JPH0119220Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-channel magnetic head, and more particularly to a magnetic head suitable for use in an audio stereo tape recorder.

Recently, in magnetic heads such as tape recorders, in order to reduce the number of parts, simplify assembly, and reduce assembly man-hours, wires are wound around a bobbin with external connection terminals integrated by press-fitting or molding. A structure in which the magnetic head core is fitted onto the back gap butt side of the magnetic head core is increasingly being adopted.

FIG. 1 shows an example of a conventional magnetic head of this type. In this figure, cores 1A, 1B are held by a pair of core holders 2A, 2B, respectively, and the tips of the cores 1A, 1B form a front gap 3, and the rear ends form a back gap 4. The bobbin 5 integrally has a terminal 6 for external connection, and further has a winding 7. This bobbin 5 has cores 1A, 1
When B are butted together, they are fitted onto the back gap 4 side of those cores. The core holders 2A, 2B
is inserted into the shield case 8 with the cores 1A and 1B held against each other, the front opening of the shield case 8 is filled with resin, and the tape sliding surface is polished as required.

The problem with the structure shown in FIG.
This rotation and rattling cannot be prevented simply by fitting the bobbin 5 to A and 1B. Therefore, in the configuration shown in FIG. 1, the protrusion 9 is provided on the bobbin 5, and the recess 10 that fits into the protrusion 9 is provided on the core holders 2A, 2B.
are formed respectively, thereby preventing rotation of the bobbin 5 and positioning it. However, with such a structure, there is no point in providing the convex portion 9 and the concave portion 10 unless the dimensional accuracy is sufficiently high, and in the case of a multi-channel magnetic head having multiple sets of cores, each bobbin 5 has approximately the same shape. Therefore, there was a risk that bobbin insertion errors would occur during the work process.

In view of the above points, the present invention has a simple structure by integrally forming a rotation prevention protrusion on one bobbin that comes into contact with the other bobbin when there are two sets of cores fitted with bobbins. The object of the present invention is to provide a two-channel magnetic head that can prevent the bobbin from rotating and position it, and can also facilitate the identification of the bobbin during the assembly process, thereby improving workability.

Embodiments of the two-channel magnetic head according to the present invention will be described below with reference to the drawings.

2 to 4, the second channel cores 20A and 20B are each approximately C-shaped, with a front gap 21 at the front end and a back gap 2 at the rear end.
It has 2. Similarly, the first channel core 23
A and 23B are also substantially C-shaped, and have a front gap at the front end and a back gap at the rear end. And the second channel core 20A, 2
A shield plate 24 for shielding between 0B and the first channel cores 23A, 23B and both cores are held by a pair of core holders 25A, 25B. The first channel bobbin 30 has flanges at both ends, and has a first convex portion 27 on the outer end surface of the flanges that comes into contact with the inner surfaces of the core holders 25A and 25B. A second protrusion 28 for preventing rotation is formed so as to extend in the outer circumferential direction of the collar so as to come into contact with the collar. And the first channel bobbin 30
A terminal 32 is integrally provided by press-fitting or molding. Also, the second channel bobbin 2
6 also has brim portions at both ends, and has a first convex portion 27 on the outer end surface of the brim portion, which abuts on the inner surface of the core holders 25A, 25B. And the second
A terminal 29 is also integrally provided on the channel bobbin 26 by press fitting or molding. Winding wires 31 are provided around the outer peripheries of these bobbins 30 and 26, respectively. These first and second channel bobbins 30, 26 are fitted into the back gap sides of the second channel cores 20A, 20B and first channel cores 23A, 23B, respectively, when the cores are matched. In this way, the core holders 25A, 2 hold each core in abutted state.
5B is inserted into the shield case 40, and further,
It is fixed by a screw 41 screwed into the side surface of the shield case 40. At this time, a shield block 42 is provided at the front opening of the case. Thereafter, resin is injected into the shield case 40, and the tape sliding surface on the front surface of the shield case 40 is polished to a predetermined degree. Incidentally, a through hole 43 is formed in the core holders 25A, 25B to improve resin inflow.

According to the configuration of the above embodiment, the second convex portion 28 for preventing rotation protruding in the outer peripheral direction of the collar portion of the first channel bobbin 30 is connected to the second channel bobbin 30.
6, the rotation of the bobbins 30 and 26 can be effectively prevented. Further, the axial wobbling of each bobbin 30, 26 can be prevented by the first convex portion 27 provided on each bobbin 30, 26 coming into contact with the inner surface of the core holder 25A, 25B. Further, since the first channel bobbin 30 has the second convex portion 28 in the direction of the outer circumference of the collar portion, and the second channel bobbin 26 does not have the second convex portion 28, it is extremely easy to distinguish between the two even if the bobbin is made smaller. , the workability is good, it is possible to prevent errors during assembly, and it is easy to arrange the bobbins during automatic assembly. Since the shape is suitable for reducing the size of the bobbin, the width of the magnetic head in the lateral direction (tape running direction) can be reduced.

In addition, the shield plate 24 and the shield case 40
is made of a magnetic material with high permeability such as permalloy, and each core is made of amorphous magnetic material or ferrite. Moreover, although the protrusion for preventing rotation is formed on the bobbin for the first channel, the protrusion for preventing rotation may be provided on the bobbin for the second channel.

As explained above, according to the present invention, in a configuration in which a first channel core having a first bobbin and a second channel core having a second bobbin are held by a core holder, the first and second bobbins are Since a rotation-preventing convex portion is formed on one of the bobbins to abut the other bobbin, the rotation of the bobbin is prevented, and the first and second bobbins can be easily identified during assembly, thereby improving assembly workability. It is possible to obtain a two-channel magnetic head capable of

[Brief explanation of drawings]

FIG. 1 is a plan sectional view showing an example of a conventional magnetic head, FIG. 2 is a side sectional view showing an embodiment of a two-channel magnetic head according to the present invention, FIG. 3 is a plan sectional view thereof, and FIG. It is a front view of the same. 20A, 20B...Second channel core, 23
A, 23B...First channel core, 24...Shield plate, 25A, 25B...Core holder, 26
...Bobbin for second channel, 27, 28... Convex portion, 31... Winding wire, 30... Bobbin for first channel, 40... Shield case.

Claims (1)

[Scope of utility model registration request] A core holder holds a first channel core provided with a first bobbin provided with a wire, a second channel core provided with a second bobbin provided with a wire wound, and a shield plate that shields between both cores. In the two-channel magnetic head, the first and second bobbins each integrally have a terminal, and the first and second bobbins each have a first convex portion that comes into contact with the inner surface of the core holder on the outer end surface of the collar portion of the first and second bobbins. A second convex portion for preventing rotation is formed on one of the first and second bobbins and extends in the outer circumferential direction of the collar portion of the bobbin. Channel magnetic head.