JPS6083208A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent a tape squeaking for a long period by adding an organic lubricant in a fixing material which is charged to fix a magnetic core in a shield case. CONSTITUTION:The organic lubricant is added in the fixing material 7, and then the organic lubricant in the fixing material 7 enters pores of a thermally-sprayed material layer 8 by capillarity at the opening part of the head surface of the shield case 6, i.e. where the fixing material 7 and the thermally-sprayed material layer 8 contact each other and is suppied to the outside surface of the thermally-sprayed material layer 8, i.e. magnetic recording medium sliding surface. Further, the organic lubricant is supplied from the fixing material 7 contacting the gap 3 of the head part where the magnetic core 1 extends to over the magnetic recording medium sliding surface. The organic lubricant is added in the fixing material 7 which is large in capacity, so the sliding friction between the magnetic recording medium sliding surface of a magnetic head and a magnetic tape is held small for a long period to prevent a tape squeaking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic head, and particularly to a magnetic head in which a magnetic core is fitted into a shield case, and the magnetic core is ! The present invention relates to a magnetic head having a moisture gap side facing the opening of the magnetic recording medium sliding surface of a shield case and having a magnetic rad Q filled and fixed with a fixing material so as to prevent so-called tape squeal phenomenon.

[Prior art]

So-called tape squeal occurs when the uncured substance in the binder of the magnetic tape softens due to temperature and rise when the 7iFf air head of this weight slides against an a-air recording medium such as a magnetic tape during recording and playback. This is a phenomenon in which the sliding friction between the magnetic tape and the magnetic recording medium sliding surface of the magnetic head increases, making it difficult for the magnetic tape to run smoothly and making the sliding sound audible.

In order to prevent such tape squeal, for example, Japanese Patent Application Laid-Open No. 49-43620 discloses that in this type of magnetic head, the fixing material made of synthetic resin used to fill and fix the magnetic core in the shield case is shielded. A structure is known in which the sliding surface of the case is not exposed at the sliding surface, but this portion is coated with a thermally sprayed material such as metal to form the sliding surface, thereby reducing the sliding friction of the sliding surface.

However, when such a structure is adopted, there are countless minute holes in the sliding surface of the magnetic head formed by thermal spraying, and when the magnetic tape slides, the magnetic powder and binder of the magnetic tape can penetrate these holes. Once it gets clogged, if you ignore it, magnetic powder and binder will adhere to the clogged area one after another.
Sliding friction increases and tape squeal occurs.

In order to eliminate these drawbacks of the above-mentioned structure, for example, Japanese Patent Application Laid-Open No. 52-86314 discloses a method of impregnating a lubricating substance into the above-mentioned thermal sprayed member to prevent an increase in sliding friction. Proposed.

However, even if such a method is adopted, the sprayed part of the sliding surface that is impregnated with lubricant is very thin, with a thickness of 17M1 or less, so the absolute amount of lubricant that can be impregnated is small, and it will not last for a long time. It is not possible to supply lubricant to the sliding surfaces over a long period of time, and tape squeal cannot be prevented for a long period of time.

Further, in such a structure, the magnetic head is formed by laminating thin plates of high permeability magnetic material in order to prevent eddy current loss. @
If scores are used, no tape squeal prevention effect can be expected from the beginning.

This is because the gap between the collapsed layers of the part facing the sliding surface of such a magnetic core is filled with voids or insulating synthetic resin (iη) because the magnetic tape slides. This is because magnetic powder or binder fills the gaps between the core laminations or adheres to the insulating synthetic resin portion, resulting in an increase in sliding friction.

〔the purpose〕

The present invention has been made in view of the above circumstances, and provides a magnetic head of the above type in which the magnetic core is made of a laminate of high permeability magnetic thin plates and the sliding surface is coated with a thermally sprayed material.
The object of the present invention is to provide a magnetic head that can prevent tape squeal over a long period of time.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. The figure shows the structure of an embodiment of the magnetic head according to the present invention.
In the figure, the reference numeral 1 indicates a magnetic core, which is constructed by abutting substantially U-shaped core halves 1a+1b, and a magnetic gap 2 is formed at the abutting surfaces of their heads. The core halves ia and ib are each made of a plurality of thin plates of high magnetic permeability magnetic material punched into a substantially U-shape.
It is made by laminating layers using an insulating synthetic resin adhesive.
The gap 3 between the thin plates of the head facing the sliding surface of the magnetic recording medium is formed as a void, or is filled with the insulating synthetic resin described in -h.

A coil 4 for electromagnetic conversion is wound around the base of the magnetic core 1, and this coil 4 is connected to a connection terminal 5.

