JPH0574631A - Flyback transformer - Google Patents

Abstract

PURPOSE:To obtain a safe flyback transformer wherein the possibility of external discharge from a high voltage part on the circuit board side of a focus pack is not present, in a flyback transformer including the focus pack CONSTITUTION:A fixing plate part 34 is installed at a part of the peripheral wall of a transformer case 9. A focus is slid, inserted into the transformer case 9, and mounted so as to be engaged with the transformer case. Casting insulative resin 32 like epoxy is buried in the part between the fixing plate part 34 and a focus case 8, and the focus pack 37 is multiple protected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer having a focus pack.

[0002]

2. Description of the Related Art FIG. 8 shows a circuit of a general flyback transformer having a focus pack. In the figure, a low-voltage coil 2 and a high-voltage coil 3 are wound around a core 1 to form a coil assembly 4, and the high-voltage coil 3 is formed.
The high voltage end side of the cathode ray tube 6 via the high voltage rectifying diode 5
Is connected to the anode 7. The coil assembly 4 is housed in the transformer case.

As shown in FIG. 9, the transformer case is provided with a recess 39 for fitting in the opening thereof, and the focus case 8 of the focus pack is mounted to the recess 39 from the outside. The circuit board 10 is housed as shown in FIG. This circuit board 10 has a focus adjustment voltage resistor 11 and a screen adjustment voltage resistor.
A resistor circuit 15 is formed of patterns of a focus adjusting voltage extracting conductor 13, a screen adjusting voltage extracting conductor 12, and a screen adjusting voltage extracting conductor 14.

On the side surface of the focus case 8, there are cylindrical walls 16 and 17.
Is projected. The external output terminals 18,
19 is fixed, and the external output terminal 18 is connected to the screen adjustment voltage output terminal 22 provided at the end of the screen adjustment voltage output conductor 14 by using a soft copper wire 20. Similarly, the external output terminal 19 is connected to the focus adjustment voltage extraction terminal 23 provided at the end of the focus adjustment voltage extraction conductor 13 by using an annealed copper wire 21.

The wall surface side of the focus case 8 facing the focus adjustment voltage resistor 11 (the back surface side of the paper surface of FIG. 7).
A focus operating shaft (not shown) is rotatably attached to the focus operating voltage resistor 11 in association with the rotation of the focus operating shaft. The voltage at the moving position is the focus adjustment voltage output conductor 13
It is introduced from the side to the external output terminal 19 through the annealed copper wire 21 and added to the cathode ray tube. In addition, the focus case 8 facing the screen adjustment voltage output conductor 14
A screen operation shaft (not shown) is rotatably attached to the side (the back side of the paper surface of FIG. 7), and a slider fixed to the screen operation shaft slides on the screen adjustment voltage resistor 12. Thus, the screen adjustment voltage at the sliding position is guided from the screen adjustment voltage extracting conductor 14 to the external output terminal 18 through the annealed copper wire 20, and is applied to the cathode ray tube from the external output terminal 18.

FIG. 4 is a sectional view showing the mounting state of the focus case 8 and the external output terminals 18 and 19. A terminal insertion hole 25 is formed in the central portion of the inner bottom surface 30 of the cylindrical walls 16 and 17 of the focus case 8. The terminal insertion hole 25 and the external output terminals 18 and 19 are fitted and attached by press fitting or the like. Has been done.

The external output terminals 18, 19 are connected to a connector 24 as shown in FIG. 5 in order to apply a voltage to the cathode ray tube 6. The connector 24 is provided with annular fitting cylinder portions 26 and 27 for fitting and mounting with the cylinder walls 16 and 17 of the focus case 8. The fitting cylinder portions 26 and 27 and the cylinder walls 16 and 17 are connected to each other. It has a structure that is fitted by fitting.

[0008]

Generally, a metallic connecting terminal 29 is provided on the side of the connector 24 as shown in FIG. 6, and the fitting cylindrical portions 26 and 27 of the connector 24 and the focus case 8 are provided.
When fitting and mounting the cylindrical walls 16 and 17 of the metal connecting terminal 29
The external output terminals 18 and 19 may come into shoulder contact with each other, and an unreasonable force may be applied to the external output terminals 18 and 19 to be fitted. The stress of the unreasonable force is applied to the focus case 8 and the focus case 8 is cracked. There was a problem such as occurrence of.

