JPH04137503U - magnetic head - Google Patents

Abstract

(57) [Summary] [Purpose] To uniformize the wear of the tape sliding surface so that there is less spacing loss and less deterioration of reproduction frequency characteristics even when used for a long time. [Structure] A non-magnetic plate 22 is placed on both sides of a magnetic plate 21.
Ratio X of the thickness Y of the non-magnetic material plates 22a and 22b to the thickness X of the shield plates 4, 5 and 6 in which the plates a and 22b are laminated:
Y is set to 0.55:0.17 (including the range of ±20%). In addition, the non-magnetic material is Fe20%-Cr20%
- Constructed of 60% Ni (including the range of ±20%).

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a magnetic head incorporating a shield plate. To explain in more detail, the present invention , multi-channel heads where there is insufficient space between the magnetic core and the shield plate, e.g. For example, a shield plate suitable for use in a 4-track 4-channel (4T4C) head, etc. Regarding improvements.

0002

[Conventional technology]

Multi-element (multi-chip) where sufficient spacing cannot be maintained between the magnetic core and the magnetic shield plate. For example, in a 4-track 4-channel head, the magnetic core In order to secure accommodation space for the coil to be wound on the The nearby magnetic shield plate must be made thinner. We also have magnetic core and shield plate A seal is used to prevent magnetic materials from coming into contact with each other and causing a magnetic short path. At least a non-magnetic part must be made in the part of the board that comes into contact with the core.

0003 Therefore, in the past, non-magnetic material was attached to the necessary parts of a long magnetic material by spot welding or laser welding. - After being fixed by welding etc., press it to the area corresponding to the sliding surface of the magnetic tape. Sandwich structure with only non-magnetic material and other parts made of magnetic material only. The shield plate near the coil of the magnetic core is formed to be thin (Japanese Patent Application Laid-Open No. No. 62-103812). In addition, cladding material made of non-magnetic material and magnetic material is rolled at predetermined intervals. The thick part and the thin part are continuously formed by pressing, and then the predetermined shape of the shield plate is formed by pressing. The shield plate is punched out to obtain a thin shield plate near the coil of the magnetic core (in practical use). No. 2-20805).

0004

[Problem that the idea aims to solve]

Until now, there has not been enough research into the relationship between the magnetic and non-magnetic materials of the shield plate, especially regarding the thickness. As a result, there are restrictions on the storage space that can be secured inside the shield case. It is press-molded to a thickness that satisfies approx. For this reason, both magnetic and non-magnetic materials are It is not possible to mold to a sufficient thickness, and the magnetic material becomes too thin to provide sufficient shielding effect. or the non-magnetic material is too thin, causing uneven wear on the tape sliding surface. This causes the problem that it deteriorates and cannot withstand long-term use.

[0005] This invention has uniform wear on the tape sliding surface, resulting in no spacing loss even after long-term use. The purpose of the present invention is to provide a magnetic head with less deterioration in playback frequency characteristics. .

[0006]

[Means to solve the problem]

In order to achieve this purpose, the magnetic head of the present invention has non-magnetic layers on both sides of a plate of magnetic material. A shield plate made of laminated steel plates is interposed between magnetic cores around which coils are wound. In a magnetic head assembled in a cold case, the thickness of the shield plate is The ratio X:Y of the thickness Y of the non-magnetic material portion is 0.55:0.17 within a range of ±20%. I am trying to set it to .

[0007] Further, the magnetic head of the present invention uses a Fe-Cr-Ni alloy as the non-magnetic material, and Each content ratio is Fe20%-Cr20%-Ni60%, each ±20 It has been adjusted to a range of %.

[0008]

[Effect]

When the thickness of the shield plate and the thickness of the non-magnetic material part are within the above range, sufficient magnetic This provides an air shielding effect and prevents uneven wear of the tape sliding surface. deer However, if the above range is exceeded, the characteristics (amount of wear) may deteriorate rapidly or the magnetic seal may deteriorate. detracts from the effect.

[0009]

【Example】

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention will be explained in detail based on the Example shown in drawing.

0010 FIG. 1 shows an example of a magnetic head implementing the present invention. The magnetic head shown in the figure is For example, magnetic recording and playback for auto-reverse of compact cassette tape recorders. This is a 4-track, 4-channel head used as a forward The magnetic head unit 2 for reverse and the magnetic head unit 3 for reverse are combined into one seal. It is housed in a case 1. Forward magnetic head unit 2 and reverse The magnetic head units 3 each constitute a magnetic head for the left channel. It has cores 7 and 8 and magnetic cores 9 and 10 that constitute a right channel magnetic head, One end of each magnetic core 7, 8, 9, 10 is exposed through the opening 23 of the shield case 1. These form magnetic pole faces 7a, 8a, 9a, and 10a. Each of these magnetic pole faces 7a, 8a, 9a and 10a are magnetic tape sliding contact surfaces 1 formed on the same surface and on which the magnetic tape slides. 1. Opposite the magnetic tape sliding surface 11 of each magnetic core 7, 8, 9, 10 A coil bobbin 1 is provided at the other end of each magnetic core 7, 8, 9, 10 extending in the direction. 2, 13, 14, 15 are attached to each coil bobbin 12, 13, 14, 15. A coil (not shown) is wound around it. Lead wires from each coil (not shown) are connected to the terminals 16, 17, 18, and 19 fixed to the terminal board 20, and are led to the outside. It's dark. In addition, as a magnetic core material, for example, PC17 (81Ni-2.7Nb -1.0W-0.7Ti-remaining Fe) and PC80 (81Ni-5.5Mo-remaining A permalloy material such as Fe) with an oxide film formed on the surface is preferred. Can be mentioned. Further, the shield case 1 is formed by, for example, the above-mentioned PC 80. ing.

