JPH05174528A - Device for restraining head of disk storage apparatus - Google Patents

Abstract

PURPOSE:To facilitate control of a restricting force by a method wherein a restrictor subjected to a magnetic farce is provided separately from a stopper and the magnetic force of the peripheral edge part of a magnetic field of a permanent magnet on the stator side of a voice coil motor is given to the restrictor while it is diffused appropriately. CONSTITUTION:A restrictor 50 is fitted to a fork-shaped end part 4c on the other side of a carriage 4 with a projection 4d interposed and it is positioned in the vicinity of the peripheral edge of a sectoral range of a permanent magnet 31. In other words, the peripheral edge of the restrictor 50 is made to accord with the peripheral edge of the magnet 31 while it is put in a restricted state. The restrictor 50 is made of a round wire of iron, steel or the like, ferrite and a permanent magnet material and the diameter thereof is made so small as to be about 1 to 2mm. As the restrictor 50 gets off from above the magnet 31, in this constitution, a magnetic field weakens and becomes a diffusive one, the sphere of action of a magnetic restricting force becomes narrow and nonuniformity does not occur. In other words, it becomes very easy to control a head 3 to be at a desired position inside a track zone TZ by a voice coil motor 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention restrains a head for reading and writing data in a prescribed restraining area in a disc surface when a disk storage device such as a fixed disc device in which a voice coil motor is operated is not used or when a power failure occurs. Head restraint device for.

[0002]

2. Description of the Related Art In a disk storage device, when the disk storage device is not used, particularly when it is used for a laptop computer, it is necessary to place the head in a restricted area so that the head will not hit the disk surface and damage the recording medium due to vibration or shock during movement. Is generally performed. FIG. 3 shows an example of a conventional restraint device for this purpose.

A disk storage device shown in FIG. 3 in a substantially actual size is a fixed disk device for incorporation in a laptop computer, and FIG. 3 (a) is an overall top view of the head restrained state, FIG. ) Is a partial top view of the released state. Case 10
The disk 1 housed inside is driven by an outer rotor type spindle motor 2. The head 3 for reading and writing data is supported by the end 4b of the carriage 4 via a leaf spring 3a. The carriage 4 is a swing arm pivotally supported by a rotary shaft 4a, and a fan-shaped voice coil, which is a mover 20 of a voice coil motor 40, is attached between a pair of fork-shaped ends 4c of the carriage arm. The stator 30 of the voice coil motor 40 includes a fan-shaped permanent magnet 31 and a plate-shaped yoke 32, and creates a magnetic field interlinking with the voice coil of the mover 20 in the front-back direction of the drawing.

The voice coil motor 40 controls the radial position of the head 3 on the disk 1, and a track zone in which a large number of tracks are set when data is read or written.
Although it is placed in TZ, when the disc storage device is not used, the disc 1 is usually restrained in a restraining area called a shipping zone SZ set on the inner diameter side as shown in FIG. 3 (a). In this conventional example, the restraint device 60 is a solenoid type electromagnet, and an engaging element 62 attached to the carriage 4 is engaged with the tip end of an operator 61 thereof to prevent the carriage 4 from rotating in a clockwise direction in the illustrated example. The head 3 is restrained in the restraint area SZ by. The engaging element 62 is, for example, a small leaf spring, and the spring force of the engaging element 62 restrains the carriage 4 from rotating with one of the fork-shaped ends 4c of the carriage 4 in contact with the stopper 34.

At the start of use of the disk storage device, the electromagnet of the restraint device 60 is urged to retract the operating element 61 as shown in FIG. 3B, and the engagement with the engaging element 62 is released to release the carriage 4. So that the head 3 can be moved to the track zone TZ. A stopper 35 is provided for the other fork-shaped end portion 4c of the carriage 4 so that the head 3 does not deviate to the outer diameter side from the track zone TZ. At the time of power failure or unexpected power failure after use of the device, the voice coil motor 40 is energized by using the counter electromotive force of the spindle motor 2 while the disk 1 is inertially rotating, and the head 3 is constrained to the restricted area SZ.
Move it inside and hold it in the restraint state shown in Fig. 3 (a).

