JPS5918780B2 - Adsorption floating magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floating magnetic head that takes off and lands in contact with a magnetic disk when starting and stopping the rotation of the magnetic disk.

A floating magnetic head that takes off and lands on a magnetic disk is connected to a contact start/stop.
It is called a C, S-S) type magnetic head, and unlike conventional floating magnetic heads, the load to generate air bearings is large, so C, S, and S cannot be performed, and the magnetic disk cannot rotate at high speed and steady. Since there is no complicated loading mechanism that brings the magnetic head closer to the magnetic disk after reaching the magnetic disk, it has excellent advantages in terms of improving device cost and reliability. Since they make contact and take off, it is necessary to reduce the sliding distance as much as possible in order to reduce the sliding wear on the slider and disk. For this purpose, it is also necessary that the takeoff and landing speeds in C, S, and S be as low as possible. A large slider buoyancy force when the magnetic disk is at low speed means that takeoff and landing speeds are low, but when the magnetic disk reaches a high steady speed, it generates a large buoyant force, which is balanced by a constant load. Therefore, the flying height, that is, the spacing between the magnetic disk and the slider becomes very large.

In order to obtain the desired spacing, a large load is required, and the contact pressure of the slider against the magnetic disk during C, S, and S increases, increasing the amount of sliding wear. Therefore C,
During takeoff and landing at S and S, a large buoyant force is generated to reduce the takeoff and landing speed, and it is desirable that the buoyant force not increase even when the magnetic disk rotates at high speed, and that a predetermined spacing can be obtained without increasing the load. The purpose of this invention is to provide a suction floating type that has a large buoyancy when the rotational speed of the magnetic disk is low, does not increase the buoyancy even when the rotational speed is high, and can obtain a predetermined spacing without changing the load. The objective is to obtain a magnetic head.

The present invention is characterized by a floating magnetic head consisting of a floating part that receives buoyancy from the air viscous laminar flow generated by the movement of a recording medium, and a magnetic head part supported by the air outflow end of this floating part. , an angle of attack formed at the air inflow end of the floating section, a floating surface formed so as to generate a positive buoyancy force on the surface of the floating section facing the recording medium, and at least the intersection of the angle of attack and the floating surface of the floating section. It has a suction surface that is tapered to generate negative buoyancy from a portion near the air inflow end toward the rear end of the floating section.

Embodiments of the present invention will be described below with reference to the drawings. In Fig. 1, a slider 2, which controls a part of the magnetic circuit of a magnetic head part 1 made of a magnetic material such as ferrite, has an angle of attack part 3 and a number of floating surfaces 4, and has a positive buoyancy when floating. Make it a face. Further, between each of the floating surfaces 4, a large number of suction surfaces 5 are provided which have a negative angle of attack when floating and therefore have a negative buoyancy, that is, a suction force. The suction surface 5 is tapered from a portion closer to the air inflow end than an intersection 13 between the attack angle 3 and the floating surface 4 (the apex of the attack angle 4) toward the air outflow end. Such a slider 2 is fixed and supported in a groove 8 provided in the slider 2 by using the elasticity of a claw 7 formed in a gimbal 6 as shown in FIG. Although not specifically shown in FIG. 2, pressure due to deflection of a spring or the like is applied to the slider 2 as a load 9. When the magnetic disk 10 is rotated in the direction of the arrow 11, a coating 12 which is a magnetic recording medium applied on the magnetic disk
The floating surface 4 of the slider 2 begins to slide on the soil.

As the circumferential speed gradually increases, the pressure distribution due to the air viscous laminar flow generated on the floating surface 4 becomes as shown in FIG. The pressure starts from atmospheric pressure at the tip of the slider 2, reaches a maximum at the apex 13 of the angle of attack 3 due to air being compressed, decreases once entering the floating surface 4, and then returns to the rear end 14. known to be the largest.

The circumferential speed of the magnetic disk 10 increases, the slider 2 floats, and the spacing 15 finally exceeds the maximum convexity of the coating 12 and takes off. The spacing and maximum protrusion amount at this time are approximately 0.025μ. The suction pressure distribution 17 of the suction surface 4 is as shown in FIG. 3 with respect to the take-off pressure distribution 16, which is negative pressure,
The floating blade is obtained by multiplying the sum average value 20 resulting from the difference between the positive average value 18 of the adsorption pressure distribution 17 and the negative average value 19 of the adsorption pressure distribution 17 by the area of the floating surface 4 and the angle of attack part 3, which balances the load in Figure 2. . When the magnetic disk 10 reaches steady rotation at high speed, the pressure distribution becomes as shown in FIG.

The floating blade has a steady pressure distribution 21, a steady adsorption pressure distribution 22, and a sum average value 2 which is the difference between the positive average value 18 and the negative average value 19.
0 times the floating area. Here, the sum average value is 20
Even if the positive average value increases, the suction pressure distribution 17 by the suction surface 5 becomes stronger, and the negative average value 19 also has a large difference.The sum average value 20 is almost the same as the positive average value 18 at the time of takeoff, and the predetermined spacing is obtained. In this case, it is clear that if there is no suction surface 5, the floating blade will be extremely large and a large load 9 will be required. Therefore, by providing the suction surface 5, a predetermined spacing can be obtained. There is no need to change the load. In addition, since the suction surface 5 is formed from the middle of the angle of attack 3, the minimum gap of the suction surface 5 is always sufficiently larger than the minimum gap of the floating surface 4, so that it can withstand fluctuations in the amount of floating soil on the floating surface 4. The rate of change in the gap between the suction surfaces 5 is small.

Therefore, the floating blade fluctuates greatly in response to fluctuations in the flying height, producing a restoring force, whereas the suction force produces a nearly constant force, resulting in high air film rigidity.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the suction floating type magnetic head according to the present invention as seen from the floating surface, Fig. 2 is a side sectional view of the floating state, Fig. 3 is the floating surface at takeoff, pressure distribution on the adsorption surface, and Fig. 4 is the fixed Constantly floating surface and adsorption surface pressure distribution.

Claims (1)

[Claims] 1. A floating magnetic head consisting of a floating part that receives buoyancy from the air viscous laminar flow generated by the movement of a recording medium, and a magnetic head part supported by the air outflow end of the floating part,
An angle of attack formed at an air inflow end of the floating section, a floating surface formed so as to generate a positive buoyancy on a surface of the floating section facing the recording medium, and an intersection of at least the angle of attack and the floating surface of the floating section. What is claimed is: 1. A suction floating magnetic head comprising a suction surface tapered to generate negative buoyancy from a portion closer to an air inlet end toward a rear end of the floating section.