JPS63127482A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To elevate a positioning accuracy between a disk and a magnetic head, and to improve the vibration characteristic of a spindle by forming a part between both fitting parts of a spindle fitting part and of a carriage fitting part into a cylindrical shape. CONSTITUTION:If a disk device 1 is divided roughly, it consists of a base assembly body 2, a disk cover 3, a carriage cover 4, a frame panel assembly body 5 and a circuit board 6. A cylinder shaped base 17 between both the fitting parts of a spindle fitting part 18 to fix the spindle onto a base and of a carriage fitting part 19 to fix a transferring means onto the base, is formed into the cylindrical shape by a die cast method. The base 17 comes to have a large twisting rigidity, and a relative positioning error between a point on a disk 12 and a head 11 being reduced, it comes to be a highly densificated truck, and the disk and the head being inserted from both the sides of the base 17, the handling of the disk can be safe.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and more particularly to a fixed magnetic disk device incorporating a base whose torsional rigidity is increased by making the base cylindrical.

[Conventional technology]

An example of the conventional technology will be described below.

(1) As described in JP-A-56-159879, by assembling a magnetic disk, spindle, magnetic head, carriage, and its support base from above onto a vessel-shaped base, and covering the upper part with a cover, The head disk assembly (HDA) was sealed from the outside air. However, no consideration was given to integrating the base cover to increase the rigidity of the cylindrical base, assembling the carriage support assembly and spindle assembly to the base from the front and back directions, and attaching the cover from the front and back.

(2) Some box-like structures have been proposed for the base of replaceable magnetic disk drives, but since it is below the magnetic disk puncture and the magnetic disk pack can be installed from above, Said Japanese Unexamined Patent Publication No. 1983-
There is no change in the box-shaped base used in Publication No. 159879 and its function, and it cannot be said that its operability and torsional rigidity 2 have been sufficiently increased within the limited height of the magnetic disk drive. hard.

(3) The base R4fd covers the magnetic disk pack from the side, but since the base between the spindle and carriage is not cylindrical, the positioning accuracy of the disk and head is affected by torsional vibration of the base. It must be said that the stability was lacking, and it was difficult to say that the disk could be attached after the head was mounted.

(4) The base and cover described in JP-A-56-169271 are split into front and rear parts with respect to the disk, but the installation of a spindle supported at both ends and the airtightness of the base and cover are shown. There is. However, this only describes the spindle attachment, and does not take into account the rigidity of the base between the spindle and the carriage support.

(5) JP-A-56-169272 has the above-mentioned (4)
) describes the carriage support system that was not mentioned in . Here, the carriage support has a bent thin plate shape relative to the cover. However, no measures have been taken to increase torsional rigidity, such as making it cylindrical.

In addition, as mentioned above, since the cylindrical structure is used as a cover for the carriage support and serves as the base that connects the spindle and the carriage, the rigidity of the cylindrical structure is directly useful for the head positioning system. It's hard to say that it is. Therefore, no consideration has been given to the fact that the rigidity of the cylindrical structure is related to the head positioning system.

[Problem that the invention seeks to solve]

Although the cover was designed to take full advantage of the height of the magnetic disk drive, the above conventional technology (5) used a thin plate bent carriage support, resulting in a head support system with low torsional rigidity, and the torsional rigidity of the base No consideration was given to increasing rigidity, and there was a problem in that positional deviation occurred between the magnetic head position and the magnetic disk due to torsional vibration.

An object of the present invention is to provide a base between a spindle and a carriage support, which has good vibration characteristics, and which can be called the minimum base for a positioning system, in order to improve the positioning accuracy between a disk and a magnetic head. It is in.

[Means for solving problems]

The above object is achieved by integrating the base and cover between the spindle support and the carriage support to form a cylindrical base. The torsional rigidity cannot be increased simply by fastening the base and cover together as in the conventional technology, and the cylindrical shape is essentially a cylindrical shaped product, or a cylindrical shape made by bending and a joint 2 formed by welding or strong bonding. Dine closed items.

