JPH09199058A - Balancing coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a ferrite core in both ends of a balancing coil bobbin from falling by the lessened number of parts. SOLUTION: A balancing coil is provided with a ferrite core 37 and balancing coils bobbins 33, the ferrite core 37 consists of a circular rotation knob 39 in which an inner screw 63 is formed in the inner circumference, an outer screw 61 to be screwed in the inner screw 63, and a through hole 59 formed in the center, and a balancing coil bobbin consists of a bobbin part 41, a closing wall 47 to close one end of the bobbin part 41, a center axis 51 which is projected out of the closing wall 47 and inserted into the through hole 59 to regulate the rotation of the ferrite core 37, and an engaging means 53 and these parts are united. The bobbin parts of two balancing coil bobbins 33 are inserted into both ends of the ferrite core 37 and the balance coil bobbins 33 are mutually connected through the engaging means 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance coil suitable for use as a deflection coil of a cathode ray tube.

[0002]

2. Description of the Related Art In a cathode-ray tube, if the three electron beams emitted from an electron gun are not concentrated at one point, the color becomes abnormal. Therefore, the electron beam is focused on the entire screen at one point to adjust the convergence. Is done. As a kind of dynamic convergence adjustment, the correction amount of the X-axis lateral misconvergence (H amplifier) is adjusted, the left-right asymmetry of the X-axis lateral misconvergence is adjusted, or the variation of the inductance L of the two horizontal deflection coils is adjusted. There is an auxiliary convergence adjustment to correct or.

A well-known balance coil is used for this auxiliary convergence adjustment. FIG. 3 shows a horizontal sectional view of a conventional balance coil. The balance coil 1 includes a hollow balance coil bobbin 3, two coils C1 and C2 wound on both sides of the balance coil bobbin 3 at appropriate intervals, and a ferrite core 7 inserted in and out of the hollow portion 5 of the balance coil bobbin 3. have. Four flange portions 9 for winding the coils C1 and C2 are integrally formed on the outer periphery of the balance coil bobbin 3 with appropriate gaps.

A hexagonal through hole 13 is formed in the central portion of the ferrite core 7 over the entire length. Further, an outer screw 15 is formed on the outer circumference of the ferrite core 7. The balance coil bobbin 3 is configured such that the inside flange portion 9 is cut so that the inserted ferrite core 7 is exposed.

A rotary knob 17 is arranged between the inner collar portions 9, and an inner screw 19 of the rotary knob 17 is screwed into an outer screw 15 of the ferrite core 7. Balance coil bobbin 3
A locking member 21 for preventing the ferrite core 7 from rotating is provided at one end of the. The locking member 21 has a central shaft 23 having a hexagonal cross section in the center, and by inserting this into the through hole 13 of the ferrite core 7, the periphery of the ferrite core 7 is regulated.

The inductance L of this balance coil 1
To adjust, the rotary knob 17 is rotated. As a result, the ferrite core 7 is moved in the central axis direction of the balance coil bobbin 3, and the insertion length in the balance coil bobbin 3 is changed, so that the magnetic field generated by the coil is changed and the inductance L is adjusted.

[0007]

However, in the above-described conventional balance coil 1, the locking member 21 for restricting the rotation of the ferrite core 7 is the balance coil bobbin 3.
Since it was provided only on one end of the
If the ferrite core 7 continues to be moved to the other end of the balance coil bobbin 3 not provided with, there is a problem that the ferrite core 7 falls off from the end of the balance coil bobbin 3. In particular, when it is difficult to visually check the balance coil 1, such a problem may occur,
If the ferrite core 7 falls off, it may come into contact with the terminals of other parts, which may cause a short circuit. Further, in order to solve such a problem, if the locking members 21 are attached to both ends of the balance coil bobbin 3, the number of parts increases, the assembly becomes complicated, and the parts cost also increases. The present invention has been made in view of the above circumstances, provides a balance coil that can prevent movement of the ferrite core at both ends of the balance coil bobbin, and can configure the structure with a small number of parts to prevent the ferrite core from falling off. The purpose is to improve the workability of assembling the balance coil and reduce the cost of parts.

[0008]

In order to achieve the above object, the structure of a balance coil according to the present invention comprises an annular rotary knob having an inner thread formed on the inner circumference thereof and an outer knob screwed onto the inner thread. A ferrite core in which a screw is formed and a through hole is formed in the center; and a bobbin portion, a closing wall that closes one end of the bobbin portion, and the ferrite core that protrudes from the closing wall and is inserted into the through hole. , A balance coil bobbin integrally formed with a central axis for restricting rotation of the locking means, and inserting the bobbin portions of the two balance coil bobbins into both ends of the ferrite core,
The balance coil bobbins are connected to each other via the locking means. Further, in the balance coil, the locking means is composed of elastic locking claws and locking holes that lock each other, and the elastic locking claws and the locking holes are arranged at symmetrical positions with the bobbin center interposed therebetween. It is preferable that Further, it is preferable that the ferrite core is formed to have a length such that at least one end of the ferrite core is in contact with the closing wall and a screwed state with the rotary knob is maintained.

