JPH0510727B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a magnetic head, and more specifically, it has an isolation member that isolates a magnetic shielding member provided between a plurality of magnetic cores and the magnetic core, and when the isolation member is used together with the magnetic cores during recording and reproduction. It relates to a magnetic head that slides on a magnetic recording medium. [Prior Art] Conventionally, in this type of magnetic head, when a magnetic recording medium such as a magnetic tape slides during recording and reproduction, uncured substances in the binder that fixes magnetic powder to the base material of the medium cause the head to slide. This causes a so-called stick-slip phenomenon due to repeated adhesion and peeling between the medium and the sliding surface of the head as the medium travels.This causes noise due to frequency modulation to be included in the recording/reproduction signal, as well as the sliding effect. It is known that so-called tape squeal occurs, in which the moving sound becomes directly audible. In this type of magnetic head, a structure is widely adopted in which a fixing material made of resin or the like is filled around the magnetic core to fix the magnetic core, and the fixing material also forms part of the head sliding surface. Since uncured binder substances and the like tend to adhere to the fixing material member on the sliding surface of the head, conventional measures have been taken to prevent tape squeal using only the fixing material. For example, there are methods such as cutting and removing the fixing material portion of the sliding surface so that it does not come into contact with the medium, spraying metal or the like onto the removed portion, or pasting a ceramic block on the portion. However, none of these methods has been sufficiently effective in preventing tape squeal. On the other hand, as a result of detailed experiments, it has been revealed that tape squeal occurs as follows. In other words, the binder of the magnetic tape first begins to adhere to the part of the fixing material adjacent to both ends of the magnetic core on the sliding surface of the head, where the contact pressure of the magnetic tape is low, and as the amount of adhesion increases, the binder adheres to the area between the magnetic core and the shielding member as described above. spread along the isolation member. Tape squeal occurs when the binder reaches the vicinity of the magnetic gap where the tape pressure is strongest from the end of the separating member. However, conventionally, phosphor bronze (C5101 according to JIS signal,
C5191, C5212, etc.) or nickel silver (C7351,
C7451, C7521, C7541, etc.) are used,
These materials are much easier to adhere to the tape binder than magnetic core materials such as permalloy, high-hardness permalloy, amorphous magnetic materials, sendust, and ferrite. That is, in the conventional structure, the isolation member is also a cause of tape squeal. [Objective] The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a magnetic head of the above-mentioned type that can effectively prevent so-called tape squeal with a structure that can be realized easily and inexpensively. It is an object. [Structure of the Invention] In order to achieve the above object, the present invention first uses Fe as a main component for the isolation member between the magnetic core and the magnetic shielding member in the magnetic head of the type described in the technical field section. Adopts a structure made of non-magnetic alloy. [Embodiments] Hereinafter, details of embodiments of the present invention will be described with reference to the attached drawings. FIGS. 1 and 2 are a front view of a magnetic tape sliding surface and an overall longitudinal sectional side view showing the structure of a magnetic head according to this embodiment. As shown in both figures, this magnetic head is constructed as a 4-channel head, and is designated by the symbols 1-1 to 1-.
Fit the four magnetic cores indicated by 4 into the case 5,
It has a structure in which a fixing material made of epoxy resin or the like, indicated by reference numeral 6, is filled into the case 5 and fixed. Each of the magnetic cores 1-1 to 1-4 is formed into a ring shape by abutting and joining a pair of core halves 1a and 1b made of a laminate of high-permeability magnetic thin plates such as permalloy. A magnetic gap 2 is formed on the abutting surface of the
A winding 9 through which a reproduction signal current flows is wound, and the ends of the winding 9 are connected to connection terminals 10, 10. The magnetic cores 1-1 to 1-4 are fixed with the magnetic gap 2 facing a sliding surface S on which the magnetic tape slides, that is, an opening 7 formed in the upper surface of the case 5. On the other hand, the shielding members indicated by numerals 4 and 4' in Figure 1 are the aforementioned shielding members that shield leakage magnetic flux between each magnetic core, and are made of a magnetic material such as permalloy into a thin plate shape as shown in the figure. Core 1-1 to 1-4
The sliding surface S is fixed with its upper end facing the opening 7 of the sliding surface S. And on both sides of each shielding member 4, 4', separating members 3, 3' are placed between magnetic cores 1-1 to 1-1.
is provided in between. The isolation members 3, 3' are for isolating each of the magnetic cores 1-1 to 1-4 and each shielding member 4, 4' as described above, and are formed into a thin plate shape as shown in the figure. is fixed facing the opening of the sliding surface S. In this embodiment, this isolation member 3,
3' is made of a non-magnetic alloy containing Fe as a main component. The preferred non-magnetic alloy is nickel chrome steel (as indicated by the JIS signal).
SNC236, SNC415, SNC631, SNC815,
SNC836, etc.); Nickel chromium molybdenum steel (SNCM220, SNCM240, SNCM415,
SNCM420, SNCM431, SNCM439,
SNCM447, SNCM616, SNCM625,
SNCM630, SNCM815, etc.); Chrome steel (SCr415,
SCr420, SCr430, SCr435, SCr440, SCr445
etc.) ; Chromium-molybdenum steel (SCM415,
SCM418, SCM420, SCM421, SCM430,
SCM432, SCM435, SCM440, SCM445,
SCM822, etc.); Manganese steel (SMn420, SMn433,
SMn438, SMn443, etc.); manganese/chromium steel (SMnC420, SMnC443, etc.); aluminum/chromium/molybdenum steel (SACM645, etc.). Also, a combination of a plurality of these types may be used. Alternatively, each of these may be added with other components. These non-magnetic alloys containing Fe as the main component were developed as a result of examining various materials for isolation members.
It has been confirmed that the taste-hardening substances in the binder of magnetic tape are extremely difficult to adhere to compared to other materials, and as mentioned above, the isolation member 3 is made of one or more of these alloys. ，
3', tape squeal can be extremely effectively prevented. As a modification of this embodiment, as shown in FIG. 3 in the above-described configuration, the fixing material 6 is not exposed to the portion of the sliding surface S facing the opening 7, and this portion is provided with the reference numeral 1.
A metal sprayed layer shown in 1 may be formed. (Instead, a ceramic member may be buried.) Alternatively, as shown in FIG. 4, the groove 12 may be formed by removing the fixing material 6 in the portion of the sliding surface S facing the opening 7 by cutting or the like. good. Even if these structures are adopted, it is expected that the tape squeal prevention effect will be equal to or greater than the cases shown in FIGS. 1 and 2. Next, a description will be given of a tape squeal test conducted on the magnetic head according to the above-described embodiment and its modified example, and a conventional magnetic head, and the results thereof. First, the isolation members 3 and 3' of the magnetic head sample according to this example were nickel-chromium steel (SNC415), nickel-chromium-molybdenum steel (SNCM220), chromium steel (SCr430), chromium-molybdenum steel (SCM420), manganese. Steel (SMn433),
We prepared seven types of thin plates with thicknesses of 0.2 mm3 and 0.1 mm3 from manganese-chromium steel (SMnC420) and aluminum-chromium-molybdenum steel (SACM645), respectively. In addition, two types of isolation members 3 and 3' of comparative samples of the conventional example were similarly prepared in the form of thin plates of 0.2 mm and 0.1 mm in thickness from nickel silver (C7451) and phosphor bronze (C5191), respectively. Next, using the above-mentioned nine types of isolation members in total, five samples of nine types of magnetic heads each having the three types of structures shown in FIGS. 1 to 4 were prepared for a total of 27 types. In addition, in these heads, magnetic cores 1-1 to
1-4 are core halves 1a and 1b formed from a laminate of three permalloy thin plates with a thickness of 0.2 mm;
It was formed by butting and joining. The shielding member 4 was formed from a permalloy thin plate having a thickness of 0.2 mm, and the shielding member 4' was formed from a permalloy thin plate having a thickness of 0.1 mm. The fixing material 6 used was a base material made of Epoquine resin containing 60% SiO ₂ fine powder. Furthermore, the metal sprayed layer 11 with the structure shown in Fig. 3 is made of Ni-Al.
Formed from metal spraying. Next, check the temperature for each of the prepared heads.
A cassette tape coated with γ-Fe ₂ O ₃ was slid at a speed of 4.75 cm/sec in an atmosphere of 55°C and 50% humidity, and the time from the start of sliding to the occurrence of tape squeal was measured. After finding the average of each individual,
The results shown in the table below were obtained.

