JP2683139B2 - Voice coil motor for magnetic disk drive - Google Patents

Description

The present invention relates to a voice coil motor as a magnetic head transfer motor incorporated in a magnetic disk drive device using a hard disk.

[Conventional technology]

A magnetic disk drive device using a hard magnetic disk, a so-called hard disk, supports a magnetic head on one end side of a support member and swings the support member by a magnetic head transfer motor to move the magnetic head to the hard disk. It is designed to be transported in the radial direction, and the air flow generated on the surface of the hard disk rotating at high speed is used to levitate the magnetic head slightly above the surface of the hard disk,
Writing and reading of signals are performed.

By the way, in recent years, personal computers incorporating this type of magnetic disk drive have been increasingly miniaturized and thinned. Therefore, there is a strong demand for miniaturization and thinning of the magnetic disk drive, but it has already been saved in various ways. Space saving has been devised, and voice coil motors have been used instead of stepping motors for magnetic head transfer motors.

This voice coil motor is also called a moving coil type motor and is arranged at a corner of a chassis. A moving coil mounted on a supporting member such as a swing arm is placed between a pair of upper and lower yokes via a flat permanent magnet. The movable head is movably interposed and the movable coil is moved along the permanent magnet by controlling energization to the movable coil so that the supporting member can be swung to transfer the magnetic head. There is.

Conventionally, such a voice coil motor is assembled by screwing a lower yoke to which a permanent magnet is fixed to a chassis and then screwing an upper yoke onto the lower yoke via a plurality of columns, thereby constructing a plurality of The movement range of the movable coil is regulated by bringing the outer peripheral surface of the movable coil into contact with two of the columns, and the transfer of the magnetic head is guaranteed between the innermost peripheral portion and the outermost peripheral portion of the hard disk. It is getting done.

[Problems to be solved by the invention]

By the way, in order to further miniaturize the above-mentioned magnetic disk drive device, it is indispensable to improve the space factor of the voice coil motor, but on the other hand, due to structural restrictions, the miniaturization of the voice coil motor yoke is required. It was said that there was a limit to the conversion. That is, conventionally, there is a constraint that a plurality of columns that support the upper yoke on the lower yoke are arranged in a well-balanced manner outside the moving range of the moving coil in consideration of the attractive force of the permanent magnet. Corresponding to the arrangement of the plurality of columns, the yoke also has to be selected to have a shape slightly protruding outside the moving range of the movable coil. Further, when the yoke is formed as small as possible, the screwing work for connecting the upper and lower yokes becomes complicated, and deterioration of the assembling property is expected.

The present invention has been made in view of such a technical background. A first object of the present invention is to provide a voice coil motor that is easy to assemble even if it is downsized, and the second object of the present invention. It is an object of the present invention to provide a voice coil motor which has a good space factor and can promote miniaturization of a magnetic disk drive device.

[Means for solving the problem]

In order to achieve the above-mentioned first object, the present invention provides a movable coil attached to the other end side of a support member having a magnetic head attached to one end side of a pair of upper and lower yokes via a flat permanent magnet. In a voice coil motor of a magnetic disk drive device movably interposed therebetween, the attraction center of the permanent magnet is provided inside a polygon having a plurality of struts supporting one yoke on the other yoke as vertices. In addition to the arrangement, the tips of the columns are brought into contact with each other, and one of the yokes is fixed on the other yoke by the attractive force of the permanent magnet.

In order to achieve the second object, the present invention is
A voice coil of a magnetic disk drive device in which a movable coil attached to the other end of a support member having a magnetic head attached to one end is movably provided between a pair of upper and lower yokes via a flat permanent magnet. In the motor, at least one of a plurality of columns that supports the one yoke on the other yoke is arranged in the air core portion of the movable coil.

