JPS632976Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head suitable as an erasing head for erasing audio signals for VTRs.

As shown in FIG. 1, an audio signal erasing head 1 for a VTR is generally attached to the side of an audio signal recording/reproducing head 2 and used in an integrated state.

By the way, when molding the case of this type of magnetic head from ceramic or the like, it is important to know whether the molding machine to be used is vertical or horizontal, whether the molding method is injection or compression, etc. The split structure of case molding molds varies depending on the gate position and other factors.
For example, as shown in FIG. 2, there is a mold structure in which the mold split surfaces 5 are located on four surfaces including the mounting surface 4 of the case 3 of the magnetic head. In general, it is common for burrs to form on the mold surface as it is used during molding. Therefore, when the mold cut surface 5 is located on the mounting surface side of the case as shown in FIG. 2, the presence of burrs 6 on the mold cut surface as shown in FIG. When erasing head 1 is attached to
The positional relationship between the erase head 1 and the erase head 1 becomes poor.
In order to eliminate such inconveniences, such burrs are usually removed after the case is molded. but,
The deburring process itself had to be done using an automatic machine or by hand, which was a time-consuming process.

Furthermore, consideration must be given to the fact that as the mold is used, the cutting surface often becomes misaligned due to wear of the mold. For example, FIG. 4 or FIG. 5 shows a case where mold displacement occurs on the mold cutting surface 5. In these cases, the fourth
If the mold misalignment occurs as shown in the figure, there is no practical problem, but
If mold misalignment occurs as shown in FIG. 5, the same problem as burrs remaining on the mold cutting surface will occur.

In view of the above-mentioned points, the present invention has been developed by forming a step surface on the mounting surface side of the case that protrudes beyond the mold section surface located on the mounting surface, thereby preventing the adverse effects caused by burrs and mold displacement on the mold section surface. The object of the present invention is to provide a magnetic head that can always ensure accurate mounting positional relationships.

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

In FIG. 6, a tape sliding surface is located on the front surface of the case 10 of the erasing head, and this tape sliding surface is composed of a front core 11 and a dummy block 12. On the other hand, the mold splitting surface 13 is case 1
The mounting surface 14 of the case 10 has a stepped surface 16 that protrudes from the part where the mold splitting surface 13 is located by a dimension of a step 15. There is.

FIG. 7 shows a case where the erasing head 1A having a stepped surface 16 as shown in FIG. 6 is attached to the side surface of the recording/reproducing head 2. As a practical matter, the wall thickness of the case 10 is 0.5 to 0.65 mm, so the step 15 cannot be made very deep, but if it is at least 0.1 to 0.2 mm, the effect of the burr 17 generated on the mold split surface 13 can be removed. It is. However, it is natural that large burrs should be removed even if the structure is as in the embodiment. This is because after installation in a VTR or the like, these burrs must not fall off due to vibrations, shocks, etc. during transportation, and should not get between the tape and the head and cause damage when the tape is running.

According to the embodiment described above, it is possible to eliminate the adverse effects of burrs that occur on the mold surface, and it is possible to always maintain an accurate mounting positional relationship between the erasing head and the recording/reproducing head of the other party.

FIG. 8 shows another embodiment of the invention. In this case as well, a step 15A larger than the step due to the mold misalignment occurring on the mold splitting surface 13 is intentionally provided, and the mold splitting surface 1
By forming the step surface 16A that protrudes by the dimension of the step 15A with respect to the step 3, it is possible to eliminate the adverse effects caused by mold misalignment.

In each of the above embodiments, an erasing head for erasing an audio signal for a VTR was explained as an example, but the present invention also applies to a magnetic head that is attached and integrated with the side of a magnetic head of the other party. It is valid.

As explained above, according to the present invention, by forming a stepped surface on the mounting surface side of the case that protrudes more than the mold splitting surface located on the mounting surface, burrs and mold misalignment that occur on the mold splitting surface can be prevented. It is possible to obtain a magnetic head that can eliminate such adverse effects and always ensure accurate mounting positional relationships.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the erasing head attached to the side surface of the recording/playback head, Fig. 2 is a perspective view showing an example of the position of the mold cut surface in the magnetic head, and Fig. 3
The figure is a plan view showing the positional relationship between the erasing head and the recording/playback head when burrs occur on the mold cutting surface.
5 and 5 are respectively plan views showing a state in which mold misalignment has occurred on the mounting surface of the case of the erasing head due to the split surface of the mold, and FIG. 6 is a perspective view showing an embodiment of the magnetic head according to the present invention. 7 is a plan view showing the erasing head shown in the embodiment attached to the recording/reproducing head, and FIG. 8 is a plan view showing another embodiment of the present invention. 10...Case, 11...Front core, 12
...Dummy block, 13...Mold cutting surface, 14...
...Mounting surface, 15...Step, 16...Step surface, 17
……Bari.

Claims (1)

[Scope of utility model registration request] 1. A magnetic head characterized in that a step surface is formed on the mounting surface side of the case to protrude from a mold splitting surface located on the mounting surface.