JPH0546902A - Cylindrical rotary transformer - Google Patents

Abstract

PURPOSE:To prevent damage to a winding in the mounting thereof in a groove which is formed in the circumferential direction of an inner circumference of a cylindrical ferrite core. CONSTITUTION:A chamfered part 4 (part cut angularly) is provided so as to cut a core angle part of a part where a bottom surface 2a of a groove 2 for a winding crosses a side 3a of a slit groove 3 for pulling a terminal wire. This allows the prevention of a damage to a wire at a part where a terminal wire is pulled out from the groove for the terminal wire thereby producing a highly reliable and inexpensive cylindrical rotary transformer by a method of mounting the winding directly into a specified groove using a winding holding means expandable radially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical rotary transformer used for VTR (video tape recorder), DAT (digital audio tape recorder) and the like.

[0002]

2. Description of the Related Art Conventionally, as a method for mounting a winding in a groove formed in a circumferential direction of an inner peripheral surface of a cylindrical ferrite core, as disclosed in Japanese Patent Application Laid-Open No. 2-58311, an inner peripheral surface is disclosed. With respect to the cylindrical ferrite core provided with the groove formed in the circumferential direction and the slit groove formed in the axial direction, the wire is wound around the outer peripheral surface of the winding holding means that can be opened and closed radially,
A manufacturing method is proposed in which the winding holding means is inserted into the core, then radially expanded to plastically deform the winding, and the winding is directly mounted in the groove of the inner peripheral surface of the cylindrical ferrite core. Has been done.

FIG. 6 is a cutaway perspective view showing such a conventional cylindrical ferrite core, in which a winding is attached to the inner peripheral surface of the cylindrical ferrite core generally indicated by reference numeral 1 in FIG. A plurality of winding grooves 2 formed in the circumferential direction and a plurality of terminal wire drawing slit grooves 3 formed in the axial direction for drawing the terminal wire of each winding are provided.
On the other hand, for example, in the winding guide 10 on the outer peripheral surface of the winding holding means 9 as shown in FIG. After being inserted into the winding holding means 9, the winding holding means 9 is expanded in the radial direction to plastically deform the winding 5, whereby the winding 5 is mounted in the winding groove 2 and The terminal wires 6 and 7 at both ends of the terminal 5 are located in the slit groove 3 for drawing the terminal wire.

[0004]

The prior art according to the prior application, in which the winding is mounted in the groove formed in the circumferential direction of the inner peripheral surface of the cylindrical ferrite core by the above-mentioned method, requires a small number of steps and a short time. Assembleable manufacturing method can be realized. By the way, when the wire is wound in the guide groove formed on the outer peripheral surface of the winding holding means 9 which can be opened and closed radially, one end wire 7 of the winding 5 is aligned with the winding direction as shown in FIG. Since it is pulled out in the orthogonal direction, the one end wire 7 rides on the circumferential coil portion of the winding 5, and this riding portion
A state in which the wire diameter of the used wire material protrudes outward from the outer diameter of the circumferential coil portion (projection portion 8 in FIG. 5). Therefore, in the prior art, the winding holding means 9 is inserted into the cylindrical ferrite core 1 and then radially expanded to expand the winding 5
When the winding 5 is plastically deformed and the winding 5 is directly attached to the winding groove 2 on the inner peripheral surface of the cylindrical ferrite core 1, the bottom surface 2a of the winding groove 2 and the terminal wire drawing slit provided in the circumferential direction. Core corner portion C formed by intersecting the side surface 3a of the groove 3 and being substantially orthogonal
In (see FIG. 6), due to the dragging of the terminal wire 7 (at the base end side bent portion of the terminal wire 7) during plastic deformation of the winding,
There was a problem that the root side of the protruding portion 8 of the terminal wire 7 abuts on the core corner portion C and damages the winding.

The present invention has been made in view of the above points,
The purpose is to provide a cylindrical rotary transformer that can prevent damage to the winding as much as possible when mounting the winding in the groove formed in the circumferential direction of the inner peripheral surface of the cylindrical ferrite core. To do.

