JPH10275437A - Magnetic transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floating type magnetic transducer having little varied lift that is susceptible to an airflow and hence difficulty to shift a position of a magnetic gap. SOLUTION: In the magnetic transducer 10 equipped with rail parts 1, 2 and 3 having planar rail surfaces for forming air sliding films between themselves and the surface of a magnetic medium in both side parts respectively and groove parts formed between these rail parts, ratios of width(w) to height(h) from the rail surfaces 1b, 2b and 3b of the magnetic transducer as observed from the upstream side of an airflow into the magnetic transducer 10 are set to suppressing values of varied lift worked on the magnetic transducer 10 due to the airflow, i.e., 3.8 to 6.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic transducer,
In particular, the present invention relates to a magnetic transducer used for a magnetic head of a magnetic disk device. 2. Description of the Related Art In magnetic recording, a magnetic gap of a magnetic transducer is brought as close as possible to a magnetic storage medium (hereinafter, simply referred to as a magnetic medium) such as a magnetic disk, while a direct connection between the magnetic medium and the magnetic transducer is made possible. In order to avoid contact, an air levitation type magnetic transducer using an air bearing as described in Japanese Patent Application Laid-Open No. 49-121514 has been developed. Such a conventional magnetic transducer will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a perspective view of a conventional magnetic transducer, and FIG. 3 is an explanatory view of a flow of air around the conventional magnetic transducer as viewed from a direction perpendicular to a magnetic medium. The magnetic transducer shown in FIG. 2 is a perspective view seen from the magnetic medium side, and the magnetic medium (not shown) approaches the magnetic transducer from the lower left of the figure and leaves at the upper right. On the surface of the magnetic transducer 9 facing the surface of the magnetic medium, there are formed three rails 1, 2, 3 extending in parallel at intervals in the direction of relative movement with the magnetic medium. These rails l,
Each of the tapes 2 and 3 has tapered portions 1a, 2a and 3a on the near side of the magnetic medium, and has rail surfaces 1b, 2b and 3b behind the tapered portions 1a, 2b and 3b to provide an air sliding surface with the magnetic medium surface. To form. Central rail part 2
A magnetic core 4 and a magnetic gap 5 are provided at the rear of the head. The magnetic gap 5 must be accurately held on a predetermined storage track on a magnetic medium. Normally, such a magnetic transducer 9 is provided on the access mechanism by a support means (not shown) including a gimbal and a spring member. This is performed by a known means in which a gimbal is bonded to the bottom surface 6a 'of a groove 61 provided substantially at the center in the longitudinal direction on the back side of the container 9. In an operating state in which the magnetic transducer floats with a small distance from the surface of the magnetic medium, the magnetic transducer is exposed to the flow of air from the direction of relative movement. When the flow of air around the magnetic transducer at this time is viewed from the direction perpendicular to the surface of the magnetic medium, as shown in FIG. 3, the flows 11, 12 that separate at the front edges 7, 8 on both side surfaces of the magnetic transducer. The so-called Karman vortex street 13 is generated behind the right and left peeling alternately. [0004] When such a Karman vortex street 13 is generated, as is well known, a magnetic force is applied to the magnetic transducer 9 in a direction perpendicular to the flow of air, the force of which changes in size and direction over time, that is, a fluctuating lift. Works. As described above, since the magnetic transducer 9 shown in FIG. 2 is adhered to the supporting means at substantially the center thereof, the magnetic transducer 9 is subjected to the above-mentioned fluctuating lift. Rotational vibration (oscillating motion) occurs around the support means bonding portion.
Further, as described above, since the magnetic gap 5 is provided at the downstream end of the magnetic transducer 9, there is a problem that the rocking motion causes a displacement of a magnetic medium, for example, a magnetic disk from a recording track. There was. SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem of the prior art, and provides a floating type magnetic transducer which has a small fluctuation lift received from an air flow, and therefore, a magnetic gap is hardly displaced. To
It is selfish. [0006] As a means for solving the above-mentioned problems, the present invention provides at least a flat rail surface for forming an air sliding film with a surface of a magnetic medium. A rail portion on both sides and formed between the rail portions,
A bottom surface being a plane parallel to the rail surface and having a groove portion continuous from an inflow end to an outflow end of the airflow, wherein the magnetic conversion as viewed from the upstream side of the airflow to the magnetic converter is provided. The ratio of the width w to the height h of the vessel from the rail surface is set to a value that suppresses the fluctuating lift acting on the magnetic transducer by the air flow, that is, from 3.8 to 6. Here, the concept of developing the present invention will be described with reference to FIG. 4 to FIG. FIG. 4 is a front view of the magnetic transducer of FIG. 2, FIG. 5 is a frequency distribution diagram of the variable lift, and FIG. 6 is a diagram showing the amplitude of the peak frequency component of the variable lift and the cross-sectional shape of the magnetic converter. FIG. 4th
The figure is a front view of the conventional magnetic transducer 9 viewed from the upstream side of the air flow. In other words, the magnetic transducer 9 is viewed from the direction in which the magnetic medium approaches the magnetic transducer 9. This corresponds to a diagram showing a projected shape of the converter. Assuming that the height perpendicular to the magnetic medium 20 of the conventional magnetic transducer 9 shown in FIG. 4 is h and the width parallel to the magnetic medium 20 is w, w / h is 2.8. The present inventors have proposed a magnetic transducer 9 held at a small distance from the magnetic disk of the magnetic medium 20.
Was measured and the frequency was analyzed. As a result, the results shown in FIG. 5 were obtained. FIG.