[Action]

If the attraction center of the permanent magnet is located inside the polygon with multiple struts at the apex, the pair of upper and lower yokes can be connected easily and reliably by the attraction force of the permanent magnet and the positioning function of each stanchion. Therefore, complicated screwing work is unnecessary. Further, if at least one support column is arranged in the air core portion of the movable coil, it is only necessary to dispose at least two support columns outside the moving range of the movable coil, and the space factor is improved. It is also possible to regulate the moving range of the movable coil by the support column in the air core part.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 are for explaining a voice coil motor according to an embodiment of the present invention. FIG. 1 is a partial cross-sectional side view showing a structure of a pair of upper and lower yokes, and FIG. FIG. 3 is a plan view of the upper yoke, and FIG. 4 is a plan view showing a relational position between the movable coil and the yoke.

In these drawings, the yoke of the voice coil motor is arranged on the lower yoke 2 via a substantially fan-shaped lower yoke 2 having a plate-shaped permanent magnet 1 fixed to the upper surface and three columns 3, 4, 3. The upper yoke 6 is also combined with a substantially fan-shaped upper yoke 6 that is supported, and the fourth yoke is provided between the pair of upper and lower yokes 2 and 6.
A movable coil 7 shown in the figure is movably provided along the permanent magnet 1. Both ends of the two columns 3 and 5 located outside the permanent magnet 1 are fitted and adhered to the lower and upper yokes 2 and 6, but the central column 4 has a lower end surface. Is brought into contact with the permanent magnet 1, and only the upper end is fitted and adhered to the upper yoke 6. Then, as shown in FIG. 2, the center of gravity G corresponding to the attraction center of the permanent magnet 1
Is located inside a triangle with these three columns 3, 4 and 5 as vertices, and the upper yoke 6 attracted by the permanent magnet 1.
Can be supported in good balance by the three columns 3, 4, 3. A damper 8 made of a rubber ring or the like is attached to a part of the center column 4, and the moving range of the movable coil 7 can be reduced by bringing the inner peripheral surface of the movable coil 7 into contact with the damper 8. It is becoming regulated.

FIG. 5 is a plan view showing the internal structure of a magnetic disk drive device 10 incorporating such a boil coil motor 9.

In FIG. 1, a magnetic disk drive device 10 includes a chassis 11 formed by an aluminum die cast, a frame (not shown) for holding the chassis 11 and mounting the chassis 11 on a main body device, and the chassis 11 rotatably. An axially supported hard disk 13, a magnetic head 14 for writing and reading a signal to and from the magnetic recording layer of the hard disk 13, and a magnetic head 14 mounted on one end side via a support spring 15 and on the other end side. A swing head 17 as a supporting member to which the movable coil 7 is attached and which is rotatably supported by a support shaft 16, and a magnetic head transfer motor in which the movable coil 7 is interposed between a pair of upper and lower yokes 2 and 6. The voice coil motor 9 as described above, a lid (not shown) for sealing each member mounted on the upper surface side of the chassis 11 via an O-ring 18, and a drive control circuit on the lower surface side of the chassis 11. It is mainly composed of a mounted printed wiring board (not shown).

When assembling the voice coil motor 9, first, the lower yoke 2 having the columns 3 and 5 fixed in advance is screwed onto the chassis 11 using the mounting holes 2a and 2b, and the permanent magnet 1 is attached. After arranging the movable coil 7 integrated with the swing arm 17 at a position facing the swing arm 17, the struts 3 and 5 are fitted into the mounting holes 6a and 6b of the upper yoke 6 in which the struts 4 are fixed in advance, and the central struts 4 are inserted. Passes through the air-core portion 7a of the movable coil 7 and is brought into contact with the permanent magnet 1. As a result, the upper yoke 6 is reliably placed and fixed on the lower yoke 2 by the attraction force of the permanent magnet 1 and the positioning function of the three columns 3, 4, and the two yokes 2, 6 are connected. The screwing work to do this is unnecessary.

