JPS6259363B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an erasing head for a VTR or a cassette deck.

[Prior Art] Conventionally, as shown in FIGS. 1 and 2, the erasing head is manufactured by inserting the head portion 2 into the fitting portion 3a of the main body 3 and fixing it with adhesive, followed by back molding and tape sliding surface. It is made by polishing 3b.
That is, the head section 2 of the erasing head 1 has a front core 2b and a back core 2c fixed to the coil 2a by adhesive, and has a ferrite section or a ferrite-containing heat source above and below the front core 2b located on the tape sliding surface 3b. In the former case, the plastic resin part 2e is made of glass with adhesive 2d, and in the latter case,
It is integrally constructed by fixing a resin material as an adhesive 2d, and after inserting this head part 2 into the fitting part 3a of the main body 3 from the direction of the tape sliding surface 3b and adhering it, the tape sliding The erasing head 1 was manufactured by polishing the surface 3b into an arc shape.

[Problems to be solved by the invention]

Therefore, the head section 2 of the erasing head 1 requires a large number of parts such as a front core, a back core, a coil, a ferrite section or a thermoplastic resin section containing ferrite, and a bonding process for the ferrite section or thermoplastic resin section containing ferrite. It is not suitable for mass production because it requires a process of gluing the head part 2 to the main body 3, and there are many work steps from manufacturing each part to assembly process including the gluing process mentioned above. There is a lot of variation in the final erase head product, so when the erase head is attached to a recording/playback device and used, there is a positioning error (azimuth loss) of the erase head relative to the tape recording/playback track, etc.
There were disadvantages in that the erasing efficiency decreased, the S/N ratio deteriorated to several decibels or less, and the manufacturing yield also deteriorated. Furthermore, when machining the fitting part 3a of the main body 3 into which the integrated head part 2 is inserted, grinding fluid remains inside, which tends to cause poor insulation.

Further, even if the head portion 2 is inserted into the fitting portion 3a of the main body 3 using a jig and fixed, it is necessary to back-mold the gap inside the fitting portion 3a. Furthermore, when the head portion 2 of the erasing head 1 is made of a resin containing ferrite, the resin is generally a thermoplastic resin such as polyacetal, which has poor thermal shock resistance and abrasion resistance, and is prone to wear during tape running. This has disadvantages such as the inability to maintain stable tape running, and the disadvantage that the life of the erasing head is shortened. Therefore, the present invention solves and eliminates the above-mentioned problems, drawbacks, and disadvantages by reducing the number of parts, manufacturing processes, and V.
It is an object of the present invention to provide a method for manufacturing an erase head for a TR or a cassette deck.

[Means of solution and action]

That is, according to the present invention, there is a method for manufacturing an erasing head for a VTR or cassette deck, which comprises a head section that includes a front core, a back core coupled to the front core, and a coil wound around the front core, and is fitted and housed in the main body section. A fitting recess for accommodating the head is formed in the main body, and a guide groove for positioning the front core of the head is formed in advance in the fitting recess, and the head is positioned and housed in the main body. Provided is a method for manufacturing an erasing head in which the periphery of the tape sliding surface of the eraser head is filled with a resin material containing an inorganic filler for molding, and then polished to form an arcuate tape sliding surface. The number of component parts of the head section is reduced, and the number of manufacturing steps is reduced by eliminating the bonding process, and the positioning accuracy of the head section relative to the main body section can be maintained constant and stabilized by the above-mentioned guide groove. This can contribute to mass production. Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

〔Example〕

3 and 4 show an erasing head manufactured by the method of the present invention, and in the figures, parts and parts corresponding to those of the conventional example are given the same reference numerals and will be explained.

The head part 2 constituting the erasing head 1 has a front core 2b and a back core 2c fixed to a coil 2a with adhesive. The front core 2b is inserted and housed in the section 3a, and the periphery of the front core 2b on the side of the tape sliding contact surface 3b is filled with a resin 4 containing an inorganic filler, and then the surface is polished into an arc shape. Therefore, unlike the conventional example, the head part 2 does not require the adhesive 2d made of glass or resin that adheres and clamps the front core 2b, and the parts of the ferrite part or the resin part 2e. By reducing the number of parts, manufacturing can be simplified and costs can be reduced.

The resin 4 containing an inorganic filler filled in the tape sliding surface 3b of the erasing head 1 is a thermosetting resin containing an inorganic filler made of fine powder such as alumina, and has excellent wear resistance. It is an epoxy resin that shows

The concave fitting part 3a of the main body 3 into which the head part 2 of the erasing head 1 is inserted has a guide groove 3c so that the front core 2b of the head part 2 is accurately positioned with respect to the tape sliding surface 3b. is recessed and formed in advance during the molding process of the main body 3, and the entrance portion of the guide groove 3c of this fitting portion 3a is chamfered 3.
d has been applied. In other words, in the assembly process of inserting and fitting the head portion 2 into the main body 3, the work of inserting the front core 2b into the guide groove 3c is facilitated, and at the same time, the chamfering reliably removes molding burrs, making positioning easier. It is possible to maintain constant accuracy and stability. It is also possible to reliably control the position when filling the resin 4 after inserting the head portion 2, and the relative positioning accuracy between the main body 3 and the head portion 2 is improved.

〔Effect of the invention〕

As is clear from the above explanation, according to the manufacturing method of the erasing head according to the present invention, the number of component parts of the erasing head is reduced and the number of bonding steps is reduced, thereby reducing cost and reducing and simplifying the assembly work process. In addition, the guide groove integrally formed in the main body allows the front core of the head to be assembled with the main body in an accurate and constant position during the manufacturing process of the erase head, which facilitates mass production of the product. In doing so, it is possible to stabilize the product accuracy, in other words, mass production is possible, and to maintain accurate positional relationships, if the main body is correctly attached to the recording/playback device, the core can be attached to the tape. As a result, the tape track and the front core can be accurately positioned and the erasing efficiency can be maintained at a high level. In addition, the manufacturing method in which the head part is fixed inside the main body using a thermosetting resin causes the resin and the filler mixed therein to solidify, causing the filler to fall off during sliding contact with the tape and clogging the head gap. It also has the effect of alleviating concerns.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an erasing head before assembly showing a conventional embodiment, FIG. 2 is a front perspective view showing a conventional erasing head, and FIG. 3 is a front perspective view of an erasing head according to an embodiment of the present invention before assembly. FIG. 4 is a front perspective view of an erasing head according to the present invention. 1... Erasing head, 2... Head section, 2a...
... Coil, 2b ... Front core, 2c ... Back core, 3 ... Main body, 3a ... Fitting part, 3b ...
Tape sliding contact surface, 3c...guide groove, 3d...chamfer, 4...resin.

Claims (1)

[Scope of Claims] 1. A method for manufacturing an erasing head for a VTR or cassette deck, which comprises a front core, a back core connected to the front core, and a head section equipped with a coil wound around the front core, which is fitted into a main body section and housed therein. A fitting recess for accommodating the head is formed in the main body, and a guide groove for positioning the front core of the head is formed in advance in the fitting recess, and the head is positioned and housed in the main body. Manufacturing of an erasing head characterized in that the periphery of the tape sliding surface is filled with a resin material containing an inorganic filler for molding, and then polished to form an arcuate tape sliding surface. Method. 2. A chamfer is formed in advance at the insertion entrance of the head in the front core positioning guide groove formed in the fitting recess of the main body, so that the head can be smoothly fitted into the main body. A method for manufacturing an erasing head according to claim 1.