JPH0723949Y2 - Coaxial rotary transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to an improvement of a coaxial rotary transformer used for magnetic recording and reproducing such as a video tape recorder (hereinafter abbreviated as VTR). It is a thing.

(Prior Art) FIG. 6 shows a conventional example of a coaxial rotary transformer used in a VTR or the like. In this conventional example, a plurality of pairs of coils are wound around each signal transfer surface of a pair of coaxially-assembled cylindrical core bodies, and for example, a lead terminal relating to a fixed-side cylindrical core body located inside is It is a coaxial rotary transformer of a type in which it is entwined with a terminal member of a flange-shaped circular terminal block formed at the lower end of the fixed core body.

30 is the fixed side core body of the conventional coaxial rotary transformer,
Reference numeral 31 denotes a cylindrical core having an outer peripheral surface serving as a signal transmitting / receiving surface, 32 denotes a terminal block integrally formed at a lower end portion of the cylindrical core 31, and 33 stands vertically below the terminal block 32. The terminal member 34 is an appropriate printed circuit board. The number of coils C (three in this example) corresponding to the required channels are wound around the signal transfer surface of the cylindrical core 31. Then, the lead terminal E relating to these coils C
However, the structure is such that it is entwined with the terminal member 33.

The fixed core body 30 is assembled with a rotary core body (not shown) having a similar signal transmitting / receiving surface formed on the inner peripheral surface thereof, and then the terminal member 33 with the lead terminal E entwined is attached thereto. The printed board 34 is appropriately inserted into the mounting hole 35, and then subjected to a predetermined soldering process so that the both are electrically and mechanically coupled.

By the way, in recent years, VTRs are required to be downsized and have multiple channels. In the structure of the coaxial rotary transformer described above, for example, the dimension from the upper end of the cylindrical core 31 to the lower end of the terminal member 33 is the coaxial rotary transformer. And the effective dimension of the signal transmitting / receiving surface represented by the height h1 is considerably narrower than the total height H of the transformer.

(Problems to be solved by the invention) As a result, when using this in a VTR, it was difficult to increase the number of channels due to the limited installation space on the VTR side.

An object of the present invention is to provide a coaxial rotary transformer having a small total height H and capable of realizing multichannels.

[Structure of the Invention] (Means for Solving the Problems) According to the structure of claim 1 of the present invention, a plurality of pairs of coils are wound around each signal transmitting / receiving surface of a pair of coaxial cores that are coaxially combined. In a coaxial type rotary transformer of a type in which a lead end relating to a cylindrical core located inside or outside is entwined with a terminal portion of a collar-shaped terminal block formed on the end face side of the inside or outside cylindrical core, The terminal block is formed as a plate-shaped member, the terminal portion is formed to project on the side surface of the terminal block, the end surface of the cylindrical core on the terminal block side is arranged to project from the surface of the terminal block, The lead end of the coil relating to the inner or outer cylindrical core is taken out from the peripheral surface of the inner or outer cylindrical core along at least one plane of the terminal block and is entangled with the terminal portion.

According to a second aspect of the present invention, in the coaxial rotary transformer according to the first aspect, one concave surface of the terminal block is provided with a concave first adhesive reservoir for receiving an adhesive before curing. A concave second adhesive reservoir for receiving the flow-down adhesive is provided on the other flat surface of the terminal block, and the cylindrical core and the terminal block are bonded with the adhesive.

(Operation) Based on this configuration, the operation according to claim 1 of the present invention is to send and receive a signal to and from the entire height of the rotary transformer by guiding the lead end of the coil installed in the inner or outer core body to the side of the core body. The height ratio occupied by the effective dimensions of the surface is increased. Since the end surface of the cylindrical core on the terminal block side is projected from the terminal block, this end surface can be used as a reference for assembly, so that a coaxial rotary transformer with high signal transmission reliability can be obtained.

Further, according to the second aspect of the present invention, when the cylindrical core and the terminal block are bonded together, the terminal block is provided with a notch provided in the end surface of the cylindrical core on the terminal block side so that the first bonding pool is the upper surface. Then, the adhesive before curing is applied to the first adhesive pool. Then, the adhesive flows into the clearance between the cylindrical core and the terminal block. Furthermore, the excess adhesive accumulates in the second adhesive pool on the opposite side of the first adhesive pool due to the capillary phenomenon and then cures, so that the adhesive can be prevented from protruding to the cylindrical signal transfer surface. The effective dimension of the signal transfer surface can be secured.

