JPS605532Y2 - high voltage transformer - Google Patents

Description

[Detailed explanation of the invention] This invention combines high-voltage transformers that generate high voltage, such as flyback transformers used in television receivers, oscilloscopes, and copying machines, and multiplier voltage transformers such as rectifying elements and Kotscroft type multipliers. This relates to a resin-insulated high-voltage transformer in which the rectifier and other parts are molded and potted with the same electrically insulating resin as the magnetic core. This is to prevent deterioration of the insulation due to corona discharge in the high electric field area by preventing peeling of the electrically insulating resin from the outermost layer of the high-voltage coil or the rectifying element.

Traditionally, in television receivers and other equipment, the flyback transformer for high voltage generation and the rectifier were installed as separate parts, but recently there has been a demand for smaller, lighter, and cheaper equipment. With the increase in the number of components such as A wire ring assembly in which a high voltage wire ring 5 wound around a spool 4 is inserted and fixed on the outside of a low voltage wire ring 3 wound around a bobbin 2 with a terminal plate for attaching the wire ring 1 is attached to the magnetic core. A high voltage transformer 9 is inserted into the central legs 7, 7' of the 6, 6', and the high voltage output lead wire 10 is connected to the input terminal 12 of the multiplier voltage rectifier block 11. The lead wire 13 for taking out the high voltage output of the voltage rectifier block 11 and the take-out portions 15 and 16 of the ground lead wire 14 were housed in a case 17 provided at appropriate locations, and an electrically insulating resin 18 was injected and hardened. A high voltage generator 19 of the structure is constructed.

However, the smaller the device is, the more difficult it is to insulate the high voltage section, and the smaller the device, the more difficult it is to provide sufficient creepage distance.

Therefore, in order to prevent creeping discharge from high-potential parts to low-potential parts, the problem is solved by using electrically insulating potting resin with excellent adhesive properties for rectifying elements and rectifying devices. Many excellent potting resins naturally have excellent adhesion to magnetic cores such as ferrite magnetic cores, and since the magnetic cores are also potted with the resin, hard resins such as epoxy resins are used to prevent the magnetic permeability from decreasing. cannot be used; instead, rubber-like resins such as silicone rubber resin, unsaturated polyester resin, and urethane resin are selected.

However, since rubber-like resin has a large shrinkage during curing, if the adhesion of the magnetic core is better than that of the components of the high-voltage coil, as shown in Figure 2, the magnetic cores 6, 6' Since the electrically insulating resin 18 is pulled toward the outer legs 8, 8' of the magnetic core, the outer peripheral portion of the high voltage wire ring 5 facing the outer legs 8, 8' of the magnetic core separates from the resin. A gap 20 is created, making corona discharge more likely to occur.

When corona discharge occurs, insulation deteriorates in a short period of time, making drastic downsizing difficult.

In addition, in FIG. 2, 21 and 22 are the above-mentioned low voltage coils,
Magnet wires constituting high-voltage coils, 23 and 24 are polyester films for interlayer insulation of each coil,
25 is a gap spacer inserted into the abutting surfaces of the magnetic cores 6 and 6'.

This invention solves the drawbacks of the above-mentioned conventional example.

In other words, the surface of the magnetic core that faces the coils, rectifying elements, etc. is covered with a material that has the same or inferior adhesion of the resin to the components such as the coils and rectifying elements, and the gap caused by curing shrinkage of the potting resin is removed from the magnetic core side. This prevents the wire wheels, commutator, and potting resin from peeling off.

Embodiments of this invention will be described below with reference to the drawings in FIGS. 3 to 6.

FIG. 3 shows that the outer legs 8, 8' of the magnetic cores 6, 6' of the high voltage transformer 9 (conventional example) shown in FIG. The structure is exactly the same as that shown in Fig. 2, except that the pressure-sensitive adhesive tape 26 made of polyester or other material is wrapped around it (wider than the width of a wire ring of the same properties as the insulating film), so the same parts are shown in Fig. 2. The same symbol is attached.

With such a configuration, since curing shrinkage of the resin tends to occur inward, a gap 27 due to shrinkage is created on the surface of the magnetic core.

Next, in order to help understand this example, three models will be used to explain the phenomenon that occurs when the resin cures and shrinks.

First, as is generally known, as shown in FIG. 4, a plate 30 with a diameter D
When a circular recess 31 is carved and resin is injected into it and hardened, the resin will shrink inward and the diameter of the recess will be D1.
This creates a disc with a smaller diameter than the original one, creating a gap between it and the container.

2, as shown in Fig. 5, a circular depression 33 with a diameter D2 is carved in a plate 32 made of a material that has good adhesive properties with resin, and a circular depression 33 with a diameter D3 made of a material with poor adhesive properties with resin is inserted into the plate 32. When the resin is injected and cured, the resin is pulled outward, creating a hole larger than the diameter D3 of the cylinder 34 erected inside, and a gap is created around the cylinder 34.

Part 3 is the experiment in Part 2.The material of the plate 32 that carves the circular depression 33 and the material of the cylinder 34 that stands in it are materials that have poor adhesion to resin, and when the resin is injected and hardened, As in the case of , the resin shrinks inward, creating a gap between the outer peripheral surface of the recess 33 and the resin, and hardens while tightening the cylindrical column 34 erected therein.