Also, in Figure (C), there is a shield case (7J: i) that houses the magnetic core 1 and is magnetically routed to the outside, and the magnetic recording medium sliding portion on the head of the shield case. An opening (not shown) is formed in the head surface on the surface side.

Two magnetic cores 1 are fitted in this shield case 6, and the head surface with each magnetic gap 2 is connected to the magnetic recording medium on the head surface of the shield case 5 through the above-mentioned opening 1. A fixing material such as a synthetic resin, which faces the sliding surface, is injected and filled into the 7-ruby case 6 and is then hardened and fixed by the reference numeral 7.

The magnetic recording medium sliding surface is formed of a sprayed material layer 8 formed by spraying metal or the like onto the head surface of the shield case 6 except for the magnetic core 1 portion. This sprayed material layer 8 has numerous micropores, which are shown dotted in the figure. .

In the configuration described below, in the present invention, an organic lubricant is added to the fixing material 7. As this organic lubricant, any organic substance used as a lubricant in various fields can be used, but liquid lubricants, semi-solid greases, etc. are preferable. The organic lubricant may be classified from the viewpoint of production and may be petroleum-based, synthetic, fatty oil-based, or the like.

Among these organic lubricants, those that can be preferably used include, for example, metal soaps, fatty acid esters, higher alcohols, amines, silicone oils, fatty acid amides, olefin polymers, polyalkylene glycols, etc.・In addition to logenated hydrocarbon oils, various petroleum-based lubricants, hybrid lubricants, and lubricants mixed with predetermined thickeners can be mentioned.

Preferred organic lubricants include metal salts of higher fatty acids such as stearic acid, oleic acid, and palmitic acid (N, ], Ca, Mg, Ba, L).
i.

At, Zml ke + Cur 'P l-1+
The so-called metal soap C (RCO
esters of higher fatty acids such as methyl oleate and ethyl stearate [RCOOR]; higher alcohols such as oleyl alcohol and lauryl alcohol [ROH]; t-butylamine, aminopropionic acid, and chlorhexylamine nitrite Amines such as [
RNH2]; silicone oils such as methylpolysiloxane, phenylmethylsilicone compounds, and methylsilicone compounds; fatty acid amides CRCONI (2) such as oleic acid amide and stearic acid amide; and the like.

Such an organic lubricant is used by being added and mixed into the fixing material 6, and the appropriate mixing ratio is about 01% to 30φ by weight to 6 parts of the fixing material to 1 part of the synthetic resin.

The reason for this is that if the lubricant is not added at a rate of 0.1% or more, the effect of the lubricant, which will be described later, will not be achieved, but if it is added at a rate of 30% or more, the dimensional change of the fixing material 7 will become large, which will adversely affect the magnetic head's magnetic head characteristics. .

By adding the organic lubricant as described above to the fixing material 7, the opening part of the head surface of the shield case 60,
That is, the fixing material 7 and the sprayed material layer 8 penetrate into the micropores of the sprayed material layer 8 by capillary action, and are supplied to the outer surface of the sprayed material layer 8, that is, the sliding surface of the magnetic recording medium.

An organic lubricant is supplied to the gap 3 at the head of the magnetic recording medium sliding surface (C surface In some cases, the organic lubricant penetrates into the gap by capillary action, and if the gap 3 is filled with insulating synthetic resin, the organic lubricant transfers from the fixing material 7 to the insulating synthetic resin. do.

On the other hand, in the above structure, since the organic lubricant is added to the fixing material 7 which has a larger volume than the sprayed material layer 8, it is added in a larger amount than in the conventional structure in which only the sprayed material layer 8 is impregnated with the organic lubricant. Ru.

Therefore, as mentioned above (-7), the organic lubricant is supplied to the sliding surface of the magnetic recording medium including the head surface of the magnetic core 1 for a longer period of time than conventionally. The sliding friction between the magnetic recording medium sliding surface of the head and the magnetic tape is kept small, and tape squeal is prevented.

In the above magnetic head structure, if an organic lubricant is added in advance to the insulating synthetic resin constituting the laminate of the magnetic core 1, the effect of preventing tape squeal can be further enhanced. In that case, the addition ratio is the same as in the case of fixing material 7.

Next, we will discuss actual tape squealing performed on the magnetic head of the present invention having the above structure and the magnetic head having the conventional structure.
I will explain the comparative test and its results.

First, as the magnetic core of sample 1 of the magnetic head according to the present invention, four permalloy thin plates with a thickness of 0.15 m+ were stacked so that the gaps between the thin plates on the head surface were wide to form a half core. Then, we prepared 5 pieces that matched the core half-time through a gap.