In the balance coil thus constructed, when the rotary knob is rotated, the ferrite core, the rotation of which is blocked by the central shaft, is rotated by the inner screw and the outer screw to form a shaft of the bobbin portion. Will be moved in the direction. The ferrite core, which has reached the outer end of the bobbin portion by being moved, comes into contact with the closing wall, whereby movement of the ferrite core is blocked. Further, since the elastic locking claws and the locking holes that lock each other are arranged at symmetrical positions with the center of the bobbin interposed, two balance coil bobbins having the same shape can be connected to each other. Further, the entire length of the ferrite core is formed such that one end of the ferrite core is in contact with the closing wall and the screwing state with the rotary knob is maintained, so that the end of the ferrite core can be attached to any closing wall. Even in the abutting state, by rotating the rotary knob in the opposite direction, it becomes possible to move the ferrite core in a direction away from the abutting closing wall.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of a balance coil according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a balance coil according to the present invention,
FIG. 2 is a horizontal sectional view of the balance coil shown in FIG. The balance coil 31 includes two balance coil bobbins 33 having the same shape, and a ferrite core 37 that is freely inserted into and removed from a hollow portion 35 of the balance coil bobbin 33.
And a rotary knob 39 screwed to the ferrite core 37.
Consists of

The balance coil bobbin 33 has a cylindrical bobbin portion 41 and a pair of collar portions 43 provided parallel to each other at both axial ends of the bobbin portion 41. The collar portion 43 holds both side portions of the coils C1 and C2 (see FIG. 2) wound around the bobbin portion 41. In addition, each collar 4
A pair of terminals 45 are planted in the lower part of 3, and the terminal ends of the coils C1 and C2 are respectively connected to the terminals 45.

The bobbin portion 41 is closed at one end side by a closing wall 47, and is opened at the other end side as an opening portion 49. Inside the bobbin portion 41, for example, a hexagonal central shaft 51 protruding in the central axis direction of the bobbin portion 41 is provided on the closing wall 47. The central axis 51 is not limited to a hexagon as long as it has a square bar shape.

Locking means 53 is provided on the outer surface of the flange 43 on the side of the opening 49. The locking means 53 has a collar portion 43.
The elastic locking claw 55 provided on one end side of the outer surface and the collar portion 43
It comprises a locking hole 57 provided on the other end side of the outer surface. The elastic locking claw 55 has a claw part protruding from the outer surface of the flange 43 in the axial direction of the bobbin and locking the locking hole 57 at the tip. The elastic locking claws 55 and the locking holes 57 are arranged symmetrically with the center of the bobbin in between. Therefore, in the two balance coil bobbins 33, the flange portions 43 on the opening 49 side are opposed to each other, and the elastic locking claws 55 are engaged with the locking holes 57 on the other side.
It is connected integrally by being locked to.

The balance coil bobbin 33 includes a bobbin portion 4
1, collar portion 43, closing wall 47, central shaft 51, locking means 53
Are integrally molded with a resin material or the like.

On the other hand, in the center of the ferrite core 37, a hexagonal through hole 59 which coincides with the central axis 51 is formed over the entire length. An outer screw 61 is formed on the outer circumference of the ferrite core 37 over the entire length. The rotary knob 39 is formed in an annular shape and has an outer periphery subjected to knurling or the like to prevent slippage and an inner screw 6 on the inner periphery.
3 are formed. The rotary knob 39 is rotatably attached to the outer peripheral side of the ferrite core 37 by screwing the inner screw 63 into the outer screw 61.

To assemble the balance coil 31, a rotary knob 39 is screwed onto the outer periphery of the ferrite core 37, and the rotary knob 39 is arranged substantially at the center of the ferrite core 37. Next, the bobbin portions 41 of the respective balance coil bobbins 33 are inserted into both ends of the ferrite core 37 protruding from both sides of the rotary knob 39. In the ferrite core 37 inserted into the bobbin portion 41, the central shaft 51 is inserted into the through hole 59, and the rotation is restricted.

Next, the two balance coil bobbins 33 inserted into both ends of the ferrite core 37 are brought close to each other, and the elastic locking claws 55 are locked in the locking holes 57 on the other side.
As a result, the two balance coil bobbins 33 are integrally connected with the rotary knob 39 interposed therebetween, and the assembly of the balance coil 31 is completed.

