JPH0259549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a magnetic disk device, and more particularly to the structure of an access device for a magnetic disk device that performs random access.

(b) Technical background In computer systems, magnetic disk devices are currently the most representative file devices and are widely used as basic components of disk-based systems, from small to large systems. Excellent access functionality,
It is heavily used for storing online data.

(c) Prior Art and Problems As is well known, a magnetic disk device includes a rotation drive mechanism that stably rotates the disk at a specified rotation speed, an access mechanism that moves the magnetic head and positions it on a desired track, and information on the disk. It consists of a write/read mechanism that writes and reads data, a control unit that controls traffic between the host device and the magnetic disk device, collates records, and controls the storage and reproduction of information, and a magnetic disk that stores information. has been done. The present invention relates to the above access mechanism.

The access mechanism slides the magnetic head onto the disk surface, keeps it afloat stably while keeping a constant minute distance from the disk surface, and moves it quickly and accurately to the selected track position.The accuracy of its positioning is record-setting. This is extremely important from the viewpoint of improving density.

FIG. 1 is a sectional view conceptually showing a conventional magnetic disk device. A spindle 2, which normally holds a plurality of magnetic disks 1 and rotates them at high speed, is supported by upper and lower ball bearings 4 mounted on a sturdy base plate 3, and is driven by a rotation drive device (not shown).

A cart 7 to which a head arm 6 supporting the magnetic head 5 is attached moves back and forth in the radial direction of the magnetic disk 1 while being guided by a linear guide mechanism (not shown) by a head drive device 8, thereby moving the magnetic head 5.
to the desired track position at high speed. The power of the head driving device 8 in this embodiment is provided by a moving coil type linear motor 11 comprising a stator 9 and a movable element 10 as shown in the figure. The track position is usually selected by reading position information written in advance on one side of the magnetic disk 1 or another fixed magnetic disk using the servo magnetic head 5a to control the linear motor 11.

The linear motor 11 is an actuator that converts electrical energy into mechanical energy.
As shown in the cross-sectional view of the figure, a yoke 13 made of soft iron, a central magnetic pole 14 and a permanent magnet 1 constitute a magnetic circuit.
5, and a movable part 10 consisting of a winding part 16 and a flange part 17 placed in an air gap magnetic field formed by a central magnetic pole 14. When a current is passed through the winding section 16, the winding section 16 moves in the axial direction under a direct force from the magnetic field, and the speed thereof is proportional to the current flowing through the winding section 16.

Also, the gap between the disk 1 and the magnetic head 5 is 0.2
Since the particles are as small as ~0.5 μm, even floating dust in the air can be a major hindrance, so a dust cover 12 is usually provided.

In such a structure, a huge reaction force is applied to the base plate 3 every time the truck 7 moves at high speed and stops, generating mechanical vibration that continues for a certain period of time. If you sit on the trolley 7, this reaction force will reach 10 to 20 kg. Therefore, each time a reaction force is applied, the base plate 3
This causes bending deflection due to mechanical vibration, reducing the access accuracy of the magnetic head device. The track pitch of recent magnetic disk devices is 20 to 50 μm.
Therefore, even a deformation of the base plate 3 of several micrometers will sensitively affect the positioning accuracy of the magnetic head 5.

As one of the above measures, it is possible to reduce the weight of the trolley as much as possible. The second method is
Instead of the cylindrical winding part 16 as shown in the figure, as schematically shown in FIG. is proposed. In the figure, four flat magnets 20 are arranged on a flat yoke 21 as shown, forming a magnetic circuit as shown by dotted lines. The moving coil 8 is also flat and the current flows perpendicular to the magnetic field, so the thin moving coil 18 moves in the direction of the arrow in response to mechanical force. Therefore, the thin moving coil 18
A magnetic head 5 (not shown) mounted on a flange 22 attached to a flat carriage 19 containing a magnetic head 5 can perform an access movement.

Compared to the case where the conventional cylindrical winding section 16 is used, the flat cart 19 and the thin movable coil 18 can be formed almost integrally, and a special connection part is not required. Instead, it is also possible to provide a hollowed-out portion 19a as shown in the figure, which has the advantage that the weight of the movable parts including the truck 19 can be easily reduced.

However, in the magnetic head drive unit 23 schematically shown in FIG. 3, the plane on which the flat cart 19 exists is parallel to the plane of the magnetic disk 1 to be written/read (indicated by a chain line in FIG. 4). In particular, as schematically shown in FIG. 4, when a plurality of flat magnetic disk access devices 24 are stacked to form a magnetic disk device, a magnetic The number of head 5 is 1
The structure is unsatisfactory in terms of both cost and high-density packaging. Some kind of structural improvement was desired.

(d) Object of the Invention The object of the present invention is to provide a structure in which a large number of magnetic heads can be attached to a lightweight flat magnetic head drive device.

