JPH023135A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the durability of a floppy disk and a magnetic head by making the radius of curvature between the required edges of the slidable contacting face of a core holding body specific relation. CONSTITUTION:A radius of curvature R1 of an edge which is at right angles to a traveling direction at the inflow edge side of the disk traveling direction of a flat shaped slidable contacting face 4 providing an air layer 5 of a core holding body 4 which contacts slidably with a floppy disk is more than five times as long as a radius of curvature R2 of the same curved face processing of the inflow edge side. By the constitution suppressing the radius R2 to a minimum, the durability of the floppy disk and a magnetic head is improved and the forming of the magnetic head is made easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head used in a magnetic recording/reproducing device, and more particularly to an improvement in the shape of the sliding surface of a 6R magnetic head.

[Conventional technology]

2. Description of the Related Art A flexible magnetic recording medium (hereinafter referred to as a floppy disk) is magnetically recorded and reproduced while being held between a magnetic head device consisting of a pair of opposing magnetic heads. In some cases, one side is a magnetic head and the other side is a pad, but since they can be handled in the same way, the case of a pair of opposing magnetic heads will be described below.

FIG. 5 shows a schematic perspective view of one of the conventional magnetic heads. The other opposing magnetic head also has the same structure. The magnetic head 1 consists of a core holder 2 made of barium titanate or calcium titanate, a recording/reproducing core 3 embedded in the core holder 2, and a recording/reproducing coil (not shown) wound around the recording/reproducing core. ing. The core holder 2 forms a flat sliding surface 4 for stable contact with the floppy disk, and the length of this surface in the sliding direction (arrow D) is about 5 mm. Air grooves 5 are provided on the sliding surface in parallel to the direction of arrow D, so that air that is drawn in as the floppy disk runs is released.

Due to this air groove 5, the sliding surface 4 is divided into two parts 4a +
They are separated by 4 hours. The two sides (EF, GH in Figure 5), which are perpendicular to the running direction of the floppy disk at the inlet and outlet ends of the sliding surface, are curved so that the sharp corners do not damage the floppy disk. However, as mentioned above, the material is very hard, such as barium titanate, and processing takes time, so the radius of curvature of the curved surface is usually about 0.2 mm at most. Now, this magnetic head l has a gimbal spring 6 as shown in FIG.
The sliding surface 4 is attached upward to the inner frame 6a. The gimbal spring 6 fixes the outer frame 6c and holds the magnetic head 1, and is attached so that its sliding surface 4 is in sliding contact with the floppy disk. Here, the inner frame 6a is connected to the central frame 6b, and the central frame 6b is connected to the outer frame 6c by connecting shafts 6d and 6e, respectively, and the sliding surface 4 of the magnetic head 1 is connected to the connecting shaft 6d.
, 6e as rotational axes, and are formed so as to swing back and forth and left and right and maintain contact with the floppy disk surface. FIG. 7 is an explanatory diagram of the principle of the magnetic head part when the floppy disk is running. When the floppy disk runs in the direction of the arrow, the upper and lower magnetic heads 1 are caused to flow into the floppy disk due to friction caused by sliding contact with the surface of the floppy disk 7. It shows that it is tilted to the side. Due to this inclination, the sliding surface 4 of the magnetic head 1 presses against the floppy disk at the floppy disk inflow side end. As mentioned above, this inflow side end is composed of a curved surface with a radius of curvature of about 0.2+wm, but because the radius of curvature is small, the contact angle between the tip of the magnetic head and the floppy disk at the contact point with the floppy disk is small. As a result, the inlet end of the magnetic head was subject to severe wear, and the floppy disk was also severely damaged, causing a loss of durability.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a magnetic head that maintains good contact with a floppy disk, has excellent durability, and is inexpensive.

[Means for solving problems]

In order to achieve this object, the present invention increases the radius of curvature of the sliding contact surface of the magnetic head at the end on the floppy disk inlet side.
By reducing the contact angle between the tip of the magnetic head and the floppy disk while the floppy disk is running, the sliding resistance between the magnetic head and the floppy disk is reduced and durability is improved. Figures 8 and 9 are explanatory diagrams of the contact angle between the tip of the magnetic head and the floppy disk, and show the case where the magnetic head is tilted in the inflow direction at an angle α due to sliding resistance due to running in the D direction of the floppy disk. . FIG. 8 shows an example in which the radius of curvature R+ of the finished curved surface of the inflow end is as large as about 111-, and FIG. 9 shows an example in which the radius of curvature R2 is as small as about 0.2-. As is clear from the figure, when the radius of curvature at the tip of the magnetic head is large, the contact angle θ is small, and the example in FIG.
Compared to the example shown in the figure, it is less susceptible to wear due to sliding contact. However, Figure 8.9 is exaggerated for the sake of explanation, and according to actual research on floppy disk drive devices, the magnetic head tilt angle α is 0.4° to 0.6'', and at this time, the tip of the magnetic head The number of beds that push the floppy disk surface is 0.
, about 02 mm to 0.04 mm. Under the above conditions obtained through actual measurements, the relationship between the contact angle and the radius of curvature of the tip of the magnetic head is shown in FIG. 10, using the head inclination angle α as a parameter. Experiments have shown that if the contact angle θ is less than 20', there is almost no wear. This is true even when the magnetic head tilt angle α is the maximum 0.6', the graph P in Figure 10
It can be seen from the points that this can be achieved if the radius of curvature is 1.0 mm or more.