(Embodiment) Hereinafter, the present invention will be described with reference to the drawings. An originally coaxial rotary transformer is a pair of core bodies, that is, an inner core body and a pair of core bodies that are relatively rotatably assembled by means known per se. Although it is composed of an outer core body, in the following description, assuming an example in which the inner core body is the fixed side,
Based on this, the present invention will be described in detail.

1 to 4 are views showing an inner core body of a coaxial type rotary transformer according to the present invention. FIG. 1 is a sectional view, FIG. 2 is a plan view, FIG. 3 is a side view, and FIG. 3A is a rear view, and FIG. 3B is a detailed view of the Y portion of FIG.

1 is an inner core body which is a fixed side, 1'is an outer core body which is a rotating side (shown by an imaginary line), 2 is a cylindrical core made of an appropriate magnetic material, and 10 is a disk made of an appropriate insulating material. -Shaped terminal block, 11 to 14 (11a to 14a, 11b to 14b, 11c, 12c) is integrally molded with the terminal block 10, the terminal portion 15a to 15c protruding from the outer peripheral surface of the terminal block 10. Is also the terminal block
A mounting portion that is integrally molded with the terminal block 10 and is provided so as to project from the inner peripheral surface of the terminal block 10, and 20 is a flexible printed circuit board that is connected to the terminal portions 11 to 14 by solder 23.

First, the cylindrical core 2 will be described in detail.

Five coil winding grooves 3a to 3e around which the coil C is wound are provided on the signal transmitting / receiving surface on the outer peripheral surface of the cylindrical core 2.
The gap between the grooves 3a to 3e is maintained to the extent that crosstalk does not occur between the channels.

Further, for example, at three locations on the outer peripheral surface, which are divided into three equal parts, as shown in FIG. 2, linear shapes extending parallel to the axis of the cylindrical core 2 to the upper and lower end surfaces 2a, 2b are formed. Lead terminal take-out grooves 5a to 5c are formed. The depth of these linear lead terminal take-out grooves 5a to 5c is set to be slightly deeper than the depth of the coil winding grooves 3a to 3e described above, and the width thereof is the lead terminal of each coil C (winding start terminal). The terminal end) E (see FIG. 1) is set to a width such that one set or several sets can be collectively taken out.

Further, the terminal block 10 is provided on the end surface 2b of the cylindrical core 2 on the terminal block 10 side.
Are provided with notches 4a to 4c for mounting and positioning. The cutouts 4a to 4c are provided at three locations on the circumference of the core 2 that are equally divided into three parts. The depth of the cutouts 4a to 4c is the terminal block.
The size is such that the terminal block 10 is buried about 0.01 to 0.3 mm from the end face 2b when the 10 is mounted in the notches 4a to 4c (shown by h4 in FIG. 1). That is, the end surface of the cylindrical core is installed so as to protrude from the end surface of the terminal block.

By the way, as shown in FIG. 1, the dimension between the signal transmitting / receiving surfaces of the inner core body 1 and the outer core body 1'shown by an imaginary line has a very narrow positional relationship of 0.1 mm or less in terms of signal transmission efficiency. A high assembly precision is required for assembling the inner core body 1 and the outer core body 1 '. Since the cylindrical core 2 is made of an appropriate magnetic material, the dimensional accuracy can be easily obtained by machining as compared with the terminal block made of an insulating material. Therefore, for example, the right angle accuracy of the outer surface of the cylindrical core 2 which is a signal transmitting / receiving surface with respect to the end surface 2b is good. Therefore, when the end surface 2b is located outside the terminal block 10 in the axial direction, the end surface 2b can be used as a reference for assembling the coaxial rotary transformer, so that the reliability of signal transfer can be ensured.

Then, the cylindrical core 2 having such a configuration and the terminal block 10 are joined by an adhesive means described later.

Next, the terminal block 10 will be described in detail.

The material of the terminal block 10 needs to be an insulating material having heat resistance so that the soldering work can be performed at the terminals 11 to 14.
As an example of such a material, a resin material containing a liquid crystal polymer as a basic component is preferable. This material has good heat resistance and can sufficiently withstand the heat even when it is dipped in a solder bath at 400 ° C. for soldering.

Further, the ten terminal portions 11 to 14 have a rod shape that is as thin as possible so as to maintain sufficient strength for entwining the lead terminal E of the coil C.

