JPH08740Y2 - Rotary transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rotary transformer used in a rotary magnetic head device such as a video tape recorder or a digital audio tape recorder.

[Outline of device]

The present invention relates to a rotary transformer in which a coil is housed in a winding groove concentrically provided on one side surface of a magnetic core and adhered with an adhesive. It is intended to prevent the adhesive from leaking to the facing surfaces of the magnetic cores arranged so as to face each other, by providing the recesses for escaping the adhesive to expand the width.

[Conventional technology]

The rotary transformer is widely used as a connecting means for transmitting a signal obtained by a rotary magnetic head provided on the rotary side in a rotary magnetic head device such as a video tape recorder or a digital audio tape recorder to a fixed side circuit. There is.

Generally, this rotary transformer is composed of a rotor and a stator formed by winding a coil around each winding groove provided concentrically on one side surface of a substantially disk-shaped magnetic core according to the number of channels. They are arranged to face each other with a minute gap. Then, by electromagnetic coupling between each coil of the rotor provided on the rotating side and the stator provided on the fixed side, for example, a rotating magnetic head connected to the rotor and a reproducing circuit connected to the stator are connected, Video signals and digital audio signals are transmitted.

By the way, in order to fix the coil to the winding groove, an adhesive is dropped or applied to the winding groove at several points or the whole, and the coil is mounted and fixed on the adhesive.

However, in order to secure the fixing of the coil,
If the necessary and sufficient adhesive is applied to the winding groove, excess adhesive will overflow from the winding groove when the coil is mounted in the winding groove, and the excess adhesive will be applied to the facing surface of the magnetic core. The problem of overflowing occurs. Therefore, it is necessary to remove the adhesive that has overflowed to the facing surface of the magnetic core, which hinders the improvement of productivity.

[Problems to be solved by the device]

The present invention has been proposed in view of such a conventional situation, and prevents the adhesive from overflowing to the facing surfaces of the magnetic cores that are arranged to face each other, and is a highly productive rotary that does not require a post-process. The purpose is to provide a transformer.

[Means for solving the problem]

In order to achieve the above-mentioned object, the rotary transformer of the present invention has a coil housed in a winding groove concentrically provided on one side of a magnetic core and bonded with an adhesive. The wall is provided with a recess for escaping the adhesive so as to expand the groove width.

[Action]

In the rotary transformer of the present invention, since the recesses for escaping the adhesive are provided on both side walls of the winding groove for winding the coil so as to expand the groove width of the winding groove, the coil is wound. When the adhesive is applied to the groove, the excess adhesive of the adhesive applied in the winding groove flows into the adhesive escape recess without overflowing to the facing surface of the magnetic core.

〔Example〕

Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings.

As shown in FIG. 1, the rotary transformer of the present invention comprises a substantially disk-shaped magnetic core 1 and coils 2, 3 and a short ring 4 which are fitted and arranged in the magnetic core 1, respectively. .

The magnetic core 1 has annular winding grooves 5 and 6 in the same number as the number of coils corresponding to the required number of channels (two channels in this embodiment) on one side surface 1a. Above winding groove 5,6
Is a concentric circular groove having a substantially U-shaped cross section, in which coils 2 and 3 formed by forming the copper wire or the like in a substantially annular shape are fitted and arranged.

Further, between the winding grooves 5 and 6, a short ring 4 for preventing mutual interference between the coils 2 and 3 fitted and arranged in the winding grooves 5 and 6 and for preventing noise and inductance change. A short ring groove 7 for fitting and arranging is provided. This short ring groove 7 is also the winding groove 5,
Similar to 6, it is formed as a groove having a substantially U-shaped cross section so as to be concentric with these winding grooves 5, 6.

The magnetic core 1 configured as described above is manufactured, for example, by pressing magnetic powder such as ferrite with a die and then firing this at a high temperature. Alternatively, inject a ferrite powder mixed with an appropriate amount of binder (mainly 15-20% thermoplastic resin such as polypropylene or low-molecular acrylic) into a mold of an injection molding machine having the same structure as plastic molding and inject it. It is made by molding.

In particular, when injection molding is used, the ferrite powder is uniformly pressed in all directions in the mold, so residual stress is less likely to occur, and the distribution of the packing density becomes uniform, causing cracks, etc. The advantage is that the occurrence of In addition, the injection molding has an advantage that a very fine shape can be manufactured and is suitable for manufacturing a core having a complicated shape.

