JPS6327289Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a magnetic head used in a VTR or tape recorder, etc., and in particular, when the head section as an erasing head is attached to the case body, the front core is precisely positioned. Moreover, the present invention relates to a magnetic head having a structure that facilitates polishing of the tape running surface and facilitates mass production.

Conventionally, as shown in FIG. 1, this type of magnetic head 1 includes a front core 2, a bobbin 4 around which a coil 3 is wound, and a back core 5. After fitting and fixing, and fitting the dummy block 6 into the step part 7b from the front of the case body 7, the head part is installed in the fitting part 7a of the case body 7, and is fixed with adhesive and back mold 8. It was manufactured by polishing the tape running surface A. However, in order to position and attach the head part to the case body 7, the fitting part 7 of the case body 7 is required.
It was necessary to provide a stepped portion 7b in the case body 7 so that the dummy block 6 could be accurately fitted into the dummy block 6, and also to form a groove 6a in the dummy block 6 in which the front core 2 was accurately positioned.

For this reason, the machining accuracy of the stepped portion 7b of the case body 7 and the machining accuracy of the concave groove 6a of the dummy block 6 fixed to the front core 2 are issues, and even the slightest error can affect the performance of the magnetic head. This resulted in product variations and poor yields.

In addition, it is necessary to modify the stepped portion 7b of the case body 7 and the groove 6a of the dummy block 6, which requires too many man-hours, so that the structure cannot be mass-produced. Furthermore, the front core 2 of the head section
Since the dummy block 6 to which the tape is fixed has a concave groove 6a, the dummy block is thick by the thickness of the groove bottom, and the amount of dummy blocks is large, making the material uneconomical, and the tape running surface A must be polished after being fixed to the case body 7. When doing so, there were problems such as the amount of polishing required to reach the tip of the front core was large and the polishing time became long.

This idea was made in order to improve the above-mentioned drawbacks of the conventional magnetic head, and when attaching the head part of the magnetic head to the case body, it was possible to accurately position the front core, and it also required polishing of the tape running surface. The present invention provides a magnetic head having a structure that can be mass-produced in a short time.

Hereinafter, one embodiment of this invention will be explained in detail based on FIGS. 2 and 4. In the drawings, parts and parts corresponding to those of the conventional example will be described with the same reference numerals. Figures 2 and 4 are one embodiment of this invention, and Figure 2a is a sectional view taken along line A-A in Figure 2b;
FIG. 2b is a front view of the magnetic head. The dummy block 6 has a through hole 6b, and the tip of the front core 2 is inserted and fixed into the through hole 6b of the dummy block 6, and the dummy block 6 is attached to the stepped portion 7b of the fitting portion 7a of the case body 7. stick. A stopper 7c, which is a protrusion for positioning the rear end of the front core 2 of the head section, projects from the rear of the fitting section 7a of the case body 7. Above stopper 7
C is for accurate positioning by abutting the rear end of the front core 2 of the head fixed to the dummy block 6 within the fitting part 7a of the case body 7, and abuts against this stopper 7c. After the head portion is fixed by the back mold 8 in this state, the tape running surface A is polished. Therefore, the amount of polishing of the tape running surface A can be reduced.

3 and 5 are other reference examples based on this invention, in which a groove 7d for positioning the front core 2 of the head part is formed in the fitting part 7a of the case body 7, and the coil 3 is wound around the groove 7d. The rear end of the front core 2, into which the bobbin 4 is inserted, is positioned by fitting into the groove 7d.

As explained in detail above, the magnetic head according to this invention has a concave groove into which the front core fits into the conventional dummy block, in order to accurately position the front core that constitutes the head section that is incorporated into the case body. This is a through hole with a stopper protrusion provided at the rear of the fitting part of the head part of the case body, making it easy to assemble the head part, etc. that makes up the magnetic head, and also allows for accurate positioning. Therefore, product variations and yields are improved, and magnetic heads with stable performance can be supplied.

In addition, when polishing the tape running surface after incorporating the head part into the case body and performing a specified back mold, the thinner dummy block requires less material and processing costs, resulting in material savings. It has a structure that can be mass-produced because the polishing time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a conventional embodiment before polishing, FIG. , FIG. 2b is a front view of the magnetic head of the same embodiment,
FIG. 3 is a longitudinal sectional view of a case body showing a reference example of this invention, and FIGS. 4 and 5 are perspective views of the back of the case body of an embodiment and a reference example of this invention, respectively. 1...Magnetic head, 2...Front core, 3...
...Coil, 4...Bobbin, 5...Back core, 6
... Dummy block, 6a ... Concave groove, 6b ... Through hole, 7 ... Case body, 7a ... Fitting part, 7c
...stopper, 7d...groove.

Claims (1)

[Scope of utility model registration request] A magnetic head is constructed by combining a head part consisting of a front core, a bobbin with a coil wound thereon, a back core, etc., fixing the front core tip to a dummy block, and attaching the head part together with the dummy block to a case body, A magnetic head characterized in that the dummy block is provided with a through hole into which the front core is inserted, and a stopper for positioning the rear end of the front core of the head portion is provided protruding from the rear of the fitting portion of the case body. .