JP3141253B2 - Head support device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head supporting device for supporting a floating head or a sliding head for a rotating magnetic recording medium, for example, a hard disk (HD).

[0002]

2. Description of the Related Art A floating magnetic head in a drive device for a rotating magnetic recording medium, for example, a magnetic disk such as an HD,
For example, as shown in an enlarged schematic perspective view of FIG. 4, an operating magnetic gap is opposed to the medium 1 of the slider 5 in a rotating magnetic recording medium 1 that rotates at a high speed, for example, a slider 5 that floats by an airflow caused by rotation of an HD. Flying surface so-called ABS
(Air bearing surface) 7.

The slider 5 has a magnetic recording medium 1 which rotates against suspension of the slider 5 by a suspension 8.
It is pressed and supported with a required pressing force toward the side. In this way, the slider 5 is moved to the rotating magnetic recording medium 1.
During the rotation of the medium 1, the required flying height is maintained with respect to the medium 1, and the operating magnetic gap of the magnetic head element 6 is held so as to face the rotating magnetic recording medium 1, that is, the HD surface, with a required distance. You.

The suspension 8 has a holding spring 9, a so-called load beam, made of a leaf spring having one end fixed to a fixed portion 19, and a gimbal 10 attached to its free end by welding at a welding point 11.

The gimbal 10 is formed of, for example, a band-shaped elastic plate as shown in a schematic perspective view of FIG.
A bent groove is provided at the center thereof, and this is fitted into a groove 12 provided on the opposite side of the ABS 5 of the slider 5 as shown in FIG. An elastic tongue 13 is cut into a bent groove at the center of the gimbal 10 and a projection 14 bulging upward.
Is provided.

On the other hand, the tip of the holding spring 9 abuts against the projection 14 of the gimbal 10 so that a required pressing force is applied to the slider 5.

The restraining spring 9 is formed in a triangular shape whose width is gradually reduced toward the slider 5 side, that is, toward the free end side, and is set so that the natural frequency of elastic vibration increases. Further, in order to increase the dynamic rigidity, ribs 15A and 15B formed by bending these edges in one direction are provided on both side edges thereof. It has been.

The holding spring 9 of the suspension 8 having such a configuration is actually exposed to the airflow accompanying the high-speed rotation of the rotating magnetic recording medium 1. In particular, when the diameter of the rotating magnetic recording medium 1 is increased or the rotation speed is increased, the influence of the air flow applied to the restraining spring 9 accompanying the rotation cannot be ignored. That is, when the air flow indicated by the arrow a in FIG.
The lift spring shown by the arrow FL is generated in the holding spring 9 of
A drag FR in a direction orthogonal to this occurs.

Many analyzes have been made on the air flow with respect to the restraining spring and on the lift generated in the restraining spring due to the air flow (for example, materials of the Magnetic Recording Research Group of the Institute of Telecommunications, MR91-10, "Magnetic Head"). Numerical analysis of flying height fluctuation and positioning error due to hydrodynamic vibration of support system ”).

FIG. 7 is a schematic diagram of an air flow based on rotation of the rotary magnetic recording medium 1 with respect to the magnetic head restraining spring 9.
In this case, the large-scale vortex e _{A is formed} by the upstream rib 15A.
Although but the vortex e _B generated in the downstream side ribs with generated, and the downstream side of the rib 15B generates a separate vortex In the outside Most large eddy e _B by the upstream side of the rib 15A . These vortices serve as a source of fluid force acting as a disturbance on the suppressing spring 9. In this case, the retaining spring 9 is easily excited at the natural frequency, but at the same time, the main frequency of the above-mentioned fluid force acting on the retaining spring 9, for example, the main frequency of each periodic vibration in the direction in which the lifting force and the drag of the retaining spring 9 act. Is different from the natural frequency of the restraining spring 9, it is also known that the restraining spring 9 vibrates at the natural frequency.

The vortex around the restraining spring 9, which is a source of the fluid exciting force, is formed by sharp edges having the ribs 15A and 15B bent at both side edges of the leaf spring. It is caused by that.