Further, the protruding positions of the terminal portions 11 to 14 are, for example, positions corresponding to the radial lead terminal take-out grooves 5a to 5c, but they may be selected at slightly different positions in plan view.

Further, the terminal block 10 has three lead terminal take-out grooves 5a.
Cutouts 17a to 17c are formed to reach the side surface in a radial manner from a position corresponding to 5 to 5c as a starting point.

Then, ten terminal portions 11 to 14 are formed on both sides of the crossing end portion between each of the cutout portions 17a to 17c and the side surface.

Further, the cutout portion 4a of the cylindrical core 2 shown in FIG. 4 (a).
The mounting positions of the mounting portions 15a to 15c mounted on
The positions correspond to the cutouts 17a to 17c shown in the figure.
By doing so, the strength of the roots of the cutouts 17a to 17c is secured.

Further, concave portions 18a, which are concave first adhesive pools, are provided at three locations on the end surface 2b side of the cylindrical core 2 of the terminal block 10. On the surface opposite to the surface on which the recess 18a is provided, three chamfered portions 18b, which are second adhesive pools, are provided as shown in FIG.

On the end face 2b side of the cylindrical core 2 of the terminal block 10, as shown in FIG. 4 (a), the coil C wound around the grooves 3a to 3e is passed through the linear lead terminal take-out grooves 5a to 5c. A convex portion 16 for folding back to the terminal portions 11 to 14 is provided so as to project in the vicinity of the mounting portions 15a to 15c.

Next, the flexible printed circuit board 20 will be described in detail.

The flexible printed circuit board 20 includes a flexible insulating thin plate (flexible sheet) 21a made of a known insulating material (preferably, a resin material containing polyimide as a basic component) and an upper surface thereof, for example. It is composed of a conductive path pattern 22 formed by a printing method and an insulating thin plate 21b made of the same material as the insulating thin plate 21a for protecting the conductive path pattern 22.

In this case, the insulating thin plate 21 is formed such that the mounting portion 20a on which the fixed side core body 1 is mounted has a substantially circular shape with a size exceeding the tips of the terminal portions 11 to 14, and The other end portion 20b located on the side opposite to the placing portion 20a is formed in, for example, one laterally widening shape. The intermediate portion 20c is formed as a strip having an arbitrary length.

On the other hand, the conductive path pattern 22 is formed of a flexible conductor that can follow the flexible function of the insulating thin plates 21a and 21b.

Then, in the mounting portion 20a, a group of connecting conductive portions 22b is formed at each position corresponding to the terminal portions 11 to 14 of the inner core body 1 to be mounted, and in addition to the mounting portion 20a, At the end portion 20b, a group of terminal conductive portions (external extraction electrodes) 22a for connecting to a device to be attached (not shown) is formed. Further, the intermediate portion 20c is formed with a conductive path pattern 22 for electrically connecting the groups 22a and 22b.

Next, the wiring path of the coil C will be described in detail.

The terminal E of the coil C wound around the coil winding grooves 3a to 3e is collected one by one or in several sets, passes through the linear lead terminal take-out grooves 5a to 5c, and is further connected to the terminal block 10 and the flexible print. The terminal portions 11 to 14 via the substrate 20
It is entangled. The terminal E of the coil C twisted by the terminal portions 11 to 14 is connected to the group of connection conductive portions 22b by solder 23. Further, since the coil terminal E is sufficiently thinner than the dimension h4 in FIG. 1, the flexible printed circuit board 20 can be used in correspondence with the coil terminal E even if the coil C take-out path is not provided on the terminal block 10 side. Curved, yet substrate 20
Does not extend axially outward from the end surface 2b.

Joining between the cylindrical core 2 and the terminal block 10 will be described with reference to FIGS. 4 (a) and 5. FIG. 5 shows a state in which the cylindrical core 2 is reversed with respect to FIG.

First, as shown in FIG. 4 (a), the cutout portion of the cylindrical core 2 is formed.
The mounting portions 15a to 15c of the terminal block 10 are mounted on 4a to 4c. Next, the adhesive before curing is injected into the concave groove 18a which is the first adhesive pool of the terminal block 10 (FIG. 5 (a)). Then,
As shown in FIG. 5 (b), the adhesive enters the gap between the cylindrical core 2 and the terminal block 10 by the capillary phenomenon. Then, as shown in FIG. 5 (c), the excess adhesive is the chamfered portion 18b which is the second adhesive pool on the opposite side of the concave groove 18a.
It flows to the pool where it pools and cures. This adhesive does not drip to the signal transfer surface side by the chamfered portion 18b.