[Table] As is clear from this table, the tape squeal occurrence time of the example sample is significantly longer than that of the comparative sample with the conventional structure, indicating that the structure of the example can provide an excellent tape squeal prevention effect. can be confirmed. The structure of the present invention relating to the isolation member described above is not limited to the four-channel head of the embodiment, but can also be applied to other magnetic heads such as a two-channel head as shown in FIG. 5, and similar effects can be obtained. Of course, this can be expected, and broadly speaking, it can be applied to all magnetic heads having isolation members similar to those described above. [Effects] As is clear from the above description, according to the present invention, in the magnetic head of the type described in the first technical field section, a non-magnetic head whose main component is the isolation member Fe that isolates the magnetic core and the magnetic shielding member. The extremely simple and easily realized structure of forming the tape from a magnetic alloy can extremely effectively prevent so-called tape squeal.

[Brief explanation of drawings]

FIG. 1 is a front view of a sliding surface showing the structure of a magnetic head according to an embodiment of the present invention, FIG. 2 is a vertical sectional side view of the head in FIG. 1, and FIGS. 3 and 4 show structures of modified examples. FIG. 5 is a front view of a sliding surface showing an example of another magnetic head to which the present invention can be applied. 1-1 to 1-4... Magnetic core, 2... Magnetic gap, 3, 3'... Separation member, 4, 4'... Shielding member, 5... Case, 6... Fixing material, 7... Opening, 8... Magnetic tape, 9... Winding wire, 10... Connection terminal, 11... Metal sprayed layer, 12... Groove.

Claims (1)

[Claims] 1. A magnetic head having an isolation member that isolates the magnetic shielding member provided between a plurality of magnetic cores and the magnetic core, and in which the isolation member slides on the magnetic recording medium together with the magnetic cores during recording and reproduction. Non-magnetic alloys containing Fe as the main component for isolation members include nickel-chromium steel, nickel-chromium-molybdenum steel, chrome steel, chromium-molybdenum steel, manganese steel, manganese-chromium steel, and aluminum-chromium-molybdenum steel. A magnetic head characterized by using at least one of the following.