In the disk storage device of FIG. 3 described above, the disk 1 is started with the head 3 in the restraint area SZ at the time of startup, so the head 3 is moved to the track zone TZ after aerodynamically levitating. At the time of stoppage or power failure, the head 3 first retracts from the track zone SZ to the restraint area SZ, and then the disk 1 stops, so that the head 3 does not come into contact with the disk surface in the track zone TZ and the recording medium is not damaged. Since the head 3 is restrained in the restraint area SZ by the restraint device 60 even when the apparatus is moved, there is no possibility of moving to the track zone TZ and damaging the recording medium.

[0007]

However, in the mechanical restraint device 60 as shown in FIG. 3, there is a problem that the restraint performance is likely to deteriorate during long-term use and the power consumption of the electromagnet cannot be ignored. That is, in the restraint device 60 of FIG. 3, since the operator 62 is mechanically engaged with the operator 62 to restrain the head 3,
When the restraint and release are repeated for a long period of time, the restraint performance gradually deteriorates due to the wear of the contact portion between the two and the restraint comes off even if a slight vibration or impact is applied. Also,
Due to the abrasion of the contact surface, dust is generated in the case 10 of the apparatus and adheres to the surface of the disk 1, and when the head 3 collides with this, the recording medium of the disk is likely to be damaged. In addition, since the restraint state of Fig. 3 (a) is maintained in the non-excited state of the electromagnet when the power is cut off or a power failure occurs, it is necessary to excite the electromagnet to put it in the released state of Fig. 3 (b) before use. Therefore, there is a problem that power consumption occurs during the usage time of the disk storage device, and the life of the battery is remarkably shortened especially when a laptop computer is used as a battery-powered portable type computer.

Therefore, a magnetic restraint device using a permanent magnet has been proposed in the past, for example, US Pat. No. 45.
In No. 94627, the permanent magnet incorporated in the mover of the voice coil motor is attracted to the magnetic stopper to restrain the head. Further, in Japanese Patent Publication No. 63-48110, the head is supported by attracting a magnetic stopper attached to a carriage supporting the head to the stator side by utilizing leakage flux of a permanent magnet on the stator side of the voice coil motor. to bound.

In such a magnetic restraint device, there is no problem of the above-mentioned power consumption and there is almost no deterioration in restraint performance. However, in any of the above techniques, the magnetic attraction force for restraint is made uniform when the disk storage device is mass-produced. It is not always easy to align them, and there is the problem that adjustment of binding force or quality control is troublesome. In other words, if the restraint force is too weak, the restraint becomes uncertain and it is easy to disengage when a shock is applied. Position operation becomes difficult. For this reason, it is necessary to manage the binding force within ± 20%, but the above-mentioned technology tends to cause a variation of about ± 50%.

An object of the present invention is to provide a head restraint device capable of uniformly controlling the restraining force while maintaining the advantages of the magnetic restraint described above.

[0011]

According to the present invention, as described above, a magnetic restrainer made of a ferromagnetic material or the like is provided in the restraining region for the carriage carrying the head and driven by the voice coil motor. The voice coil motor is attached so that it is located near the periphery of the magnetic field range by the permanent magnet on the stator side of the voice coil motor, and the head is restrained in the restraint area by the magnetic force acting from the stator magnetic field on this restraint. To achieve.

The restraint can be made of a permanent magnet as well as a ferromagnetic material. When the head is outside the restraint area, this restraint is outside the magnetic field range of the permanent magnet on the stator side of the voice coil motor, and when the head is inside the restraint area, the restraint is placed near the periphery of the magnetic field range. It is good to install. Further, it is advantageous to provide a stopper with which the carriage abuts when the head is in the restraint area and restrain the carriage while pressing it against the stopper by the magnetic force acting on the restraint. It is desirable to relax by means such as a buffer rubber. It is particularly advantageous to apply the restraint device of the present invention to the case where the carriage is a swing arm type and the voice coil motor is the fan-shaped structure described above.