Since the present invention is configured as described above, it has the following effects.

(A) Since the end surface 2b of the cylindrical core 2 on the side of the terminal block 10 is projected from the terminal block 10, this end surface 2b can be used as a reference when assembling the coaxial rotary transformer, so that reliability of signal transmission can be improved. The property is improved.

(B) A concave groove when joining the cylindrical core 2 and the terminal block 10.
Since the chamfered portion 18b is provided on the opposite side of 18a, the adhesive
Since 19 does not sag on the signal transmitting / receiving surface side, the effective dimension of the signal transmitting / receiving surface can be stabilized.

(C) Since the flexible printed circuit board 20 is used for the cables led out from the terminals 11 to 14, the total height H of the coaxial rotary transformer can be made small.

Although several embodiments have been described above, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.

For example, the number of coil winding grooves formed in the inner core body can be determined as necessary.

Further, as for the shape and structure of the inner core body, an appropriate one can be adopted. Further, in the above-mentioned embodiment, the case where the inner core body is the fixed side has been described, but the same operation is performed even when the outer core body (not shown) is the fixed side.
The effect can be obtained.

Further, although the concave groove 18a and the chamfered portion 18b, which are adhesive pools for joining the cylindrical core and the terminal block, are provided on the terminal block 10 side, they may be provided on the cylindrical core 2 side.

[Advantages of the Invention] As described above, when using claim 1 of the present invention, the ratio of the effective dimension of the signal transmitting / receiving surface to the total height of the coaxial rotary transformer can be increased, so that the total height is small. Moreover, it is possible to provide a coaxial rotary transformer that can realize multiple channels. Further, since the end surface of the cylindrical core projects more than the end surface of the terminal block, it is possible to assemble with reference to the projecting end surface, and it is possible to secure the reliability of signal transfer.

In addition, when the second aspect of the present invention is used, in addition to the above-mentioned effects, the joint between the cylindrical core and the terminal block can be easily adhered with an adhesive agent, and the adhesive agent is not exposed on the signal transmitting / receiving surface. It is possible to provide a coaxial rotary transformer having a stable effective dimension of a signal transmitting / receiving surface.

[Brief description of drawings]

1 to 5 are views showing an inner core body on a fixed side of a coaxial rotary transformer according to the present invention. FIG. 1 is a sectional view, FIG. 2 is a plan view, FIG. 3 is a side view, and FIG. 4 (a) is a back view, FIG. 4 (b) is a detailed view of the Y portion of FIG. 4 (a), and FIGS. 5 (a) to 5 (c) are a cylindrical core and a terminal block. FIG. 6 is a side view of the inner core body on the fixed side of the coaxial rotary transformer of the conventional example, which is a working diagram showing the joining process. 1 ... Inner (fixed side) core body, 2 ... Cylindrical core, 2a, 2b ...
End face, 3a to 3e ... Coil winding groove, 4a to 4c ... Notch, 10 ...
Terminal block, 11 to 14 ... Terminal part, 15a to 15c ... Mounting part, 18a
… Concave groove (first adhesive pool), 18b… Chamfer (second)
Adhesive pool), C ... coil, E ... lead terminal.

Claims (2)

[Scope of utility model registration request] 1. A plurality of pairs of coils are wound around each signal transmitting / receiving surface of a pair of coaxially-assembled cylindrical cores, and a lead end relating to the cylindrical core located inside or outside is provided on the inside or outside. In a coaxial rotary transformer of a type entwined with a terminal portion of a flange-shaped terminal block formed on the end surface side of a cylindrical core, the terminal block is formed as a plate-shaped member, and the terminal section is formed on the side surface of the terminal block. The terminal ends of the cylindrical cores, which are formed to project, are arranged so as to project from the surface of the terminal block, and the lead terminals of the coils relating to the inner or outer cylindrical cores are formed on the inner or outer cylindrical cores. A coaxial type rotary transformer which is taken out from the peripheral surface of the terminal along at least one plane of the terminal block and is entwined with the terminal portion. 2. A concave first adhesive reservoir for receiving the adhesive before curing is provided on one flat surface of the terminal block, and a concave second adhesive reservoir for receiving the cured adhesive on the other flat surface of the terminal block. 2. The coaxial rotary transformer according to claim 1, wherein the adhesive pool is provided, and the cylindrical core and the terminal block are joined together with an adhesive.