Further, since the external output terminals 18 and 19 are fitted and attached to the terminal insertion hole 25 by press fitting or the like as described above, the residual stress due to the press fitting acts on the focus case 8 and causes the focus case 8 to move. There were also problems such as cracks.

Since the conventional focus pack 37 is of a type that is fitted and attached to the transformer case 9 from the outside, the circuit board 10 of the focus pack 37 is insulated from the outside only by the focus case 8. Since the high voltage of the high-stage part of the high-voltage coil 3 of the flyback transformer is applied to the connection between the focus adjustment voltage output terminal 23 and the resistance circuit 15, if a crack occurs in the focus case 8, the high-voltage connection will be removed from this connection. There is a risk of discharge to the outside through cracks, which is a safety issue.

The present invention is intended to solve the above-mentioned conventional problems, and an object thereof is a flyback transformer with a built-in focus pack, in which there is no danger of discharge from the high voltage portion on the circuit board side of the focus pack to the outside. To provide a good flyback transformer.

[0012]

In order to achieve the above object, the present invention is configured as follows. That is, in the flyback transformer of the present invention, in the flyback transformer in which the focus pack is attached to the transformer case, the operation shaft for adjusting the output voltage is projected to the outside from the mounting plate portion provided on a part of the peripheral wall of the transformer case. The focus pack is housed in the transformer case, and the casting insulating resin injected into the transformer case is filled between the mounting plate portion and the focus pack.

[0013]

A high voltage is applied to the high voltage portion of the focus pack circuit board from the high voltage coil side. This high-voltage part is multiply protected by the mounting plate part of the transformer case, the case of the focus pack, and the cast insulating resin filled between them, so that the withstand voltage is dramatically increased, and the high-voltage part is exposed to the outside. The fear of discharge is reliably prevented.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals will be given to the same names as those in the conventional example, and detailed description thereof will be omitted. This embodiment relates to a flyback transformer equipped with a focus pack as in the conventional example. The feature of this embodiment is that the focus pack is housed in a transformer case and a mounting plate provided in the transformer case. This structure has a structure in which a high-pressure portion of the focus pack is multi-protected by filling a cast insulating resin between the portion and the focus pack, and other configurations are the same as those of the conventional example. FIG. 1 shows an exploded perspective view of the fitting and mounting of a focus case and a transformer case having the above-mentioned unique multiple protection structure. FIG. 2 is a perspective view showing the fitted state of the transformer case and the focus pack in the embodiment. 3A is a sectional view taken along the line AA of FIG. 2, and FIG. 3B is a sectional view taken along the line BB of FIG. In these figures, the focus pack 37 is the fitting claw.
46, the coupling member 28 is engaged and attached to the connecting member 28, the bobbin 42 of the transformer coil is also engaged and attached using a not-shown claw, and further, the anode holder 41 holding the anode lead is also connected to the connecting member 28. The focus pack 37, the transformer coil, and the anode holder 41 are integrated via a connecting member 28. On the side of the voltage adjusting operation shafts 35, 45 of the focus pack 37, there is formed a sliding portion 43 which surrounds the operation shafts 35, 45 and has a strip plate projecting in an inverted U shape.