The horizontal axis shows the frequency and the vertical axis shows the fluctuating lift. As is clear from this figure, it was found that the fluctuating lift fluctuated at a specific frequency. This is different from the occurrence of the Karman vortex street shown in FIG. [0007] Then, the present inventors next measured the peak value of the variable lift using w / h as a parameter, and obtained the results shown in FIG. In FIG. 6, the horizontal axis represents w / h representing the cross-sectional shape of the magnetic transducer, and the vertical axis represents the amplitude of the beak frequency component of the variable lift as an index, as shown in FIG. In addition, it was found that when w / h is 3.8, the amplitude becomes about l / 2 when w / h is small, and when w / h exceeds 4, the fluctuation of the specific frequency is not observed. Therefore, if w / h in the projected shape of the relative motion direction formed by the magnetic transducer with the magnetic medium is set to 3.8 or more,
It was found that the displacement of the magnetic gap due to the fluctuating lift could be reduced. To obtain a better effect, w /
It is preferable to set h to 4 or more. Next, FIG. 7 is an explanatory view showing the flow of air around the magnetic transducer of the present invention.
In this case, the flow of air at the time of (1) is shown as a vortex shape in comparison with FIG. As shown in FIG. 7, from the leading edges 7 and 8 on both sides of the magnetic transducer, a vortex street 14 in which the flow is symmetrical in the left and right direction (up and down in the figure) is generated, so that the fluctuating lift is reduced. It is considered something. Symmetric vortex street 1
The reason for the occurrence of 4 is that the distance between the left and right front edges 7 and 8 of the magnetic transducer is large, and because of this, between the rails 1 and 2 and between the rails 2 and 3, the upstream and downstream in the relative movement direction. Separation from both leading edges 7 and 8 due to the strong influence of the flow flowing into the wake from the flow of air through the groove formed in the air flow and the flow of air passing behind the magnetic transducer It is considered that the mutual interference weakened. An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a perspective view of a magnetic transducer according to one embodiment of the present invention, in which the same reference numerals as in FIG. 2 denote the same parts as in the conventional example, and a description thereof will be omitted. The magnetic transducer 10 shown in FIG. 1 is formed with three rails 1, 2, 3 extending in parallel with each other at intervals in the direction of relative movement with the magnetic medium, as in FIG. The air sliding surface is formed between the rail surfaces lb, 2b, and 3b and the surface of the magnetic medium. The magnetic transducer 10 has a thin overall shape, and is used when the magnetic medium 20 (see FIG. 4) views the magnetic transducer 10 from a direction approaching the magnetic transducer 10. The ratio w / h of the width w parallel to the surface of the magnetic medium 20 to the height h perpendicular to the surface of the magnetic medium 20 in the projected shape of the container is formed to be 3.8. Since the overall shape is thin, the groove 6 for attaching the support means connected to the access mechanism is shallow, but the gimbal is adhered to the bottom surface 6a, and the function of the support is different from that of the related art. There is no. Accordingly, the magnetic core 4 and the magnetic gap 5 provided behind the central rail portion 2 are connected to the magnetic medium 20,
For example, it is accurately held on a storage track of a magnetic disk. In an operating state in which the magnetic transducer 10 floats with a small distance from the surface of the magnetic medium 20, the magnetic transducer 10 is exposed to the flow of air from the direction of relative motion. As described earlier with reference to FIG. 7, the vortex streets 14 symmetrical to the left and right (up and down in FIG. 7) of the air flow are generated from the front edges 7 and 8 on both sides of the magnetic transducer 10.
The fluctuating lift acting on the magnetic transducer 10 is suppressed to a small value. Therefore, according to the magnetic transducer 10 of the present embodiment,
The oscillating motion of the magnetic core 4 and the magnetic gap 5 is suppressed,
The positional deviation of the recording track of the magnetic medium, for example, the magnetic disk from the recording track is reduced, and the effect of reducing the positioning error to less than 1/2 of the conventional one can be obtained. It should be noted that the present invention is not limited to the wound type magnetic transducer shown here, but can be applied to a thin film type magnetic transducer. Further, it goes without saying that the present invention is not limited to the presence or absence of the groove 6a 'for bonding the support spring, and can be applied. As described above, according to the present invention, there is provided a floating type magnetic transducer which has a small fluctuation lift received from the flow of air, and is therefore less likely to cause a magnetic gap displacement. can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic transducer according to one embodiment of the present invention. FIG. 2 is a perspective view of a conventional magnetic transducer. FIG. 3 is a diagram illustrating the flow of air around a conventional magnetic transducer. FIG. 4 is a projection view of a conventional magnetic transducer viewed from an upstream side of an air flow. FIG. 5 is a diagram showing a frequency distribution of a variable lift. FIG. 6 is a diagram showing the relationship between the amplitude of the peak local wave number component of the variable lift and the cross-sectional shape of the magnetic transducer. FIG. 7 is a diagram illustrating the flow of air around the magnetic transducer according to the present invention. [Description of Signs] 1, 2, 3 ... rail section, lb, 2b, 3b ... rail surface, 4 ... magnetic core, 5 ... magnetic gap, 1
0: magnetic transducer.

Claims (1)

[Claims] 1. A rail portion having a flat rail surface on at least both sides forming an air sliding film between the surface of the magnetic medium,
A groove formed between the rails and having a bottom surface that is a plane parallel to the rail surface and that is continuous from an inflow end to an outflow end of the airflow. The ratio of the width w to the height h of the magnetic transducer from the rail surface as viewed from the upstream side is set to a value that suppresses the fluctuating lift acting on the magnetic transducer by the airflow, that is, from 3.8 to 6. A magnetic transducer, characterized in that: