JP4149176B2 - Magnetic disk unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic disk device.
[0002]
[Prior art]
In general, access to magnetic storage on a magnetic disk in a magnetic disk device is performed by a magnetic head that floats on the magnetic disk using an air flow generated on the magnetic disk as the magnetic disk rotates. The movement operation to the predetermined track is performed by a carriage arm that is rotationally driven around an arm rotation axis disposed on the side of the magnetic disk.
[0003]
Since the carriage arm is arranged so as to cross the radial region on the magnetic disk, it is easy to vibrate due to the influence of the air flow. Conventionally, the suppression of the vibration due to the air flow is a material mechanical, and It has been done by adjusting the control engineering characteristics.
[0004]
[Problems to be solved by the invention]
However, in recent years, the magnetic disk device has been increased in the rotational speed of the magnetic disk 2 in response to the demand for larger storage capacity and higher speed. In response to this, the position control of the carriage arm has become difficult, and there is a problem that the head positioning accuracy cannot be increased.
[0005]
An object of the present invention is to provide a magnetic disk apparatus capable of improving the head positioning accuracy by preventing the carriage arm from being vibrated by an air flow.
[0006]
[Means for Solving the Problems]
The vibration of the carriage arm 5 is caused by a vibration component having a relatively low frequency due to a high-speed air current colliding with the side surface in the longitudinal direction of the carriage arm 5 and a Karman vortex-like periodic unsteady vortex generated in the wake of the carriage arm 5. It is considered that vibration components having a relatively high frequency are included.
[0007]
The guide plate 6 according to the present invention guides the high-speed airflow generated on the upper surface of the magnetic disk 2 in the direction of the spindle 1 axis on the upstream side of the carriage arm 5, thereby reducing the flow velocity and flow rate of the high-speed airflow hitting the side surface of the carriage arm 5. As a result, the positioning accuracy of the carriage arm 5 is improved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 1 and 2, the magnetic disk apparatus has a plurality of magnetic members fixed in a stacked manner around the spindle shaft 1 in a space surrounded by a shroud 10 formed in a case 9. It is formed by disposing the disks 2, a carriage arm 5 holding the magnetic head 4 at the tip, and a magnetic circuit 7 formed at the other end of the carriage arm 5.
[0009]
The magnetic head 4 is bonded to the tip of the leaf spring suspension 8, and when the magnetic circuit 7 is excited, the carriage arm 5 is rotationally driven around the arm rotation shaft 3 positioned on the side of the magnetic disk 2, and a predetermined on the magnetic disk 2. The magnetic head 4 can seek to the position.
[0010]
The shroud 10 surrounds about 3/4 of the outer periphery of the magnetic disk 2 in the curvature portion 10a, and is then opened to the arm rotation shaft 3 side to form an arm working space 9a. The curvature portion 10a, the arm working space 9a wall surface, A small curvature wall 10b bulging inward is formed at the boundary portion. A stopper 11 for restricting the swing angle of the carriage arm 5 and a control unit (not shown) are disposed in the arm working space 9a.
[0011]
A plate block 12 in which a plurality of guide plates 6, 6... Project from the support column 12a to the side is erected and fixed in the arm working space 9a. As shown in FIG. 2, the guide plates 6 are provided at a pitch equal to the interval between the magnetic disks 2 and 2, and each guide plate 6 is fixed to the magnetic disk 2 from the outside of the magnetic disk 2 with the plate block 12 fixed. It arrange | positions so that it may be inserted in the clearance gap between them. The thickness (t) of the guide plate 6 is set so that a sufficient gap can be secured between the magnetic disk 2 and the disk surface without causing contact with the disk surface even when a disk flutter phenomenon occurs in the magnetic disk 2. The size (area) is determined in consideration of the material to be used so that the air flow generated with the rotation of the magnetic disk 2 can obtain a rigidity that does not flutter.
[0012]