On the other hand, the coils 2 and 3 are housed in the winding grooves 5 and 6, respectively, and are bonded by the adhesive applied to the winding grooves 5 and 6. Similarly, short ring 4
Are accommodated in the short ring groove 7 and adhered by the adhesive applied in the short ring groove 7.

In particular, in this embodiment, as shown in FIG. 2, the winding grooves 5, 6 are formed in the side walls 5a, 5b, 6a, 6b of the winding grooves 5, 6, respectively.
The recesses 8 and 9 for escaping the adhesive are provided so as to expand the groove width. The recesses 8 and 9 for escaping the adhesive are
Adhesive 10 dropped to temporarily fix 2, 3 to the winding grooves 5, 6.
Is provided in the vicinity of the peripheral edge of the magnetic core 1 and has a role of accommodating the excess adhesive so that the adhesive 10 does not overflow to the one side surface 1a of the magnetic core 1 when the coils 2 and 3 are mounted.

The adhesive escape recesses 8 and 9 will be described by taking the recess 9 formed on the outermost periphery of the magnetic core 1 as an example. As shown in FIG. A part of both side walls 6a, 6b of the line groove 6 is formed by scraping off in a substantially arcuate plane shape so as to widen the groove width. The adhesive escape recess 9 is a so-called blind hole that is formed to a position deeper than the bottom surface 6c of the winding groove 6 and does not reach the other side surface 1b.

The recess 9 for escaping the adhesive may be a so-called through hole that penetrates to the side surface 1b. In addition, the recess 9 for escaping the adhesive can be easily manufactured by injection molding, which can manufacture a fine shape and is suitable for manufacturing a complicated shape.

In addition, the recess 9 for escaping the adhesive is formed by sandwiching the adhesive 10 that is dropped to trap the excess adhesive,
Are provided at positions opposite to both side walls 6a and 6b. Further, the recess 9 for escaping the adhesive is at least the coil 2
The number of adhesives 10 required to securely fix the wire in the winding groove 6
It is provided on both sides of each adhesive 10 according to the number of drops.

In this way, since the recesses 9 for escaping the adhesive such as expanding the groove width are provided on both side walls 6a, 6b of the winding groove 6, when the coil 2 is mounted in the winding groove 6, it becomes an excess. Further, the adhesive 10 does not flow into the recess 9 for escaping the adhesive and does not overflow to the one side surface 1a which is the facing surface of the magnetic core 1. In addition, the adhesive 10 that has flowed into the recess 9 for escaping the adhesive
Has a function of bonding the coil 2, so that a stronger bonding strength can be expected due to an increase in the bonding area.

In the present embodiment, the recess for the escape of the adhesive is provided with the magnetic core 1.
Although the concave portion 9 provided on the outermost periphery of is described as an example,
The innermost peripheral recess 8 for escaping the adhesive is also formed in the same manner as the recess 9 provided on the outermost rim, so that when the coil 3 is mounted, the excess adhesive 10 flows into the recess 8 for escaping the adhesive. Has become. A similar recess 11 for escaping the adhesive is also provided in the short ring groove 7, and the short ring 4
By mounting, the excess adhesive 10 also flows into the recess 11 for escaping the adhesive.

[Effect of device]

As is clear from the above description, in the rotary transformer of the present invention, the recesses for escaping the adhesive are provided on both side walls of the winding groove for winding the coil so as to expand the groove width. Therefore, when the coil is mounted, the excess adhesive can be made to flow into the recess for the escape of the adhesive, and the overflow of the adhesive to the facing surface of the magnetic core can be prevented. Therefore, it is not necessary to remove the adhesive that has overflowed to the facing surface of the magnetic core, the number of steps can be reduced, and the productivity can be improved.

Further, since the coil can be bonded by the adhesive that has flowed into the recess for escaping the adhesive, not only the bonding stability is improved due to the increased bonding area, but also the bonding strength is significantly improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a rotary transformer to which the present invention is applied, FIG. 2 is an enlarged perspective view of an essential part of a magnetic core, and FIG. 3 is an enlarged view showing a recess for an adhesive escape. FIG. 1 ... Magnetic core 2,3 ... Coil 4 ... Short ring 5,6 ... Winding groove 7 ... Short ring groove 10 ... Adhesive agent 8,9,11 ... Adhesive agent recess

Claims (1)

[Scope of utility model registration request] 1. A coil is housed in a winding groove concentrically provided on one side surface of a magnetic core and is bonded with an adhesive. The winding grooves are bonded to both side walls so as to expand the groove width. A rotary transformer having a recess for escaping the agent.