Further, since this vortex changes with time, the lift and the drag acting on the restraining spring 9 are extremely unstable, which change with time.

[0013]

According to the present invention, a magnetic head, such as a slider, is supported with a required pressing force against a rotating magnetic recording medium, such as an HD, by the above-mentioned restraining spring having ribs on both side edges, ie, reinforcing edges. In the case where the flying height is set or the magnetic head is brought into contact with the rotating magnetic recording medium, in the case where the contact pressure is applied, the air due to the rotation of the rotating magnetic recording medium is used. A stable magnetic recording / reproducing characteristic is obtained by reducing an unstable fluid exciting force to a restraining spring due to a flow.

[0014]

According to the present invention, as shown in a schematic perspective view of an example in FIG. 1, a magnetic head provided with ribs 2 in a direction crossing an air flow generated by a rotating magnetic recording medium 1 is provided. In the magnetic head supporting device having the restraining spring 3, the rib 2 has a laminar flow blade sectional shape, that is, a so-called streamlined outer shape with respect to the direction of the air flow applied thereto, as shown in an enlarged sectional view of FIG. The shape shall be bent into a smoothly curved shape.

In another embodiment of the present invention, as shown in FIG. 2, ribs 2 on both side edges of a magnetic head restraining spring 3 are respectively formed hollow, and at least one end (one end in the longitudinal direction), for example, both ends 2A And 2B are opened, for example, into a cylindrical shape having a laminar flow blade cross section, and a large number of pores 4 are formed in the wall surface of the hollow body.

[0016]

According to the construction of the present invention described above, the ribs 2 provided on both sides of the magnetic head restraining spring 3 have laminar flow blade cross-sectional shapes, thereby effectively preventing the generation of eddies due to the air flow applied thereto. Thus, fluctuations in the lift and drag applied to the entire magnetic head restraining spring 3 can be effectively avoided, and the magnetic head can be stably supported.

That is, as shown in FIG. 3A, when a laminar airfoil cross-sectional shape is arranged in an airflow, as is well known, the air flows close to the surface of the airfoil. In order for the air to flow closely to the surface, the velocity (the partial layer where the velocity suddenly drops due to viscosity near the wing surface is called a boundary layer denoted by reference numeral 31; The velocity of the inviscid flow (also called the potential flow) present at the surface must vary along the surface. As shown in FIG. 3B, the velocity is zero at the leading edge A, then increases to a maximum, and then decreases to zero again at the trailing edge C. According to Bernoulli's theorem on potential flow, pressure is high at high speed and low at low speed. Part B is the lowest. By retreating the position where the lowest pressure is generated along the blade surface, the boundary layer is laminar (the boundary layer has two types of flow, laminar flow and turbulent flow. The so-called laminar flow blade cross-section has a greatly extended range in which the loss is small and therefore the frictional resistance is small), and a remarkable reduction in the resistance can be achieved. As described above, when the ribs 2 are hollow and the end portions are opened to form the pores 4 on the wall surface, the position where the boundary layer leaves the wing surface is effectively retracted. be able to.
That is, the air suction action causes the separation point of the boundary layer to recede.

This can be qualitatively explained as follows. That is, for simplicity, assuming a two-dimensional boundary layer flow that does not shrink, Equation 1 holds along the streamline on the blade surface (y = 0).

(Equation 1) In this case, the deceleration region where dP / dx> 0 (in FIG.
In the boundary layer between C), the curvature (∂ ² u / ∂y ² ) _{y = 0 of} the velocity profile u becomes smaller than the air suction effect, so that the separation of the laminar boundary layer can be reduced.

Further, by forming a large number of small holes 4 in the rib 2, the weight of the restraining spring 3 can be reduced, and the resonance characteristics of the spring can be improved.

In the above description, the case where the support system of the magnetic head is stationary has been described. However, the same effect of the so-called seek movement of the magnetic head can be reduced, and the like. , Enabling faster seek movements.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a flying magnetic head will be described in detail with reference to FIG. In this case, as described with reference to FIGS.
However, a slider 5 is provided with its operating magnetic gap facing the air bearing surface, that is, the ABS 7, and the slider 5 is supported by the suspension 8.