[0011] Between the forward magnetic head unit 2 and the reverse magnetic head unit 3 That is, a center shield plate 4 is provided between the magnetic cores 9 and 8, and a center shield plate 4 is provided between the magnetic cores 9 and 8. A side seal is provided between each magnetic core 7 and 9 and 8 and 10 that make up the knits 2 and 3. board plates 5 and 6 are provided, respectively. These shield plates 4, 5, and 6 have one end It is arranged so as to constitute the same surface as the magnetic tape sliding contact surface 11, and the other end on the opposite side is a terminal. It extends close to the plate 20 and extends between adjacent magnetic cores 7 and 9, 8 and 9, and 8 and 10. and between the coils wound around these magnetic cores 7, 8, 9, and 10, respectively. It's shielded. Also, the magnetic tape sliding contact surface 11 of the shield plates 4, 5, 6 As shown in FIG. Plates 22a and 22b made of magnetic material (hereinafter referred to as non-magnetic plates) sandwich the central magnetic plate 21. The magnetic plate 21 and the non-magnetic plates 22a and 22b are arranged so as to sandwich each other in a German shape. The shield plate is configured as follows. Also, the other ends of the shield plates 4, 5, and 6 are also Magnetic plates 22a and 22b are provided on both sides to form a sandwich structure. this This reinforces the magnetic plate 21 and prevents it from deforming. For example, as a magnetic material, For example, it is preferable to use a permalloy material such as PC80. The surface of this magnetic material is oxidized. No film is formed. Further, as the non-magnetic plates 22a and 22b, for example, SU S304, FNC material (20Cr-20Fe-60Ni), copper alloy, nickel silver, Beryl Among them, 20Cr-20Fe-60Ni is used. It is preferable to use a Fe-Cr-Ni alloy in which each is adjusted within a range of ±20%. . In this case, the wear of the shield plates 4, 5, 6 is approximately the same as that of the magnetic cores 7, 8, 9, 10. It is possible to achieve a uniform wear condition by adjusting the amount. These non-magnetic plates 22a and 22b are In the case of the embodiment, one end portion of the shield plate 21 near the magnetic tape sliding contact surface 11 and It is provided only at the other end portion on the opposite side to the center portion of each shield plate 4, 5, 6, i.e. It is provided so that it is not formed near the coil of the magnetic core. magnetic tape printing The non-magnetic plates 22a and 22b near the contact surface 11 are arranged between adjacent magnetic cores 8 and 9. A predetermined interval is provided to prevent magnetic short circuits, and the position between each magnetic core 8 and 9 is It functions as a spacer that defines the interval.

0012 Here, the thickness of the non-magnetic plates 22a, 22b with respect to the thickness X of the shield plates 4, 5, 6 The ratio X:Y of length Y is set to be 0.55:0.17. This ratio It is permissible to change the ratio X:Y within a range of ±20%. In addition, center shield plate 4, even if the side shield plates 5 and 6 have the same ratio X:Y, the center seal Each size is approximately 1/2 the size of the board 4. Seats within this ratio When the thickness Y of the non-magnetic plates 22a, 22b in the magnetic plates 4, 5, 6 is set, The cores 7, 8, 9, 10 and the shield plates 4, 5, 6 wear evenly and can be used for a long time. This prevents spacing loss and deterioration of reproduction frequency characteristics.

[0013] The 4-track 4-channel head of the present invention (hereinafter referred to as ) and a 4-track 4-channel head set to a ratio outside the range. (hereinafter referred to as a comparative product). The experiment was conducted at a room temperature of 23°C and a humidity of 50°C. %, the magnetic tape was run for 1000 hours. Head after running for 1000 hours When measuring the tape sliding surface in the direction shown in Fig. 5(c), in the case of the product of this invention, As shown in 5(b), the core and shield plate are worn almost uniformly, but compared to The item had extremely uneven wear on the shield plate.

