JPH03254480A - Head positioning device for magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent a lock magnet from being in contact with other member when a swing arm is locked by providing a lock magnet causing an attracting force or a repulsion force with a magnet of a magnetic circuit being a component of a swing arm driver onto a lock arm. CONSTITUTION:A lock driver 21 is provided with a lock arm 24, a lock shaft 22 supporting the lock arm 24, a bearing 23 and a lock magnet 23 provided onto the lock arm 24, and the lock magnet 25 is provided at a position attracting or repulsing a magnet 26 of a magnetic circuit when a swing arm 31 is moved to the lock position. The locking force is caused by, e.g., an attracting force between the lock magnet 25 and the magnet 26 of the magnetic circuit and since the magnetic flux density distribution gets higher in the center of the magnet 26 of the magnetic circuit, the lock magnet 25 is attracted in a direction of the arrow. Thus, the lock force is generated not in contact with other member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a head positioning device for a magnetic disk device, and particularly to a head positioning device for a swing arm type magnetic disk device.

[Conventional technology]

Among head positioning devices that are equipped with at least one magnetic head and perform positioning operations for recording and reproducing digital data on a magnetic disk provided in a magnetic disk device, conventional swing arm type head positioning devices are used. As shown in FIG. 3, the head positioning device includes a swing arm drive device (consisting of a coil 7 and a magnetic circuit 9) to keep the swing arm 11 fixed when the magnetic disk drive is not operating. The lock drive device 1 has a lock drive device 1 which is a drive device of a separate system, and is provided with two independent drive force generation sources. In addition, swing arm 11
A lock magnet 5 is provided as a means for fixing the swing arm 11, and the swing arm 11 is fixed by attracting a metal plate 12 to the lock magnet 5. In order to prevent dust generated by contact between the lock magnet 5 and the metal plate 12, a cover 13 is provided for sealing.

[Problem to be solved by the invention]

As mentioned above, conventional swing arm type head positioning devices require
The swing arm is fixed or released by supplying or cutting off current to a lock drive device that is a drive device in a separate system from the swing arm drive device.

In addition, as a means to keep the swing arm fixed, the force of the metal plate being attracted to the lock magnet is used.
During the locking operation, there is a risk of magnetic powder being scattered due to impact force being applied to the lock magnet, so it is necessary to seal the lock magnet and the metal plate.

[Means to solve the problem]

A head positioning device for a magnetic disk device according to the present invention includes a swing that carries at least one magnetic head for recording and reproducing digital data on a magnetic disk provided in the magnetic disk device and performs a positioning operation thereof. An arm-type head positioning device includes a swing arm driven by a swing arm drive device formed by a coil and a magnetic circuit having a magnetic circuit magnet, and the swing arm that moves to a specific position when the magnetic disk device is not operating. The lock driving device has a lock arm, a lock shaft and bearing that supports the lock arm, and a lock magnet provided on the lock arm, and the lock driving device drives the swing arm. The magnet is provided at a position where the magnetic circuit magnet attracts or repels the magnetic circuit magnet when the magnet is moved to the lock position.

〔Example〕

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

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
FIG. 3 is a sectional view showing a portion of the magnetic circuit of the illustrated embodiment.

In FIGS. 1 and 2, the swing arm 31 and the coil 27 are supported so as to be rotatable about a rotation center 30 of the swing arm 31. As shown in FIGS. A coil 27 and two magnetic circuits each having a magnetic circuit magnet 26 are arranged in a positional relationship that allows the swing arm 31 to operate efficiently.

The coil 27 is fixed at a predetermined position by a stopper 28 provided on the magnetic circuit 29 and a lock arm 24 having a lock magnet 25 except when the magnetic disk drive is in use. The lock arm 24 is fixed to the shaft 22, and the shaft 22 is connected to the lock drive device 1 via a bearing 23.
It is attached to 21. Lock drive system? ! ! The swing arm is locked (fixed) or unlocked (opened) by applying or stopping current to 21.

As shown in FIG. 2, the locking force is due to the attractive force or repulsive force between the lock magnet 25 and the magnetic circuit magnet 26.
Since the magnetic flux density distribution is high at the center of the magnetic circuit magnet 26, the lock magnet 25 is pulled in the direction of the arrow in FIG. 2 and generates a locking force without contacting other members.

〔Effect of the invention〕

As explained above, the head positioning device for a magnetic disk drive of the present invention includes a lock magnet that generates an attractive force or a repulsive force on the lock arm with the magnet of the magnetic circuit that constitutes the swing arm drive device. When locking the swing arm, the lock magnet that generates the locking force can be prevented from coming into contact with other members.
This has the effect of preventing the lock magnet from receiving direct impact force, eliminating the risk of magnetic powder scattering from the lock magnet, eliminating the need for a cover and sealing, and reducing the number of parts. The effect is that it can be done.

It is a side view showing an example of a positioning device.

1・21・・・Lock drive device, 5・25・・・
... Lock magnet, 7.27 ... Coil, 9.
29...Magnetic circuit, 11.31...Swing arm, 12...Metal plate, 13...
...Cover, 22...Shaft, 23...
...Bearing, 24...Lock arm, 26...
... Magnetic circuit magnet, 28 ... Stopper 30
······Rotation center······

Claims (1)

[Scope of Claims] 1. A swing arm type head that is equipped with at least one magnetic head for recording and reproducing digital data on a magnetic disk provided in a magnetic disk device and performs positioning operations thereof. In the positioning device, a swing arm driven by a swing arm drive device formed by a coil and a magnetic circuit having a magnetic circuit magnet, and a lock that drives the swing arm to move to a specific position when the magnetic disk device is not in operation. The lock driving device includes a lock arm, a lock shaft and a bearing that support the lock arm, and a lock magnet provided on the lock arm, and the lock magnet moves the swing arm to a locked position. 1. A head positioning device for a magnetic disk drive, characterized in that the head positioning device for a magnetic disk drive is provided at a position where the magnetic circuit magnet attracts or repels the magnetic circuit magnet when the head moves toward the magnetic disk drive. 2. In a swing arm type head positioning device that is equipped with at least one magnetic head for recording and reproducing digital data on a magnetic disk provided in a magnetic disk device and performs positioning operations, a coil and a A swing arm driven by a swing arm drive device formed by a magnetic circuit having a magnetic circuit magnet, and a lock drive device that drives the swing arm to move to a specific position when the magnetic disk device is not in operation, The lock driving device includes a lock arm, a lock shaft and a bearing that support the lock arm, and a lock magnet provided on the lock arm, and the lock magnet is configured to move the lock magnet when the swing arm is moved to the lock position. A head positioning device for a magnetic disk drive, characterized in that a magnetic circuit magnet is provided at a position where the magnetic flux density distribution is high.