[0006]

In order to achieve the above object, the cylindrical rotary transformer of the present invention is provided with a bottom surface of a circumferential groove on the inner peripheral surface of a cylindrical ferrite core and the groove. In order to guide the end wire of the winding to the end face side of this cylindrical ferrite core, the side faces of the slit grooves formed deeper than the circumferential groove in the axial direction of the inner peripheral surface, the plurality of intersecting slit grooves are formed. Of the core corners, at least the core corners from which the terminal wire of the winding is actually drawn out are formed as corner removal portions.

[0007]

The function of the cylindrical rotary transformer configured as described above is as follows:
The bottom surface of the winding groove provided in the circumferential direction of the inner circumferential surface and the side surface of the terminal wire drawing slit groove provided in the axial direction of the inner circumferential surface intersect at substantially orthogonal core corners. Since there are corner removal parts such as chamfers, after inserting the winding holding means of the winding device into the core, expand this in the radial direction to form the winding around the inner circumference of the cylindrical ferrite core. When installing in the groove of the surface, it is possible to prevent damage to the terminal wire of the winding,
It is possible to improve reliability.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cutaway perspective view of a core of a cylindrical rotary transformer according to a first embodiment of the present invention. In FIG. 1, 1 is a cylindrical ferrite core and 2 is a circumference of an inner peripheral surface of the cylindrical ferrite core 1. The plurality of winding grooves 3 formed in the axial direction are the plurality of terminal wire drawing slit grooves formed in the axial direction of the inner peripheral surface of the cylindrical ferrite core 1. In the figure, the terminal wire drawing slit grooves are shown. Although only one is shown for 3,
Actually, a plurality of lines are formed. Further, the depth of the slit groove 3 for drawing out the terminal wire is set to be deeper than the depth of the winding groove 2 by a predetermined amount. Reference numeral 4 denotes a chamfered portion (corner-removed portion) 4 provided at a corner portion of the core formed by the bottom surface 2a of the winding groove 2 and the side surface 3a of the terminal wire drawing slit groove 3 intersecting each other. The chamfered portion 4 is formed only at the corner portion of the core on the side where the terminal wire located on the outer diameter side of the circumferential coil portion of the winding wire is led out.

The above-mentioned FIG. 5 shows a cylindrical ferrite core 1
3 shows a state in which the winding holding means in the device for mounting the winding in the inner peripheral groove of the winding is wound. As shown in the figure, the winding 5 wound in the winding guide 10 formed on the outer peripheral surface of the winding holding means 9 includes one of the two terminal wires 6 and 7. Rides on the winding 5, and the riding portion of the terminal wire 7 is in a state of projecting in the outer diameter direction from the outer peripheral diameter of the ring-shaped winding 5 by the wire diameter of the wire to be used. 8 is generated as described above. Then, the winding holding means 9 provided with the winding 5 is inserted into the cylindrical ferrite core 1 and then expanded to attach the winding 5 to the winding groove 2 in the cylindrical ferrite core 1. FIG. 2 is an enlarged view of a main part (an enlarged view of a portion corresponding to the portion A in FIG. 1) at the time.

As shown in FIG. 2, the winding 5 wound around the winding holding means 9 with a predetermined diameter is plastically deformed by expansion and mounted in the winding groove 2 and its terminal wire. 6 and 7 are also positioned in the terminal wire drawing slit groove 3, but the bottom wire 2a of the winding groove 2 and the side surface 3a of the terminal wire drawing slit groove 3 intersect the terminal wire of the core corner. Since the chamfered portion 4 is provided on the pull-out side of the terminal 7 as described above, the terminal wire 7 is dragged in when the coil holding means 9 is expanded to cause plastic deformation (in the direction of the arrow in FIG. 2). On the other hand, the protruding portion 8 of the wire rod of the terminal portion does not come into contact with the corner portion of the core, so that the wire rod can be smoothly mounted without being damaged.

FIG. 3 shows a second embodiment of the present invention,
In this embodiment, the chamfered 4 part provided so as to cut the core corner formed by intersecting the bottom surface 2a of the winding groove 2 and the side surface 3a of the terminal wire drawing slit groove 3 is provided for the winding. It is formed so as to correspond to the respective lead-out sides of the two terminal wires 6 and 7 of the winding wire 5 which is mounted in the groove 2. By doing so, the directionality of the winding wires 5 wound around the outer peripheral surface of the winding holding means 9 on the side of the terminal wires 6 and 7 on which the winding wires 5 are ridden does not matter, thus improving workability. ..