[0013]

According to the present invention, when the magnetic force acting on the stopper made of a magnetic material is utilized as in the conventional magnetic restraint device described above, a large restraining force can be easily obtained, but the restraining force tends to vary. Paying attention to the above, a restraint that receives a magnetic force is provided separately from the stopper, and the magnetic gradient at the peripheral edge of the magnetic field by the permanent magnet on the stator side of the voice coil motor is set to a suitable level from the diffusive magnetic field. By applying a force, a restraint force with little variation among devices can be obtained without strict control of the attachment position of the restraint to the carriage.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (a) is a top view of a head storage state of a disk storage device corresponding to FIG. 3 to which the head restraint device according to the present invention is applied, FIG. 1 (b) is a sectional view in the vicinity of the voice coil motor, and FIG. ) And (b) are shown in Fig. 1 (a) and (b), respectively.
FIG. 3 is a top view of a disk storage device in a state where the head is released and a cross-sectional view near the voice coil motor corresponding to FIG. Since the same reference numerals are given to the portions corresponding to FIG. 3 in all of these figures, the description of the overlapping portions will be appropriately omitted.

In the restrained state of FIG. 1 (a), the head 3 is placed in the restraining area SZ which is the shipping zone on the inner diameter side of the disk 1, and the carriage 4 carrying it is the same swinging arm as in FIG. A pair of forked ends 4c
Mover 20 of voice coil motor 40 mounted between
The leads of the head 3 are led to the terminals 6 via the flexible multi-core connecting film 5. The stator 30 of the voice coil motor 40 has permanent magnets 31 and 1 as shown in the cross section of FIG. 1 (b).
Equipped with a pair of yokes 32 and 33, a pair of stoppers for both yokes 32 and 33
34 and 35 are used as columns to firmly bond to each other. The fan-shaped permanent magnet 31 fixed to the yoke 32 as shown in FIG. 1 (a) is composed of two portions 31a and 31b magnetized in opposite directions.
And these form an annular path of the magnetic field B between the yokes 32 and 33 as shown in the figure.

The fan-shaped mover 20 of the voice coil motor 40 or the voice coil is linked to the magnetic field B by the permanent magnet 31.
1 and one of the pair of fork-shaped end portions 4c of the carriage 4, which are inserted between the upper yoke 33 and the upper yoke 33, are in contact with the right stopper 34 in the restrained state of FIG. In order to reduce the impact at the time, the stopper 34 is integrally formed with a buffer means 36 such as synthetic rubber so as to surround it. A non-magnetic material such as aluminum is used for the carriage 4.

The restraint 50 constituting the restraint device of the present invention is
In the illustrated example, it is attached to the other fork-shaped end 4c of the carriage 4 via a protrusion 4d, and its position is the range of the magnetic field B in the restrained state shown in FIG. 1, that is, the sector-shaped range of the permanent magnet 31. The restrictor 50 is attached so that its peripheral edge coincides with the peripheral edge of the permanent magnet 31 in the constrained state in the illustrated example. The restraint 50 may be made of a magnetic material, for example, a very small restraint 50 having a diameter of about 1 to 2 mm using a ferromagnetic iron or steel round wire, a ferrite material, a permanent magnet material, or the like. Sufficient magnetic restraint force is obtained. Since the restraint member 50 is extremely lightweight in this manner, it can be attached by a very simple means such as resin bonding.

The strength of the magnetic field B is usually about several thousand gauss, and under this comparatively strong magnetic field B, a magnetic force is applied to the restraint 50 to the right in the figure, and the carriage 4 is stopped.
The head 3 is restrained while being pressed against the 34. In this restraint state, the magnetic field B is placed at the position where the restraint 50 is placed.
Is a diffusive magnetic field that weakens as it deviates from the top of the permanent magnet 31, and its lateral magnetic gradient is relatively gentle. Therefore, in the present invention, magnetic restraint is required even if the accuracy of the position of attaching the restraint 50 to the carriage 4 is not increased as in the conventional case. Forces can be managed within sufficiently narrow variations.

When the disk storage device is powered on in the state shown in FIG. 1, the disk 1 is first rotated to levitate the head 3 and then the voice coil motor 40 is energized to release the head 3. Move to track zone TZ.

