U-shape.

The opening 13 of the core and the bottom 14 of the core, which are attached to the case 10 from above and below, are adhered to each other by an adhesive 16 via a spacer 15 at their joint surfaces. Spacer 1
5 is mounted to prevent magnetic saturation.

In the outer periphery of the cores 13 and 14 and in the case 10, a primary coil 21 is provided via a bobbin 20.
Is wound on the outer peripheral side of the primary coil 21.
2 are wound. Note that a cylindrical separator 23 is interposed between the primary coil 21 and the secondary coil 22. In order to insulate these coils 21 and 22, the insulating resin 2 is inserted into the case 10 through the upper opening 11.
4 has been injected and cured. Note that a lead pin 25 protrudes from the upper opening 11 of the case 10.

A cover plate 29 also serving as a mounting plate is mounted so as to close the opening on the side surface of the case 10.
Adjustment knobs 30 are attached to such a cover plate 29 vertically. Further, the case 10 is provided with a cylindrical protrusion 31 so as to protrude downward. The high-voltage lead wire is drawn out of the case 10 by the cylindrical protrusion 31.

Next, the assembly of such a flyback transformer will be described. First, a bobbin 2 in which a primary coil 21 and a secondary coil 22 are wound in a case 10 respectively.
Insert 0. Then, as shown in FIG. 3, the case 10 is turned upside down, and the bottom portion 14 of the core is inserted into the case 10 using the circular opening 17 formed in the bottom 12 of the case 10. 2 on the bottom 12 side of the case 10.
As shown in FIG. 5, a pair of sandwiching pieces 34 are provided in advance.
The distance between the holding pieces 34 is slightly smaller than the width of the portion 14 on the bottom side of the core.
On the other hand, the bottom portion 14 of the core inserted from the bottom is sandwiched by the pair of sandwiching pieces 34, whereby the bottom portion 14 of the core is fixed to the case 10. Will be done.

In this way, the bottom portion 14 of the core is incorporated into the case 10 and the bottom portion 1
The case 10 is turned upside down in a state where the case 4 is sandwiched by the pair of sandwiching pieces 34, and such a case 10 is mounted on a jig 40 shown in FIGS. 7 and 8 as shown in FIG. . At this time, the cylindrical projection 31 is inserted into the cylindrical support portion 42 of the jig 40 and the U-shaped support base 44 of the jig 40 is inserted.
A portion on the bottom 12 side of the case 10 is supported by a support piece 45 protruding inward. Thereby, as shown in FIG. 4, the case 10 is stably supported on the jig 40.

After the case 10 is supported on the jig 40, the spacer 15 is placed on the end face of the bottom portion 14 of the core in such a state, and the adhesive 16 is dropped. It is preferable that the spacer 15 is similarly placed on the end face of the portion 14 on the bottom side of the core located inside the case 10 and the adhesive 16 is dropped.

After the adhesive 16 is dropped, the opening 13 of the core is attached from above the case 10 as shown in FIG. 5, and the opening 13 of the core is inserted into the case 10. Then, the end face of the portion 13 on the opening side of the core comes into contact with the end face of the portion 14 on the bottom side of the core via the spacer 15 and is bonded to each other by the adhesive 16.

Thereafter, an epoxy resin for insulation is injected into the case 10 through the upper opening 11. When the epoxy resin is injected, the case 10 is introduced into a heating furnace while being placed on the jig 40, and the epoxy resin injected into the case 10 is cured by heating and the adhesive 16 is solidified. .

As shown in FIGS. 7 and 8, a jig used for bonding the cores 13 and 14 and injecting the insulating resin into the case 10 includes six cases 10 on a base 41. As shown in FIG. It can be placed. Therefore, the filling and curing of the insulating resin of the six flyback transformers and the solidification of the adhesive 16 can be performed at one time.

As described above, the present embodiment is provided with the pair of sandwiching pieces 34 for fixing the core 14 on the bottom side to the case 10. The fixing of the core 14 by the holding pieces 34 is performed by press-fitting the core 14 between the holding pieces 34. Instead of press fitting, the core 14 may be fixed by a locking structure. In other words, any method may be used as long as the core has sufficient strength to support its own weight.

Since the core 14 is held by the holding pieces 34, even when the case 10 is turned upside down from the position shown in FIG. 3 to the position shown in FIG. To maintain. Therefore, in such a state, the case 10 is placed on the jig 40, and the adhesive 16 is dropped on the adhesive fixing portion of the core 14.

Thereafter, the core 13 on the opposite side is mounted in the case 10 by its own weight as shown in FIG. And case 10
In the step of heating the insulating resin injected into the inside, by solidifying the adhesive 16, a pair of cores 13,
It is not necessary to temporarily fix 14.

That is, in this embodiment, the upper and lower cores 1
When the mechanical fixation of 3 and 14 is performed using the adhesive 16, the lower core 14 is held by the case 10,
By solidifying the adhesive 16 by heating when the insulating epoxy resin 24 is injected and cured, the core 1 is hardened.
This eliminates the need for temporary fixing during bonding of 3 and 14.
Therefore, it is not necessary to temporarily fix the cores 13 and 14 by the temporary fixing jig. Therefore, such a structure eliminates the need for mechanical fixing means. In addition, there is no need to attach and detach the temporary fixing jig, and the number of steps is reduced, which contributes to the cost reduction of the flyback transformer.