Further, the voice coil motor 9 controls the energization of the movable coil 7 to move the movable coil 7 along the permanent magnet 1 so as to swing the swing arm 17 at this time. , The central column 4 functions as a stopper for restricting the moving range of the movable coil 7, and the magnetic head is provided between the innermost peripheral portion and the outermost peripheral portion of the hard disk 13.
Guaranteed 14 transfers. That is, since the inner peripheral surface of the movable coil 7 maintains a high dimensional accuracy due to the convenience of the winding, the movable coil 7 is contacted with the inner peripheral surface of the damper 8 of the central support shaft 4 by the contact. The maximum amount of movement can be specified with high accuracy. Furthermore, the moving coil 7
Since the column 4 is arranged in the window core portion 7a of the above, stable support of the upper yoke 6 is realized only by arranging the two columns 3 and 5 outside the moving range of the movable coil 7. Therefore, both yokes 2 and 6 are downsized, and the voice coil motor has a good space factor.

It should be noted that in the above embodiment, the upper yoke 6 has three columns 3, 4,
Although it is supported by 5, if necessary, four or more struts may be provided, and in that case as well, by arranging the attraction center of the permanent magnet inside the polygon with each strut as the apex, a pair of top and bottom It is possible to easily and surely connect the yokes.

Further, in the above embodiment, the tip end surface of the column 4 is brought into contact with the permanent magnet 1. However, in addition to this, the tip end surface of the column is attached to the surface of the yoke exposed by dividing the permanent magnet or opening holes. May be abutted.

〔The invention's effect〕

As described above, in the voice coil motor according to the present invention, it suffices to dispose at least two columns outside the moving range of the movable coil, which allows the yoke to be downsized and the space factor to be improved. As a result, there is an effect that the magnetic disk drive device can be downsized, and since both yokes can be connected easily and surely, good assembly can be expected even if the size is reduced.

[Brief description of the drawings]

1 to 4 are for explaining a voice coil motor according to an embodiment of the present invention. FIG. 1 is a partial cross-sectional side view showing a structure of a pair of upper and lower yokes, and FIG. FIG. 3 is a plan view of the side yoke, FIG. 3 is a plan view of the upper yoke, FIG. 4 is a plan view showing a positional relationship between the movable coil and the yoke, and FIG. 5 is an inside of a magnetic disk drive device incorporating the voice coil motor. It is a top view which shows a structure. 1 ... Permanent magnet, 2 ... Lower yoke, 3,4,5 ... Posts,
7-moving coil, 7a-air core, 9-voice coil motor, 10-magnetic disk drive, 11-chassis, 13-hard disk, 14-magnetic head, 17-
Swing arm.

Claims (4)

(57) [Claims] 1. A movable coil attached to the other end of a support member having a magnetic head attached to one end thereof is movably provided between a pair of upper and lower yokes via a flat permanent magnet, In a voice coil motor of a magnetic disk drive device for controlling the energization of a movable coil to move the movable coil along the permanent magnet to swing the support member, the one yoke is placed on the other yoke. The attraction center of the permanent magnet is arranged inside a polygon having a plurality of supporting columns as vertices, and the tips of the columns are brought into contact with each other. A voice coil motor for a magnetic disk drive, which is fixed on the yoke of the. 2. A voice coil motor for a magnetic disk drive device according to claim 1, wherein the column is mounted on the permanent magnet. 3. A movable coil attached to the other end of a supporting member having a magnetic head attached to one end thereof is movably provided between a pair of upper and lower yokes via a flat permanent magnet, In a voice coil motor of a magnetic disk drive device for controlling the energization of a movable coil to move the movable coil along the permanent magnet to swing the support member, the one yoke is placed on the other yoke. A voice coil motor for a magnetic disk drive, wherein at least one of a plurality of supporting columns is arranged in the air core of the movable coil. 4. The magnetic disk drive device according to claim 3, wherein the support column arranged in the air core portion of the movable coil also serves as a stopper for restricting a moving range of the movable coil. Voice coil motor.