JPH06274802A - Rotary magnetic head device - Google Patents

Abstract

PURPOSE:To accurately position a core to a drum by integrally molding either one drum of a fixed drum or a rotary drum with the core of a rotary transmission. CONSTITUTION:The fixed drum 10 is molded integrally with the fixed-side core 11 constituting the fixed-side rotary transmission by outsert molding, for example. The fixed drum 10 is molded out of resin containing carbon, for example, and imparted with electrical conductivity to serve earthing. The fixed drum 10 is outsert-molded with the core 11 after wirings 12, 13 are wound in the grooves 11a, 11b of the fixed-side core 11 at the time of assembling the fixed drum 11. At this time, an engagement part projecting outward from the peripheral edge of the core 11 is buried in the main body of the fixed drum 10, and thus, the core 11 is positioned precisely to the drum 10 to be fixed and held. In such a manner, the assembly of the drum 10 is completed within a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary magnetic head device in a VTR, DAT or the like, and more particularly to a rotary magnetic head device having a rotary transformer as a signal transmitting means between a stationary drum and a rotating drum. It is about.

[0002]

2. Description of the Related Art Conventionally, a rotary magnetic head device used for VTR, DAT, etc. is constructed as shown in FIG. 6, for example. In the figure, a rotary magnetic head device 1 includes a fixed drum 2 and a rotary drum 3 rotatably supported with respect to a center line O of the fixed drum. On the inner bottom surface of the fixed drum 2, a fixed core 4 that constitutes a rotary transformer is attached concentrically with the fixed drum 2. Further, at the lower end of this rotating drum, a core 4 on the fixed side, which is attached to the fixed drum 2 at the time of assembly,
On the other hand, the rotation-side core 5 that constitutes the rotary transformer is mounted concentrically with the rotary drum 3 so as to face it from above.

The stationary side core 4 and the rotating side core 5 are provided with windings 6 and 7 in grooves 4a and 5a provided along the circumferential direction, respectively.

According to the rotary magnetic head device 1 thus constructed, the rotary drum 3 is rotated with respect to the fixed drum 2 during reproduction, and the magnetic head provided on the rotary drum 3 (see FIG. The signal detected by (not shown) is input to the winding 7 of the core 5 on the rotating side of the rotary transformer.
As a result, a signal is generated in the winding 6 of the core 4 on the fixed side of the rotary transformer, and this signal is output to the outside.

During recording, an electric signal from a control circuit (not shown) or the like is input to the winding 6 of the core 4 on the fixed side of the rotary transformer. As a result, a signal is generated in the winding 7 of the core 5 on the rotary side of the rotary transformer, and this signal is output to the magnetic head to write on the magnetic tape.

[0006]

In the rotary magnetic head device 1 as described above, the cores 4 and 5 of the rotary transformer are fixed drum 2 and rotary drum 3, respectively.
Again, after being accurately positioned, it is attached in place with an adhesive. However, if dust or the like has entered the core mounting surfaces of the fixed drum 2 and the rotary drum 3, the precision of mounting the cores 4 and 5 will decrease due to the dust and the like.

Further, since the cores 4 and 5 are fixed and held by the adhesive, the primer is first applied, then the adhesive is applied and the pressure is applied in the adhering step, and thereafter the adhesive is applied. Needs to be dried. For this reason, the bonding process itself takes time and the assembly time becomes long. Further, there is a problem that the quality control of the adhesive is required and the cost becomes high.

In view of the above points, the present invention provides a rotary magnetic head device which can be assembled easily and in a short time with a simple structure, can be manufactured at low cost, and has high assembly accuracy. Has an aim.

[0009]

According to the present invention, the above object includes a fixed drum and a rotary drum rotatably supported with respect to the fixed drum. A signal is input and output from the fixed drum side to the head through a rotary transformer.
In the rotary magnetic head device, at least one of the fixed drum and the rotary drum is integrally formed with the core of the rotary transformer by the rotary magnetic head device.

In the rotary magnetic head device according to the present invention, preferably, the inner peripheral edge of the core of the rotary transformer is provided with an engaging portion to be embedded in the drum.

In the rotary magnetic head device according to the present invention, preferably, the outer peripheral edge of the core of the rotary transformer is
It has an engaging part to be embedded in the drum.

[0012]

According to the above construction, since the fixed drum or the rotary drum is integrally formed with the core constituting the rotary transformer, the core is positioned and fixedly held at a predetermined position with respect to the drum. Become.

Further, when the inner peripheral edge or the outer peripheral edge of the core of the rotary transformer is provided with an engaging portion to be embedded in the drum, the engaging portion is formed in the drum by integral molding with the drum. Embedded and fixedly held.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to FIGS. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 shows an embodiment of a fixed drum of a rotary magnetic head device according to the present invention. In FIG.
The fixed drum 10 is formed integrally with the fixed core 11 that constitutes the fixed rotary transformer by, for example, outsert molding.

Here, the fixed core 11 is constructed as shown in FIG. That is, in FIG. 2, the core 11 on the fixed side has a disc shape, and has annular grooves 11a and 11b formed concentrically on the upper surface thereof.
Is equipped with. Windings 12 and 13 are wound in the grooves 11a and 11b, respectively. Further, preferably, the fixed-side core 11 has an engaging portion 11 c whose outer peripheral edge projects outward and is embedded in the fixed drum 10.