This released state is shown in FIGS. 2 (a) and 2 (b). The head 3 is restricted by the bias of the voice coil motor 40.
When entering the track zone TZ from SZ, the restraint 50 is a permanent magnet.
Since it goes out of the range of the magnetic field due to 31, magnetic force does not act at all, and the voice coil motor 40 can freely control the head 3 to a desired position within the track zone TZ. A stopper 35 is provided so that the head 3 does not deviate to the outer diameter side of the track zone TZ. However, since the carriage 4 may occasionally collide with the stopper 35 immediately after the release, the impact at this time is softened and rebounded. Buffering means to prevent
36 is also provided on the stopper 35. When power supply is cut off after use of the disk storage device or when an unexpected power failure occurs, the voice coil motor is driven by the counter electromotive force of the spindle motor 2 while the disk 1 is still rotating as described above.
Energize 40 to move the head 3 from the track zone TZ to the restraining area.
Move it to SZ and set it in the restraint state shown in Fig. 1.

[0021]

As described above, in the head restraint device of the present invention, the head restrains the magnetic restrainer with respect to the carriage which carries the data read / write head and is attached with the mover of the voice coil motor for its operation. It is installed so that it is located near the periphery of the magnetic field range of the permanent magnet on the stator side of the voice coil motor only when it is in the area, and the head is restrained in the restraint area by the magnetic force that acts on the restraint from the stator magnetic field. The effect of can be improved.

(A) Since the magnetic gradient of the magnetic field at the peripheral edge of the magnetic field by the permanent magnets of the stator of the voice coil motor acts on the restraint from the appropriate diffusive magnetic field, the restraining magnetic force acts on the restrainer, so that mass production of disk storage devices is performed. At that time, it is possible to manage the variation of the binding force within each device within about ± 20% without particularly adjusting the mounting position of the binding element to the carriage. (b) The restraint may be a very small and inexpensive one, and it can be attached only to the carriage by, for example, resin or the like.
In addition to the fact that adjustment of binding force is unnecessary and quality control is easy, mass production costs of disk storage devices can be reduced. (c) Since the head is magnetically restrained by using a permanent magnet, the restraint performance does not deteriorate during long-term use of the disk storage device, and there is no power consumption unlike a mechanical restraint device. ..

[Brief description of drawings]

FIG. 1 shows a head restraint state of a disk storage device incorporating a head restraint device of the present invention, FIG. 1 (a) is a top view thereof, and FIG. 1 (b) is an enlarged sectional view near a voice coil motor. ..

2A and 2B show a head released state of a disk storage device equipped with the restraint device of FIG. 1, FIG. 2A being a top view thereof, and FIG.
FIG. 4 is an enlarged sectional view of the vicinity of a voice coil motor.

3A and 3B show a disk storage device in which a conventional mechanical restraint device is incorporated. FIG. 3A is an overall top view of the head restrained state, and FIG. 3B is a partial top view of the released state. ..

[Explanation of symbols]

 1 Disk 3 Head 4 Carriage 10 Disk Storage Case 20 Voice Coil Motor Mover 30 Voice Coil Motor Stator 31 Permanent Magnet 34 Stopper 36 Buffer Means 40 Voice Coil Motor 50 Restraint B Magnetic Field SZ Restraint Area or Shipping Zone

Claims (3)

[Claims] 1. A device for restraining a data read / write head whose position on the disc surface is operated by a voice coil motor in a predetermined restraining region in the disc surface, the device carrying the head and moving the voice coil motor. A magnetic restraint is attached to the carriage to which the child is attached so that it is located near the periphery of the magnetic field range by the permanent magnet on the stator side of the voice coil motor only when the head is in the restraint area.
A head restraint device for a disk storage device, characterized in that a head is restrained in a restraint region by a magnetic force acting on the restraint by a stator magnetic field. 2. The apparatus according to claim 1, further comprising a stopper with which the carriage abuts when the head is in a restraining area, and the head is restrained in a state where the carriage is pressed toward the stopper by a magnetic force acting on the restraint. A head restraint device for a disk storage device, comprising: 3. The disk storage device according to claim 1, further comprising a stopper with which the carriage collides when the head is operated toward the restraint area, and the collision is mitigated by the buffer means. Head restraint device.