The suspension 8 includes the magnetic head restraining spring 3 and the gimbal 10 described with reference to FIG.

The base side of the magnetic head restraining spring 3 is fixed to a fixing portion 19, and a gimbal 10 is attached to its free end to support the slider 5, that is, the magnetic head element 6 as usual. It is so.

Since the gimbal 10 has the same configuration as that of FIG. 5, the same reference numerals in FIG. 1 denote parts corresponding to those in FIGS. 4 and 5, and a duplicate description will be omitted.

In the present invention, in particular, the magnetic head restraining spring 3 has a leaf spring structure made of an elastic metal plate or the like, and has a generally triangular shape as a whole which gradually narrows toward its tip. However, both side edges thereof are curved inward so that the outer shape of the cross section becomes the laminar flow blade cross-sectional shape, and are formed into a cylindrical shape having both ends 2A and 2B open. Then, a fine hole 4 is formed in each of the wall surfaces.

According to such a configuration, even when the magnetic head restraining spring 3 is arranged in the air flow generated by the rotation of the rotary magnetic recording medium 1, turbulence is generated by the protrusion of the rib 2. Is effectively avoided as described above, so that a small and stable lift and drag are generated. Therefore, the slider 5, that is, the magnetic head element 6 is moved to a predetermined position during recording and reproduction on the rotating magnetic recording medium 1 during rotation. , And stable recording and reproduction can be performed. In the above-described example, the present invention is applied to a floating magnetic head. However, the present invention is not limited to the floating magnetic head, and a magnetic head holding spring may be used to convert the magnetic head to a rotating magnetic recording medium such as a floppy disk. The present invention can be applied to a case where a structure in which contact and contact are performed by a contact pressure is adopted.

[0027]

As described above, according to the structure of the present invention, since the rib 2 of the holding spring 3 of the magnetic head element 6 has a laminar flow blade cross section, the rotation of the rotary magnetic recording medium 1 caused by the rib 3 is achieved. Since the instability such as suppression and drag caused by airflow is improved, the flying height or contact of the magnetic head element 6 with respect to the magnetic recording medium 1 even when a large-diameter rotating magnetic recording medium or a high-speed rotating magnetic recording medium is used. Since the pressure can be kept constant, the occurrence of vibration can be effectively avoided, the spacing of the magnetic head element 6 with respect to the medium 1 can be kept constant, and stable recording and reproduction can be performed.

The target position of the magnetic head on the magnetic recording medium 1 with respect to a constant drive current is reduced by reducing the air resistance acting on the support system of the magnetic head and reducing the weight when the fine holes 4 are provided. Seek at a constant drive current to the
It brings many benefits such as shortened access time.

[Brief description of the drawings]

FIG. 1 is a schematic enlarged perspective view of an example of a magnetic head support device according to the present invention.

FIG. 2 is a cross-sectional view of a rib of a magnetic head restraining spring according to the present invention.

FIG. 3 is an airflow diagram of a laminar flow blade cross-sectional shape for explaining the operation of the apparatus of the present invention.

FIG. 4 is a schematic enlarged perspective view of an example of a conventional magnetic head support device.

FIG. 5 is a perspective view of the gimbal.

FIG. 6 is a sectional view of a holding spring.

FIG. 7 is a diagram showing an air flow caused by a rib of a magnetic head restraining spring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary magnetic recording medium 2 Rib 3 Magnetic head restraining spring 4 Pores 5 Slider 6 Magnetic head element

Claims (2)

(57) [Claims] 1. A head supporting device having a head restraining spring provided with a rib in a direction crossing an air flow generated by a rotary recording medium, wherein the rib has a laminar flow blade cross-sectional shape, and a rib having the laminar flow blade cross-sectional shape. A head support device characterized in that at least one end of the hollow body is open, and a number of pores are formed in the wall surface of the hollow body. 2. The head supporting device according to claim 1, wherein the fine holes are provided on an upper surface side of the laminar flow blade cross-sectional shape.