In addition, the cylindrical base does not need to be made of a single material; it may be a composite layer material using multiple materials in the thickness direction, a solid shaped material with special inclusions or surface layers, or a cylindrical base in the circumferential direction or axial longitudinal direction. Even if a plurality of materials are used partially or locally in the direction, the rigidity is not affected in any way and it can be used.

In addition, if the tube is shaped like a tube, even if the inside of the tube is locally modified, as long as the outer surface shape remains unchanged, the decrease in rigidity will be slight.

Further, even if there are slight holes or deformations on the outer surface of the cylindrical shape, the rigidity will not be significantly reduced.

[Effect]

The cylindrical base has torsional rigidity, as stated in general material mechanics, even in the hollow part, the base material is bent (
Compared to conventional bases, which only have torsional rigidity equal to approximately the plate cross-sectional area of the base (U-shaped cross-sectional shape), the cylindrical base has about 20 times the difference in torsional rigidity. Therefore, for bases of the same weight, the positioning error due to torsional vibration of the cylindrical base is reduced to about 1/20, and a highly accurate head positioning system can be provided.

Conventional bases (U-shaped) were quite heavy because the base part between the spindle and carriage, which required increased torsional rigidity, and the base part and cover part necessary for other sealing were almost the same as the base.

However, it can be seen that the cylindrical base is used only in the parts where rigidity is required, and that the torsional rigidity is not affected in any way even if the other sealed parts are covered with a different material. In addition, instead of having a flat plate shape like the cover of the prior art (1), the proposed cover can easily be made into a box shape, and even a thin plastic material can provide a cover that is sufficiently airtight and resistant to deformation.

〔Example〕

Is the following an example of the present invention? This will be explained with reference to FIG.

In FIG. 1, each part of the disk device 1 is disassembled for explanation.

The device is roughly divided into a base assembly 2, a disk cover 3, a carriage cover 4, and a frame panel assembly 5.
and a circuit board 6.

In the apparatus, a disk cover 3 and a carriage cover 4 are usually fastened to the base assembly 2, and the joints are sealed to prevent outside air from introducing dust and the like into the base assembly 2. Additionally, this work is performed in a dust-proof work area where the air dust level is low and controlled.

This assembly is assembled into head disk assembly 7 (abbreviation: J).
It is called DA) and is fastened to a shock mount 8 on the frame panel assembly 5 to prevent shocks and vibrations from the frame 9 from being transmitted to the HDA 7. The circuit board 6 electrically controls the disk device, controls the 70M14 (voice coil motor) for rotating the motor 10 and moving the magnetic head 11, and reads, writes, and interprets information.

The base assembly 2 includes a spindle 13 for rotating a plurality of disks 12, and a cylindrical base 17 for fixing a carriage support 16 for supporting a carriage 15 for rotationally moving the magnetic head 11.

The cylindrical base 17 is made into a cylindrical shape from the same material by an aluminum die-casting method, and then the spindle attachment part 18 and the carriage support attachment part 19 are processed.

The carriage support 16 supports the magnetic head 11 and the carriage 1.
5. Voice coil 21, head amplifier circuit 22, FPC
(Flex Printirado Circuit) 23, carriage shaft 24, carriage 15
magnetic head 11, head amplifier circuit 22 and FPC 23
A voice coil 21 is connected and assembled, and is rotatably movable about a carriage shaft 24 as a center of rotation. The carriage shaft 24 is attached to the cylindrical base 17 from one side, and the magnetic head 11 is fixed thereon by a suitable head jig 25 so that the disk 12 can be inserted therein until the disk 12 is assembled.

On the other hand, after the disk 12 is assembled to the spindle 13, the disk 12 is inserted into the cylindrical base 17 through the other hole of the cylindrical base 17 opposite to the one where the carriage shaft 24 is installed, so as not to contact the magnetic head 11 and be damaged. After being assembled, the head jig 25 is removed, and the magnetic head 11 lands on the surface of the disk 12, completing the assembly.