On the upper flat end surface 48 of the transformer case 9, an outer cylinder wall 51 fitted to the tip side of the anode holder 41 mounted on the focus pack 37, and an outer cylinder fitted to the cylinder walls 16 and 17 of the focus case 8. Walls 49 and 50 are projected. When the cylindrical walls 16 and 17 are fitted into the external cylindrical walls 49 and 50, the cylindrical walls 16 and 17 are structured to project upward from the upper end surfaces of the external cylindrical walls 49 and 50. Also, transformer case 9
A flat plate-shaped mounting plate portion 34 is provided on the front surface of the peripheral wall 33, and a vertically long opening portion 54 is provided in the mounting plate portion 34, and a side wall 55 is provided at the opening end edge of the opening portion 54. The side wall 55 is projected to the sliding portion of the focus pack 37.
It is formed as a slide guide 44 for fitting with 43. The focus pack 37 is attached to the slide guide 44.
The opening 54 is closed by fitting and mounting the sliding portion 43, and the focus pack 37 is housed inside the transformer case 9. At this time, a gap 36 is formed between the mounting plate portion 34 of the transformer case 9 and the focus case 8 as shown in FIG. On the other hand, the slide guide 44 and the sliding portion 43 allow the opening 54 of the transformer case 9 to
Is closed, so if a casting insulating resin 32 such as epoxy is injected from the bottom side of the fitted transformer case 9,
The casting insulating resin 32 is filled into the gap 36 without leaking to the outside, and the casting insulating resin 32 is also filled in the inside 52 of the focus case 8.

According to this embodiment, since the sliding portion 43 and the slide guide 44 are fitted by the slide insertion method, the transformer case 9 and the focus case 8 can be easily fitted and mounted. The work efficiency of the assembly work can be improved.

Further, in the gap 36 between the mounting plate portion 34 provided on the transformer case 9 and the focus case 8, a casting insulating resin is used.
32 is filled and the focus case 8 is multi-protected and reinforced, so that when the external output terminals 18 and 19 are press-fitted into the terminal insertion holes 25 and residual stress occurs in the focus case 8, or when the external output terminals 18 and 19 are generated. When connecting the connector 24 to the connector 24, the metallic connection terminal 29 provided on the connector 24 and the external output terminal 18,
Even if 19 contacts the shoulder and an unreasonable force is applied, the multiple protection is reinforced to overcome the external force and overcome, and the focus case 8 can be surely prevented from cracking.

Further, since the dielectric breakdown voltage of the focus pack 37 is dramatically increased by this multiple protection, even if a high voltage is applied from the high voltage coil 3 to the high voltage portion of the focus pack 37 on the circuit board 10 side, the circuit of the focus pack 37 is increased. The risk of discharge from the high voltage portion on the substrate 10 side to the outside is reliably prevented.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, although the epoxy resin is used as the casting insulating resin 32 in the above-described embodiment, the casting insulating resin 32 is not limited to this, and any insulating material that can be cast may be used.

[0020]

According to the present invention, the focus pack is housed in the transformer case, and a casting insulating resin is injected and cured between the mounting plate portion provided on a part of the peripheral wall of the transformer case and the focus case to form the focus pack. I protected multiple layers,
The withstand voltage of the focus pack is dramatically increased, and discharge from the high voltage part of the focus pack to the outside can be reliably prevented.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a transformer case and a focus pack of a flyback transformer according to this embodiment.

FIG. 2 is a perspective view showing a fitted state of the transformer case and the focus pack of the embodiment.

FIG. 3 is a sectional view of each part of FIG.

FIG. 4 is a cross-sectional view showing a mounting state of a general focus case and an external output terminal of a flyback transformer.

FIG. 5 is an exploded perspective view showing a mounting operation of the external output terminal of the focus case and the connector.

FIG. 6 is a sectional view showing a general mounting state of an external output terminal of a focus case and a connector.

FIG. 7 is a schematic explanatory view of a general focus pack mounted on a flyback transformer.

FIG. 8 is a circuit diagram of a general flyback transformer including a focus pack.

FIG. 9 is a cross-sectional view of essential parts showing a fitted state of a conventional transformer case and a focus case.

[Explanation of symbols]

 8 Focus case 9 Transformer case 18 External output terminal 32 Cast insulating resin 34 Mounting plate 37 Focus pack

Claims (1)

[Claims] 1. In a flyback transformer in which a focus pack is attached to a transformer case, the focus pack is provided by projecting an operation shaft for adjusting an output voltage outside from a mounting plate portion provided on a part of a peripheral wall of the transformer case. A flyback transformer housed in a transformer case, wherein a casting insulating resin injected into the transformer case is filled between the mounting plate portion and the focus pack.