Further, when a plate-like guide plate 6 is inserted between the magnetic disks 2, a strong shearing force acts on the air flow between the stationary guide plate 6 and the rotating magnetic disk 2, and the reaction thereof is as follows. The shearing force of the magnetic disk 2 increases. As a result, the power consumption (windage loss) accompanying the rotation of the magnetic disk 2 increases, so that each guide plate 6 goes from the upstream edge of the air flow to the downstream side as shown in FIG. Accordingly, a trapezoidal cross-sectional shape that gradually becomes thinner in the circumferential direction is formed, and an increase in power consumption is suppressed.
[0013]
The guide plate 6 formed as described above is arranged on the upstream side of the airflow carriage arm 5, that is, on the left side in this reference example in which the magnetic disk 2 is rotated counterclockwise. The upstream edge 6 a is arranged in a posture facing the direction of the rotation tangent of the magnetic disk 2. The distance (d) between the upstream edge 6a of the guide plate 6 and the small curvature wall 10b of the shroud 10 is such that the angle formed by the flow velocity vector direction of the air flow and the upstream edge 6a of the guide plate 6 is excessive. Thus, an appropriate value is set so that the flow rate of introduction into the arm working space 9a is reduced.
[0014]
Therefore, in this reference example , the air flow accompanying the rotation of the magnetic disk 2 is guided to the outside of the magnetic disk 2 by the upstream side edge 6a of the guide plate 6, that is, to the arm working space 9a side. The flow rate of the airflow that reaches is reduced and the carriage arm 5 is prevented from vibrating.
[0015]
FIG. 3 shows an embodiment of the present invention. In the description of the present embodiment, components that are substantially the same as those in the reference example described above are denoted by the same reference numerals in the drawing, and description thereof is omitted.
[0016]
FIG. 2 shows a position where the carriage arm 5 holds the magnetic head 4 on the innermost track or contact start / stop (CSS) region of the magnetic disk 2, that is, at the end of the rotation upstream swing stroke of the magnetic disk 2. In a certain state, the guide plate 6 is disposed on the carriage arm 5 at this position in a posture along the upstream side of the air flow. The tip of the guide plate 6 reaches the vicinity of the leaf spring suspension 8, and a gap with an appropriate interval is formed between the tip and the spindle shaft 1.
[0017]
Therefore, in this embodiment, the air flow flowing between the magnetic disks 2 collides with the upstream side edge 6a of the guide plate 6, and is then guided along the upstream side edge 6a in the direction of the spindle axis 1. It passes through the gap between the guide plate 6 and the spindle shaft, and goes out to the downstream side of the carriage arm 5. As a result, the flow velocity and flow rate of the air flow hitting the carriage arm 5 are reduced.
[0018]
【The invention's effect】
As is apparent from the above description, according to the present invention, it is possible to prevent the carriage arm from being vibrated by the air flow and to improve the head positioning accuracy.
[Brief description of the drawings]
FIG. 1 is a diagram showing a reference example of the present invention.
2A is a side view showing a positional relationship between a guide plate and a magnetic disk together with a relationship with a magnetic head, and FIG. 2B is a cross-sectional view taken along line 2B-2B in FIG.
FIG. 3 is a diagram showing an embodiment of the present invention.
[Explanation of symbols]
1 Spindle shaft 2 Magnetic disk 3 Arm rotation shaft 4 Magnetic head 5 Carriage arm
6 Guide plate

Claims (2)

A plurality of magnetic disks fixed on a rotating spindle shaft;
A carriage arm holding a magnetic head at a tip that is driven to rotate around an arm rotation axis disposed on the side of the magnetic disk and seeks on the magnetic disk;
The magnetic disk is arranged at a position along the carriage arm at the end of the rotation upstream swing stroke of the magnetic disk, and the air flow generated by the rotation of the magnetic disk is guided in the direction of the spindle shaft to reduce the collision flow to the carriage arm. A guide plate;
A magnetic disk device comprising: 2. The magnetic disk device according to claim 1, wherein the thickness of the guide plate gradually decreases along the rotation direction of the magnetic disk from the upstream edge of the air flow.

Images