If necessary, writing, reading, verifying, etc. in the servo track writer 26 and error tester 7 can be performed at this point. Since these are done in a state closer to the final product than what was done before the conventional disk 12 was assembled and the magnetic hect 11 was assembled, the magnetic head 11 assembly reduces the effects of assembly distortion that sometimes occurs. Further, since the assembly can be performed in the reverse order of the assembly, even when replacing the disk later, the number of times the magnetic head 11 must be removed and attached can be reduced. The magnet g26t of the voice fill motor (VCM) 14 is attached to the device in this state! ff with Ji, FP
If you connect C23 to the circuit board 6 and operate the circuit,
For disk devices! It is also possible to confirm the function as 1.

After this, if the carriage cover 4 and disk cover 3 are assembled, the head disk assembly (HDA) 7 is completed, and the HDA 7 and circuit board 6 can be attached to the shock mount 8 and frame 9 on the frame panel assembly 5, respectively. The device is then completed.

Note that the VCM may be a step motor. Further, this actuator may be a rotary type or a linear type actuator.

〔Effect of the invention〕

According to the present invention, since the torsional rigidity of the cylindrical base 17 between the spindle mounting part 18 and the carriage mounting part 19 can be increased, the relative positioning error between a point on the disk 12 and the magnetic head 11 can be reduced by 2, and the height can be increased. This has the effect of realizing a densified track.

In addition, since the disk 12 and magnetic head 11 are inserted from both sides of the cylindrical base 17, and sufficient movement space is provided for each insertion jig, it is possible to incorporate surface scratches on the magnetic disk 12 caused by the magnetic head 11. The base part, which is important for head positioning, has been minimized to reduce the damage caused during work or removal.
Since the areas necessary for DA sealing are clearly covered, the amount of aluminum used for the base can be reduced to a fraction of that of conventional models, resulting in a low-cost base.

The cross-sectional shape of the base has also changed from a box-like shape to a cylindrical shape, making it more resistant to deformation, making it a groove structure that is strong enough to withstand external forces and deformation over time.

Since the base shape is symmetrical in both the left and right directions, the shape remains similar even to thermal deformation caused by temperature changes, making it easier to correct for thermal deformation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a conventional example. 1... Disk device, 2... Base assembly,
3... Disk cover, 4... Carriage cover, 5... Frame panel assembly 6... Circuit board, 7... Head disk assembly (HDA), 8
... Shock mount, 9... Frame, 10...
- Motor, 11... Magnetic head, 12... Disk, 16... Spindle, 14... VCM (voice coil motor), 15... Carriage, 16... Carriage support, 17... - Cylindrical base, 18... Spindle mounting part, 19... Carriage support mounting part, 20
...Panel, 21...Voice coil, 22...Head amplifier circuit, 23...FPC, 24...Carriage shaft, -25...Head jig, 2
6... Magnet part, 27... Box-shaped base, 28... Flat plate cover.

Claims (1)

[Claims] 1. A magnetic head, a carriage that supports the magnetic head,
A spindle in a magnetic disk drive comprising a transport means for moving a carriage, a drive means for the carriage, a disk, a spindle, a head disk assembly consisting of a base and a plurality of covers, a circuit board and a frame assembly. What is claimed is: 1. A magnetic disk drive comprising: a spindle mounting section for fixing the magnetic disk to the base; and a carriage mounting section for defining the transfer means on the base; the base shape between the two mounting sections is cylindrical. 2. The magnetic disk drive according to claim 1, wherein the carriage transfer method is a rotation type, and the transfer means is a carriage shaft located at the center of rotation of the carriage and a support for the shaft. disk device. 3. A magnetic disk drive according to claim 1, wherein the carriage transport method is a direct-acting type, and the transport means is a slider mechanism that moves the carriage in a straight line.