In the balance coil 31 thus assembled, when the rotary knob 39 is rotated, the central shaft 51
The rotation of the ferrite core 37 is prevented by the bobbin portion 41 by the screwing structure of the inner screw 63 and the outer screw 61.
It will be moved in the axial direction of. The ferrite core 37, which has reached the outer end of the bobbin portion 41 by being moved, comes into contact with the closing wall 47,
The movement is blocked in the bobbin portion 41. That is,
The ferrite core 37 is fixed to the bobbin portion 4 by the closing wall 47.
It will be prevented from dropping from 1.

The ferrite core 37 has a closing wall 47.
It is preferable that the length is formed such that the screw engagement with the rotary knob 39 is maintained in the state of being in contact with. As a result, no matter which end wall of the ferrite core 37 is in contact with the closing wall 47, by rotating the rotary knob 39 in the opposite direction, the ferrite core 37 is again brought into contact with the closing wall 47. It is possible to move away from.

As described above, according to the balance coil 31 described above, the bobbin portion 41, the closing wall 47 for closing the end portion of the bobbin portion 41, the central shaft 51 for restricting the rotation of the ferrite core 37, and the locking means. 53 and the balance coil bobbin 33 are formed integrally with each other to form two balance coil bobbins 33.
Since one balance coil bobbin is configured by connecting the locking means 53 using the locking means 53, the ferrite core can be formed without attaching a separate locking member 21 (see FIG. 3) to the balance coil bobbin as in the conventional case. The rotation of 37 can be regulated, and furthermore, the movement of the ferrite core 37 can be regulated at both ends of the bobbin portion 41.

As a result, the ferrite core 37 can be manufactured with a small number of parts (two balance coil bobbins 33 having the same shape).
Can be prevented from falling off. In addition, since it is possible to prevent the bobbin portion 41 from falling off without attaching locking members to both ends of the bobbin portion 41, it is possible to assemble with a small number of parts, improve the workability of assembling the balance coil 31, and reduce parts cost. You can

[0022]

As described in detail above, according to the balance coil of the present invention, the closing wall for closing the end of the bobbin portion and the central shaft for restricting the rotation of the ferrite core are integrated with the balance coil bobbin. Since it is possible to connect these two balance coil bobbins using the locking means,
The rotation of the ferrite core can be regulated without using a locking member as in the prior art, and the movement of the ferrite core at both ends of the bobbin portion can be regulated. As a result, with a small number of parts, it is possible to prevent the ferrite core from falling off, improve workability in assembling the balance coil, and reduce parts cost. Also, by disposing the elastic locking claws and the locking holes that lock each other at symmetrical positions with the center of the bobbin interposed, two balance coil bobbins of the same shape can be connected to each other, and the number of parts is reduced. be able to. Further, if the entire length of the ferrite core is formed such that one end of the ferrite core is in contact with the closing wall and the screwing state with the rotary knob is maintained, the end of the ferrite core contacts any closing wall. Even if they are in contact with each other, by rotating the rotary knob in the opposite direction, it becomes possible to move the ferrite core again in the direction away from the closing wall with which it abuts, and it is possible to prevent the ferrite core from falling off from the rotary knob. it can.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a balance coil according to the present invention.

FIG. 2 is a horizontal sectional view of the balance coil shown in FIG.

FIG. 3 is a horizontal sectional view of a conventional balance coil.

[Explanation of symbols]

31 Balance coil 33 Balance coil bobbin 37 Ferrite core 39 Rotating knob 41
Bobbin part 47 Closing wall 51 Central axis 53 Locking means
55 Elastic Locking Claw 57 Locking Hole 59 Through Hole 61 External Screw 6
3 Inner screw

Claims (3)

[Claims] 1. A ring-shaped rotary knob having an inner thread formed on an inner periphery thereof, a ferrite core having an outer thread threadedly engaged with the inner thread and having a through hole formed at the center thereof, and a bobbin portion. A balance coil bobbin integrally formed with a closing wall that closes one end of the bobbin portion, a central shaft that projects from the closing wall and is inserted into the through hole to restrict rotation of the ferrite core, and locking means. The balance coil, wherein bobbin portions of the two balance coil bobbins are respectively inserted into both ends of the ferrite core, and the balance coil bobbins are connected to each other via the locking means. 2. An elastic locking claw and a locking hole for locking each other constitute the locking means, and the elastic locking claw and the locking hole are arranged at symmetrical positions with a bobbin center therebetween. The balance coil according to claim 1, wherein: 3. The ferrite core is formed to have a length such that at least one end of the ferrite core is in contact with the closing wall and is maintained in a screwed state with the rotary knob. Balance coil.