In the case of the conventional configuration shown in Fig. 2, the same phenomenon as No. 2 above occurs, and a gap is created at the outer periphery of the high-voltage wire ring. Due to the same principle as the phenomenon, a gap is created on the surface of the pressure-sensitive adhesive tape 26 wound around the surface of the magnetic core.

Another embodiment of this invention is shown in FIG.

In this figure, there is a terminal 4 that can be inserted into the printed circuit board.
A high voltage wire ring 4 is divided and wound on the outside of a low voltage wire ring 43 wound around a bobbin 42 with a terminal plate having a terminal plate.
4 and the split pobbin 46 with the rectifier 45 attached thereto are inserted and fixed into the center legs 48.4 of the magnetic cores 47, 47'.
After inserting into 8', the outer leg 49.49 of the magnetic core 47, 47'
', a ball wrapped with pressure-sensitive adhesive tape 50 made of polyester or the like wider than the split pobin 46, a lead wire 51 for taking out the high voltage output, and a part 52 placed at an appropriate location are housed in a case 53. Then, a rubber-like electrical insulating resin 54 such as silicone rubber resin is injected and hardened.

At this time, a gap 55 due to curing and shrinkage of the electrically insulating resin 54
Due to the above-mentioned reason, similar to the case shown in FIG. It will adhere well to the wire ring 44.

In the embodiments described above, a case was described in which a pressure-sensitive adhesive tape made of polyester or the like was wrapped around the legs of the magnetic core.
A similar effect can be obtained by inserting a molded amount of plastic that has poor adhesion to electrical insulating resin into the leg of the magnetic core facing the wire ring. The same effect can be obtained by spraying a bad paint onto the magnetic core, and the method is not limited.

As explained above, there are cases in which a rectifier, a multiplier voltage rectifier block, and a high-place pressure output quadrangle are housed in the same case, or when a split-wound high-voltage coil is housed together with a magnetic core in a case where electrically insulating resin is used. In a transformer configured to fill
As described above, in order to ensure creeping insulation of each element, it is necessary to use an electrically insulating resin that has excellent adhesion to each element.

However, there is no convenient electrical insulating resin that adheres only to each element and not to the magnetic core. Rather, it uses a bobbin made of plastic material, wire coating, interlayer insulation film, multiple voltage Since the case of the rectifier block is more difficult to adhere to the electrically insulating resin, in the areas where these elements and the magnetic core face each other, the electrically insulating resin adheres to the magnetic core, and the gaps caused by curing shrinkage are created between each element. This caused corona discharge and creeping discharge to occur, significantly reducing the reliability of the transformer.

In this invention, by covering the magnetic core surface facing the high potential part of each element with a material that has poorer adhesion to the electrically insulating resin than the constituent members of the high potential part, the gap caused by curing shrinkage can be filled with the magnetic core. This simple method greatly improves the reliability of waist transformers by preventing corona discharge and creeping discharge from occurring on the side. By making full use of it, it is possible to downsize equipment, and it has great industrial value.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view of a conventional transformer and voltage multiplier rectifier block housed in the same case, Figure 2 is a sectional view of the transformer part of Figure 1, and Figure 3 is an embodiment of this invention. FIG. 4 and FIG. 5 are explanatory diagrams of the phenomenon of curing and shrinkage of resin, and FIG. 6 is a cross-sectional view of a transformer showing another embodiment of this invention. 1... terminal, 2... bobbin, 3...
...Low voltage wire ring, 4...Spool, 5...
...High voltage wire ring, 6...6'...Magnetic core, 7
, 7'... Central leg, 8, 8'... Outer leg, 9... High voltage transformer, 1o... High voltage output lead wire, 11 ...Multiple voltage rectifier block, 12...Input terminal, 13...High voltage output lead wire, 14...Earth lead wire, 15-- ----- Lead wire 13 take-out part, 16.
...Earth lead wire 14 extraction part, 17...
...Case, 18...Resin for electrical insulation, 1
9... High voltage generator, 20... Gap, 21... Magnet wire, 22...
・Magnet wire, 23...Polyester film, 24...Polyester film, 25
...Gap spacer, 26...Pressure sensitive adhesive tape, 27...Gap, 41...
Terminal, 42...Bobbin, 43...Low voltage wire ring, 44...High voltage wire ring, 45...
・Rectifier, 46...Divided bobbin, 47, 47'
...Magnetic core, 48,48'...Central leg,
49, 49'...Outer leg, 50...Pressure sensitive adhesive tape, 51...High voltage output lead wire,
52... Lead wire 51 extraction portion, 53...
...Case, 54...Resin for electrical insulation, 5
5... Gap.

Claims (1)

[Scope of utility model registration request] The surface of the magnetic core of the high-voltage transformer facing the high-voltage generating wire is covered with a material that is the same as or more difficult to adhere to electrically insulating resin than the constituent members of the high-voltage generating wire, and is electrically insulated. A high voltage transformer characterized in that the wire ring and the magnetic core are integrally molded with a plastic resin, or the wire ring and the magnetic core are housed in a case, and the case is filled with an insulating resin and hardened.