[0014] Next, an example of manufacturing the shield plates 4, 5, 6 and their incorporation into the shield case. I will explain about it. Figure 4 shows an overview of how shield plates 4, 5, and 6 are made from metal plates. A mental diagram is shown. Metal magnetic plate 21 and metal that are the materials of shield plates 4, 5, and 6 The manufactured non-magnetic plates 22a and 22b are supplied as long materials [see (a)], and rolled onto a rolling roll. The magnetic metal plate 21 is sandwiched between both sides of the magnetic metal plate 21 by the non-magnetic metal plates 22a and 22b. and crimping by cold rolling or hot rolling [see (b)]. and non-magnetic metal The plates 22a and 22b and the magnetic metal plate 21 are joined. After that, the laminated metal plates 3 1 is punched into a predetermined shape and size using a press, for example [see (c)]. Konoto The shape is, for example, as shown in FIG. 3(a). Also, finished dimensions For example, the magnetic plate 21 is 0.2 mm, and the non-magnetic plates 22a and 22b are 0.174 mm. The total thickness is 0.548 mm. That is, X:Y=0.548:0. It is 174. After that, an annealing treatment is performed. The cube obtained in this way Rudd material is generally called toplay cladding.

[0015] The shield plates 4, 5, 6 thus obtained are connected to magnetic cores 7, 8, 9, 10. Both are glued onto the frame to form a mount assembly. Incidentally, each magnetic core 7, 8, 9 and 10 are constructed by laminating five core materials with a thickness of 0.116 mm, for example. ing. The above-mentioned mount assembly is then sealed after the bobbin with the coil wound is installed. It is placed in a plastic case and fixed by filling it with synthetic resin, such as epoxy resin. It is. The head assembly obtained in this way is finished by polishing the tape sliding surface. It will be done.

[0016] The above-mentioned embodiment is an example of preferred implementation of the present invention, but is not limited thereto. Rather, various modifications can be made without departing from the gist of the present invention. example For example, the present invention partially press-forms a cladding material of magnetic and non-magnetic materials. It can also be applied to shield plates where the wall thickness near the coil is reduced by adding is possible. In this case, the non-magnetic plates 22a and 22b are completely connected to the magnetic plate 21. After stacking them with the same width dimension, create a strip of the specified size and shape that you want to take near the coil bobbin. Extraction that compresses the non-magnetic plates 22a, 22b and the magnetic plate 21 by the pace All you have to do is press it. The completed shield plates 4, 5, and 6 are shown in Figure 6. The shape and cross-sectional structure are as follows, but the thickness X of the shield plates 4, 5, 6 and the non-magnetic plate 2 The ratio of wall thickness Y of 2a and 22b is X:Y=0.55:0.17, within a range of ±20%. Set.

[0017]

[Effect of the idea]

As is clear from the above explanation, the present invention has non-magnetic plates on both sides of a magnetic plate. A shield plate made of laminated layers is interposed between magnetic cores around which coils are wound. In the magnetic head built into the base, the non-magnetic Set the ratio X:Y of the thickness Y of the steel part to 0.55:0.17 within a range of ±20%. As a result, the wear of the tape sliding surface of the magnetic head is uniform, and even after long periods of use, the tape sliding surface is uniformly worn. - Less sing loss and less deterioration of playback frequency characteristics.

[0018] In addition, in the present invention, the non-magnetic material is 20Fe-20Cr-60Ni (±20% (within the allowable range), the wear between the magnetic core and the shield plate will be more even. be unified. Incidentally, outside the range of wall thickness ratio mentioned above, wear becomes uneven and the characteristics suddenly change. It gets drastically worse.

[0019] In addition, when the present invention is used for top lay, it is possible to Compared to the irregular-shaped rolling of This makes it an ideal shield plate for magnetic heads.

[Brief explanation of drawings]

FIG. 1 is a central vertical cross-sectional view showing an example of the structure of a magnetic head.

FIG. 2 is a front view of the magnetic head.

FIG. 3 is a diagram showing an example of a shield plate, in which (a) is a perspective view, and (b) is a view taken along the line III-III.

[Figure 4] The manufacturing process of the shield plate (a), (b),
It is a schematic explanatory view divided into (c) and shown.

FIG. 5 is an explanatory diagram showing a comparison of the wear patterns of the product (b) of the present invention and the comparative product (a). (c) is an explanatory diagram showing the measurement direction.

FIG. 6 is a drawing showing another embodiment of the shield plate according to the present invention, in which (a) is a perspective view, and (b) is a view taken along the line VI-VI.

[Explanation of symbols]

4,5,6 Shield plate 21 Magnetic plate 22a, 22b non-magnetic plate X Shield plate thickness Y Thickness of non-magnetic plate

Claims (2)

[Scope of utility model registration request] 1. A magnetic head in which a shield plate, in which non-magnetic plates are laminated on both sides of a magnetic plate, is interposed between magnetic cores around which a coil is wound, and incorporated into a shield case,
A magnetic head characterized in that a ratio X:Y of the thickness Y of the non-magnetic material portion to the thickness X of the shield plate is set to 0.55:0.17 within a range of ±20%. 2. The nonmagnetic material is a Fe-Cr-Ni alloy, and the content ratio of each is Fe20%-Cr20.
%-Ni60%, each of which is adjusted within a range of ±20%.