In addition, for the magnetic core of Sample 2 according to the present invention, four of the same permalloy thin plates were laminated with epoxy resin interposed so that the entire gap between the thin plates was filled with epoxy resin, and they were bonded under heat and pressure to form a half core. I prepared 5 pieces that were matched through a gap.

Next, after attaching a coil to each of the magnetic cores of Samples 1 and 2, each was fitted into a shield case, and epoxy resin 1 was used as a fixing material, and a type of silicone oil was applied as an organic lubricant. Sample 1 was prepared by injecting and filling the shield case with 10 parts by weight of methyl polysiloxane, and then curing it to fix the magnetic core.
and 2 magnetic heads were obtained.

As sample 3 of a magnetic head with a conventional structure, we prepared five magnetic cores identical to those of sample 2 according to the present invention, each of which was fitted into a shield case, filled with epoxy resin only, and fixed to form a magnetic head. Formed.

For each of the five magnetic heads of Samples 1 and 2.3 obtained as described above, the magnetic recording medium sliding surface side including the head surface of the magnetic core was coated with nickel 96 weight and alumina 4 weight %, the sliding surface side was ground with a radius of 10R to expose the head surface of the magnetic core and give it a mirror finish.

Among these, for the magnetic head of Sample 3 having a conventional structure, the above-mentioned methylpolysiloxane was applied to the surface of the thermally sprayed portion and heated at 150° C. for 1 hour to impregnate it.

Each of the five magnetic heads of Samples 1, 2.3 thus obtained was tested at a speed of 4.
．． The tape was slid at 75 cisec, and the time from the start of tape running to the point at which tape squeal occurred was measured, and the average value for each sample was calculated, and the results shown in the table below were obtained.

As is clear from this table, samples 1 and 2 according to the present invention
Both of the tape squeal generation times of sample 3 with the conventional structure
This shows that the magnetic head according to the present invention can prevent tape squealing for a much longer period of time than the conventional magnetic head. The difference in the time at which tape squeal occurred between samples 1 and 2 of the present invention was very small, and even if the gap between the thin plates at the head of the laminate forming the magnetic core was a void, it was filled with the insulating synthetic resin. It can be seen that the effect of preventing tape squeal according to the present invention is the same even if the tape is used.

〔effect〕

As is clear from the above explanation, according to the present invention, 4iQ
Organic lubricant is added to the fixing material that fills and fixes the air core in the shield case, so the organic lubricant is applied to the sliding surface through the micropores of the sprayed material layer that forms the sliding surface of the magnetic recording medium of the magnetic head. is supplied for a long period of time, and as a result, the sliding friction between the magnetic recording medium sliding surface and between the magnetic recording media is maintained small for a long period of time, and the so-called tape squeal phenomenon is prevented.

[Brief explanation of the drawing]

The figure is a partially cutaway perspective view illustrating the structure of the magnetic head according to the present invention. 1.Magnetic core 1a+1b...Core half-closed 2...Magnetic gap 3...Gap 4...Coil 5...Connection terminal 6...Shield case 7...Fixing material 8 Sprayed material layer Patent applicant Canon Electronics Co., Ltd. Procedural Amendment (self-effective 1981 I B l 211 Mr. Commissioner of the Japan Patent Office 1, Indication of the case 1989 Patent Application No. 189354 2, Name of the invention Magnetic head 3, Person making the amendment Case/Relationships Patent application Person Name: Canon Electronics Co., Ltd. 4, Agent Telephone: 03 (268) 2481 (Drawing 6, contents of amendment The drawing will be amended as shown in the attached sheet. ＼ Close 3 ＼-10

Claims (1)

[Claims] 1) A magnetic core made of laminated high permeability magnetic thin plates is housed in a case, and the magnetic gap side of the core is ejected into an opening of the magnetic recording medium sliding surface of the case. In the magnetic head, the core is filled and fixed in a case with a fixing material, and the sliding surface except for the core portion is coated with a sprayed material, and an organic lubricant is added to the fixing material. Features a magnetic head. 2) As the organic lubricant, metal soap C(RCOO)n'M) consisting of metal salts of higher fatty acids such as stearic acid, oleic acid, and palmitic acid; esters of higher fatty acids such as methyl oleate and ethyl stearate; [:
RCOOR]; Higher alcohols such as oleyl alcohol and lauryl alcohol [RO■-1]; Amines such as t-butylamine, aminopropionic acid, and cyclohexylamine nitrite [RNH2]: Methylpholysiloxane, phenylmethyllicone compound, methyl silicone compounds/licone oils; oleic acid amide,
Fatty acid amides such as stearic acid amide [RCON11
The magnetic head according to claim 1, characterized in that at least one of the following is used.