FIG. 4 shows a third embodiment of the present invention.
In the present embodiment, the width of the chamfered portion 4 in the first and second embodiments is the same as the groove width of the winding groove 2, whereas the groove width of the chamfered portion 4'is set to the winding groove. The groove width is larger than the groove width of 2. By doing so, the base end bent portion of the terminal wire 7 curves relatively gently and extends from the winding groove 2 to the terminal wire drawing slit groove 3, which may further damage the wire rod. Disappears. Furthermore, when the chamfered portion 4 is formed by post-processing, some dimensional error is allowed, which is excellent in workability.

Although the linear chamfered portion 4 is provided as the corner-removed portion in each of the above-mentioned embodiments, it goes without saying that the corner portion of the core may be curved.

[0014]

As described above, according to the present invention, it is possible to prevent the wire rod from being damaged at the portion where the terminal wire is drawn out from the winding groove, so that the wire can be expanded in the radial direction without quality problems. It is possible to directly mount the winding in the groove by using the winding holding means, thereby enabling efficient and reliable automatic mounting of the winding, and obtaining an inexpensive cylindrical rotary transformer. You can

[Brief description of drawings]

FIG. 1 is a cutaway perspective view of a cylindrical ferrite core for a cylindrical rotary transformer according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion corresponding to a portion A of FIG. 1 in a state where a winding is attached.

FIG. 3 is a cutaway perspective view of a cylindrical ferrite core for a cylindrical rotary transformer according to a second embodiment of the present invention.

FIG. 4 is a cutaway perspective view of a cylindrical ferrite core for a cylindrical rotary transformer according to a third embodiment of the present invention.

FIG. 5 is a perspective view of the winding holding means in a state in which winding is applied.

FIG. 6 is a cutaway perspective view of a conventional cylindrical ferrite core for a cylindrical rotary transformer.

[Explanation of symbols]

 1 Cylindrical ferrite core 2 Winding groove 2a Bottom surface 3 Terminal wire drawing slit groove 3a Side surface 4, 4'Chamfered portion 5 Winding 6, 7 Terminal wire 8 Wire rod protrusion 9 Winding holding means 10 Winding guide

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Kanda 33-12 Minamieicho, Tottori City, Tottori Prefecture Hitachi Felite Co., Ltd. Tottori Factory (72) Inventor Makoto Ota 33-12 Minamieicho, Tottori City, Tottori Prefecture Hitachi Ferrite Tottori Factory Co., Ltd.

Claims (3)

[Claims] 1. A first cylindrical ferrite core in which a plurality of grooves are formed in a circumferential direction of an outer peripheral surface and windings are arranged in the grooves, and an outer peripheral surface of the first cylindrical ferrite core and a predetermined shape. A second cylindrical ferrite core in which a plurality of grooves are formed in the circumferential direction of the inner peripheral surface, and windings are arranged in the grooves. In a cylindrical rotary transformer for transmitting a signal by electromagnetic coupling between the windings of the first and second ferrite cores, in the bottom surface of the circumferential groove of the inner peripheral surface of the second cylindrical ferrite core and the groove. In order to guide the terminal wire of the arranged winding to the end face side of the cylindrical ferrite core, the side faces of the slit grooves formed deeper than the circumferential groove in the axial direction of the inner peripheral surface intersect. At least the terminal wire of the winding is actually derived from the plurality of core corners A corner is cylindrical rotary transformer characterized in that it is formed as a corner removed site. 2. The corner removing portion according to claim 1, wherein at least a circumferential groove among a plurality of core corners formed by intersecting a bottom surface of the circumferential groove and a side surface of an axial slit groove. A cylindrical rotary transformer, characterized in that it is formed at a corner portion of a core on a side from which a terminal wire located at an outer diameter of a circumferential coil portion of a winding disposed on a side is led out. 3. The corner removing portion according to claim 1, wherein the corner removing portion has a circumferential groove on an extension line including a core corner portion intersecting a bottom surface of the circumferential groove and a side surface of the axial slit groove. A cylindrical rotary transformer characterized by being formed with a width that does not necessarily match the groove width.