〔Example〕

FIG. 1 shows an embodiment of a magnetic head according to the present invention. Fig. 1 is a schematic perspective view of one of a pair of magnetic heads facing each other, and corresponds to the conventional example shown in Fig. 5, and the same parts are given the same reference numerals. . The only difference from FIG. 5 is that the radius of curvature of the curved surface at the tip of the corner at the end of the floppy disk inlet side of the sliding surfaces 4a and 4b is increased, and the rest is the same as the conventional example shown in FIG. Aworu. Figure 1: AA cross-sectional view The total length of the magnetic hesode shown in Figure 2 is generally! ! - About 6ml11, the inflow side end is R+
” 1mm wl = 0.6mm dl
= Q, 2mH, while the lump exit end is R2 = 0.2mm WZ = 0.2mn + d
z = 0.2mm. In this way, the radius of curvature at the inlet end is made large, and the radius of curvature at the outflow end is kept at the minimum as in the conventional method, thereby preventing an unnecessary increase in machining time. Figure 3 shows another embodiment of the AA cross-sectional view in Figure 1, in which the tip of the corner at the inflow side end is polished straight and obliquely, and all other dimensions are as shown in Figure 2. is the same as In other words, FIG. 3 shows the length of R in FIG. 2 made infinite.

FIG. 4 is a diagram illustrating the principle of the magnetic head portion in a floppy disk running state when the magnetic head according to the present invention is used, and corresponds to FIG. 7 of the conventional example. This shows that by increasing the radius of curvature of the curved surface at the inflow side end, the contact angle between the magnetic head and the floppy disk is reduced when the magnetic head is tilted toward the inflow side. This reduces the sliding resistance between the magnetic head and the floppy disk, increasing the durability of both the magnetic head and the floppy disk.On the other hand, the processing time is reduced due to the extremely hard materials such as barium titanate or calcium titanate. Since the end curved surface machining of the core holder is minimized, the machining time can be kept to a minimum compared to the conventional magnetic head.

〔Effect of the invention〕

As explained above, in the present invention, the radius of curvature of the curved surface at the inlet end of the floppy disk of the sliding contact surface of the magnetic head is machined to be large, and the curved surface at the outflow end is machined to the minimum radius of curvature as usual. This has the effect of improving the durability of both the floppy disk and the magnetic head, and providing an inexpensive magnetic head.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic head according to the present invention, and FIG. 2 is a perspective view of a magnetic head according to the present invention.
Figure AA sectional view, Figure 3 is a side view of another embodiment of the present invention,
FIG. 4 is a diagram illustrating the principle of the magnetic head portion during running of a floppy disk when using the magnetic head according to the present invention;
FIG. 5 is a perspective view of a conventional magnetic head, FIG. 6 is a gimbal spring assembly diagram, and FIG. 7 is a diagram explaining the principle of the magnetic head portion when a floppy disk is running when a conventional magnetic head is used. DESCRIPTION OF SYMBOLS 1... Magnetic head, 2... Core holder, 3... Recording/reproducing core, 4... Sliding surface, 5... Air groove, 6...
・Gimbal spring, 7...floppy disk. Figure Applicant Hitachi Maxell Co., Ltd. Representative Atsushi Nagai Figure 2 AA Chomen Figure 2 2. Name of the invention Magnetic head 3. Relationship with the case of the person making the amendment Patent applicant March 5, 1999, 7th day subject to amendment (text +' is R) (1) Specification, page 8, number 17 9th page 5th from line
The description up to line 1 is corrected as follows. "FIG. 1 is a perspective view of a magnetic head according to the present invention.

Claims (1)

[Claims] A core holder having a flat sliding surface for stable contact with the surface of a flexible magnetic recording medium, and a recording/reproducing core embedded in the core holder, In a magnetic head attached to a gimbal spring and held so as to be in sliding contact with the surface of the recording medium, the radius of curvature of the curved surface of the side that is perpendicular to the running direction of the sliding surface on the inflow end side in the running direction of the recording medium is: 1. A magnetic head for a flexible magnetic recording/reproducing device, characterized in that the radius of curvature of the curved surface of the side perpendicular to the running direction on the outflow end side of the running direction is 5 times or more.