(e) Structure of the Invention The object of the invention described above is to provide a moving coil motor including a thin moving coil and a stator, a truck to which the moving coil is attached, a linear guide mechanism for moving the truck in one direction, and a linear guide mechanism for moving the truck in one direction. In a magnetic disk access device consisting of a plurality of magnetic head arms each having a magnetic head at the tip disposed at one end of a cart, the flat cart is arranged in a plane perpendicular to the plane of the target magnetic disk. This can be easily achieved by providing a structure in which the plurality of magnetic head arms are provided on the front surface of the flat truck and a thin moving coil is provided on the side surface.

(f) Embodiments of the invention Examples of the invention will be described below with reference to the drawings. FIG. 5 is a perspective view showing an embodiment of a magnetic disk access device according to the present invention.

In the figure, the structure of the magnetic disk access device of this embodiment, which is composed of a flat cart 31, a thin moving coil 32, etc., is different from the conventionally proposed structure shown in FIG. As shown, the flat surface of the flat truck 31 provided with the thin moving coil 32 is disposed perpendicularly to the plane of the magnetic disk, and a magnetic head is supported at the front end of the flat truck 31. A plurality of magnetic head arms 6 are arranged in multiple stages.

That is, tapered slope guide portions 25 are formed at the top and bottom of the flat cart 31 as shown in the figure, and the flat cart 31 is fixed to the base plate 3 of the access device, as shown in the front view of FIG. It has a structure in which it is accurately guided by an outer ring of a ball bearing 26 provided on both sides of the slope guide portion 25 and moves back and forth. A plurality of magnetic head arms 6 are screwed in multiple stages to a flange 27 for attaching the magnetic heads 5, which is integrally disposed at the tip of the flat cart 31. Since the height of the flat cart 31 can be made relatively large, with this structure, the number of magnetic head arms 6 that can be attached can be considerably increased, making it possible to realize a multi-head access mechanism. is possible.

Furthermore, since two or three such flat magnetic head drive mechanisms can be installed in parallel and each can be controlled independently, the magnetic disk device is capable of high-speed writing/reading as a large-capacity storage device. It is extremely effective for configuring.

Furthermore, in order to reduce the weight of the flat truck 31, it is more effective to use ceramic as the material for the truck 31, as shown in FIG. Ceramic has the advantage of having lower density and greater rigidity than metal, superior wear resistance, and no eddy currents caused by magnetic fields.

To join the magnetic head mounting flange 27 and the flat cart 31, the joining surface of the ceramic flat cart 31 is metallized by means such as a molybdenum-manganese method, and then the magnetic head mounting flange 27 is placed in a hydrogen furnace. It is best to use metal brazing in terms of strength. In this case, it is necessary to use an iron-nickel alloy or the like which has a coefficient of thermal expansion similar to that of ceramic.

(g) Effects of the invention As is clear from the above explanation, if the flat magnetic head drive device of the present invention is introduced into a magnetic disk device, the weight of the moving part can be reduced by integrating the carriage and the movable part, and the weight of the moving part can be reduced. In addition to being able to reduce mechanical vibrations caused by force, it is also possible to configure a multi-head high-speed magnetic disk device by attaching many magnetic heads to a single truck, which was not possible with conventional proposals. .

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the structure of a conventional magnetic disk device, Fig. 2 is a sectional view showing the structure of a conventional cylindrical linear motor, and Fig. 3 is a sectional view showing the structure of a magnetic disk access device having a flat cart. 4 is a schematic diagram showing a configuration in which the magnetic disk access devices shown in FIG. 3 are stacked and used;
FIG. 5 is a perspective view showing the structure of an embodiment of the magnetic disk access device according to the present invention, FIG. 6 is a front view of the same, and FIG. 7 is a plan view showing the structure of a ceramic flat cart. . In the figure, 1 is a magnetic disk, 2 is a spindle, 3 is a base plate, 5 is a magnetic head, 6 is a head arm, 7 is a trolley, 8 is a head drive device,
9 is a stator, 10 is a mover, 11 is a linear motor, 12 is a dust cover, 13 and 21 are yokes, 1
4 is a central magnetic pole, 15 and 20 are permanent magnets, 16 is a winding portion, 31 is a flat plate-shaped truck, 32 is a thin moving coil, 22 and 27 are flanges, 23 is a magnetic head drive unit, and 24 is a flat magnetic disk access. In the device, 25 indicates a slope guide portion, and 26 indicates a ball bearing.

Claims (1)

[Scope of Claims] 1. A moving coil motor consisting of a thin moving coil 32 and a stator, a truck 31 to which the moving coil 32 is attached, a linear guide mechanism for moving the truck 31 in one direction, and the truck 31 In a magnetic disk access device consisting of a plurality of magnetic head arms 6 having a magnetic head 5 at the tip disposed at one end, a flat cart 31 is arranged in a plane perpendicular to the plane of the target magnetic disk. The flat trolley 3
1. A magnetic disk access device characterized in that the plurality of magnetic head arms 6 are provided on the front surface of the magnetic disk, and a thin moving coil 32 is provided on the side surface of the magnetic disk access device. 2. The magnetic disk access device according to claim 1, wherein said cart 31 is made of ceramic material.