[0031]

According to one aspect of the present invention, an opening portion and a bottom portion of the core are inserted into the case from the opening side and the bottom side of the case, respectively, and the outer peripheral portion of the core assembled by these is inserted. In a flyback transformer in which a primary coil and a secondary coil are wound in a case, and the primary coil and the secondary coil are sealed by an insulating resin injected into the case, the case is locked. The portion locks the bottom portion of the core, and the bottom portion and the opening portion of the core are adhered and fixed to each other by an adhesive.

Therefore, according to such a flyback transformer, it is possible to bond and fix the core by using an adhesive without using a band or a spring for fixing the bottom portion and the opening portion of the core. become. Moreover, since the case side portion of the core is locked by the locking portion of the case, a jig for temporarily fixing the bottom side portion and the opening side portion of the core to each other in a manufacturing process. Is no longer necessary.

The main invention relating to the manufacturing method is to dispose a primary coil and a secondary coil in a case, and to connect a core opening side portion and a bottom side portion to the case opening side with respect to the case, respectively. In a method of manufacturing a flyback transformer, which is inserted from the bottom side and is solidified by injecting the insulating resin into the case from the opening side, the bottom portion of the core is inserted and locked to the case, Adhesive is dripped onto the end face of the bottom side part of the core, the opening side part of the core is inserted into the case, the insulating resin is injected into the case, and the curing of the insulating resin and the solidification of the adhesive are performed. This is done at the same time.

Therefore, according to such a manufacturing method, the opening side portion and the bottom side portion of the core can be securely bonded to each other with an adhesive, and can be joined.
Such a step of solidifying the adhesive can be performed simultaneously with the curing of the insulating resin, thereby shortening the steps.

[Brief description of the drawings]

FIG. 1 is a side view of a flyback transformer.

FIG. 2 is a front view of the flyback transformer.

FIG. 3 is a side view showing an operation of inserting a bottom portion of the core into a case.

FIG. 4 is a side view of a case attached to a jig.

FIG. 5 is a side view of the case showing attachment of a portion on the opening side of the core.

FIG. 6 is a side view of the case where the upper and lower cores are bonded to each other.

FIG. 7 is a plan view of a jig.

FIG. 8 is an enlarged perspective view of a main part of the jig.

[Explanation of symbols]

10 ‥‥ case, 11 ‥‥ top opening, 12 ‥‥ bottom, 1
3 ‥‥ core opening side, 14 ‥‥ core bottom side, 15 ‥‥ spacer, 16 ‥‥ adhesive, 17 ‥‥ circular opening, 20 ‥‥ bobbin, 21 ‥‥ primary coil, 22 ‥
{Secondary coil, 23} Separator, 24} Insulating resin, 25} Lead pin, 29} Lid plate (mounting plate),
30 ° adjusting knob, 31 ° cylindrical protrusion, 34 ° clamping piece, 40 ° jig, 41 ° base, 42 ° cylindrical support, 43 ° step, 44 ° Character-shaped support, 45 °
Support strip

Claims (8)

[Claims] 1. An opening portion and a bottom portion of a core are inserted into a case from an opening side and a bottom portion of the case, respectively, and an outer peripheral portion of a core assembled by these is inserted into the case. In a flyback transformer in which a primary coil and a secondary coil are enclosed by an insulating resin injected into the case, the primary coil and the secondary coil are wound around the secondary coil and the secondary coil. A flyback transformer wherein a bottom portion of the core is locked, and a bottom portion and an opening portion of the core are adhered and fixed to each other by an adhesive. 2. The core according to claim 1, wherein a pair of holding pieces are protruded from a bottom side of the case, and a portion of the core on the bottom side is held between the holding pieces. Flyback transformer. 3. The flyback transformer according to claim 1, wherein a spacer is interposed between end surfaces of the core on the bottom side and the opening side facing each other with a spacer interposed therebetween. . 4. A primary coil and a secondary coil are arranged in a case, and an opening side and a bottom side of a core with respect to the case are respectively separated from an opening side and a bottom side of the case. A method for manufacturing a flyback transformer, wherein an insulating resin is injected into the case from an opening side and solidified, and a bottom portion of the core is inserted and locked to the case. An adhesive is dropped on the end surface of the bottom side portion, the opening portion of the core is inserted into the case, an insulating resin is injected into the case, and the insulating resin is cured and the bonding is performed. A method for manufacturing a flyback transformer, comprising simultaneously solidifying an agent. 5. A case in which the bottom side of the core is attached to the case and the case is mounted on a jig with the opening side thereof facing upward, and the adhesive is dropped and the opening of the core side is inserted. 5. The method according to claim 4, wherein the step of injecting an insulating resin is performed. 6. The flyback transformer according to claim 4, wherein a spacer is mounted on an end face of a bottom side portion of the core before or after the adhesive is dropped. Method. 7. The method according to claim 5, wherein the curing of the insulating resin and the solidification of the adhesive are performed in a heated atmosphere. 8. The apparatus according to claim 7, wherein the plurality of cases are placed on a jig and the case is introduced into a heating furnace to cure the insulating resin and solidify the adhesive. Manufacturing method of flyback transformer.