Further, preferably, the fixed drum 10 is provided with conductivity by being molded from a resin mixed with carbon or the like, for example. As a result, the fixed drum 10 can be grounded similarly to the drum which is conventionally made of aluminum or aluminum alloy.

When assembling the fixed drum 10 as described above, the winding 1 is placed in the grooves 11a and 11b of the core 11 on the fixed side.
After winding 2 and 13, the fixed drum 10 is outsert-molded with respect to the core 11.

At this time, the engaging portion 11c projecting outward from the outer peripheral edge of the core 11 is embedded in the main body of the fixed drum 10 as shown in FIG. 1 (B). As a result, the core 11 on the fixed side of the fixed drum 10 is accurately positioned and fixedly held. In this way, with a simple configuration, in a short time,
Assembly of the fixed drum 10 is completed. Further, as compared with the conventional case where the core is bonded to the drum, the assembling accuracy can be improved.

FIG. 3 shows an embodiment of the rotary drum of the rotary magnetic head device according to the present invention. In the figure, the rotary drum 20 is integrally formed with the rotary core 21 that constitutes the rotary transformer on the rotary side by, for example, outsert molding.

Here, the rotating core 21 is constructed as shown in FIG. In the figure, the core 21 on the rotating side
Has a disc shape, and its upper surface is
It is provided with annular grooves 21a and 21b formed concentrically. In the grooves 21a and 21b, the windings 22 and
23 is wound. Furthermore, the core 21 on the fixed side
Has an engaging portion 21 c whose inner peripheral edge projects inward and is to be embedded in the rotary drum 20.

Further, the rotary drum 20 is made conductive, for example, by molding it from a resin mixed with carbon or the like, like the fixed drum 10 of FIG. As a result, the rotary drum 20 can be grounded similarly to the drum which has been conventionally made of aluminum or aluminum alloy.

According to the rotary drum 20 having the above-described structure, the grooves 21a, 2 of the core 21 on the rotating side are assembled during assembly.
After winding the windings 22 and 23 in 1b, the rotary drum 20 is outsert-molded with respect to the core 21. At this time, the engaging portion 21c protruding inward from the inner peripheral edge of the core 21
Will be embedded in the main body of the rotary drum 20, as shown in FIG. As a result, the rotating drum 2
On the other hand, since the core 21 on the rotating side is accurately positioned and fixedly held with respect to 0, the assembly accuracy is improved as compared with the conventional case where the core is bonded to the drum.

In the above embodiment, the core 21
Has an engaging portion 21c on its inner peripheral edge, but as shown in FIG. 5, the engaging portion 21d protruding outward also on the outer peripheral edge.
May be provided. The core 21 can also be used as the core 11 on the fixed side. Therefore, in this case, it is not necessary to prepare two types of cores 11 and 21, so that the cost is reduced.

In the illustrated embodiment, a rotary transformer having a disk-shaped core has been described, but the present invention is not limited to such a core and can be applied to a cylindrical core. That is, one cylindrical core may be integrally formed with the rotary drum, and the other cylindrical core may be integrally formed with the fixed drum.

[0026]

As described above, according to the present invention, since the fixed drum or the rotating drum is integrally formed with the core constituting the rotary transformer, the drum can be attached to the drum without using an adhesive. On the other hand, the core is accurately positioned and fixedly held at the predetermined position. Therefore, the step of adhering the core to the drum becomes unnecessary, and the assembly time is shortened. Further, the quality control of the adhesive becomes unnecessary, and the cost is reduced. In addition, the inner peripheral edge or the outer peripheral edge of the core of the rotary transformer is
When the engaging portion to be embedded in the drum is provided, by integrally molding with the drum, the engaging portion is securely fixed and held by being embedded in the drum.

[Brief description of drawings]

FIG. 1A is a schematic sectional view and FIG. 1B is a partially enlarged sectional view showing an embodiment of a fixed head of a rotary magnetic head device according to the present invention.

2 (A) is a plan view and FIG. 2 (B) is a cross-sectional view showing a core on the fixed side attached to the fixed head of FIG.

3A is a schematic sectional view and FIG. 3B is a partially enlarged sectional view showing an embodiment of a rotary head of a rotary magnetic head device according to the present invention.

FIG. 4 is a cross-sectional view showing a rotation-side core attached to the rotary head of FIG.

5 is a cross-sectional view showing a modified example of the core of FIG.

FIG. 6 is an exploded perspective view showing the structure of an example of a conventional rotary magnetic head device.

[Description of Reference Signs] 10 fixed drum 11 fixed side core 11c engaging part 12 winding 13 winding 20 rotating drum 21 rotating side core 21c engaging part 21d engaging part 22 winding 23 winding

Claims (3)

[Claims] 1. A fixed drum and a rotary drum rotatably supported with respect to the fixed drum, and a signal from a fixed drum side to a magnetic head mounted on the rotary drum via a rotary transformer. In the rotary magnetic head device for inputting and outputting, at least one of the fixed drum and the rotary drum is formed integrally with the core of the rotary transformer. 2. The rotary magnetic head device according to claim 1, wherein an inner peripheral edge of the core of the rotary transformer is provided with an engaging portion to be embedded in the drum. 3. The rotary magnetic head device according to claim 1, wherein an outer peripheral edge of the core of the rotary transformer is provided with an engaging portion to be embedded in the drum.