JPS62244266A - Position mechanism of magnetic head - Google Patents

Abstract

PURPOSE:To remove leakage flux, and to obtain strong return force by continuing a magnetic circuit through which magnetic flux by a ring magnet passes. CONSTITUTION:When currents fed to a coil 3 are interrupted when a magnetic head is separated from a CSS zone, an N pole and an S pole for a ring magnet 21 are attraoted to an S pole and an N pole for a ring magnet 15, and arm groups 4a-4d are turned up to positions where they are mutually adjoined maximally, positions where the magnetic head reaches on the CSS zone of a magnetic disc. A high-power magnetic material can be used as the ring magnet 21 at that time, and a magnetic circuit through which magnetic flux passes is continued and there is no leakage flux, thus acquiring strong return force.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head positioning mechanism, and in particular to a so-called swing arm type voice coil motor that positions a magnetic head on an arbitrary track of a magnetic disk by rotational motion. The present invention relates to a positioning mechanism for a magnetic head using a magnetic head.

[Conventional technology]

In general, a magnetic disk drive has a plurality of magnetic disks stacked and mounted on one spindle, which is rotated steadily by a spindle motor, and is a positioning machine equipped with a magnetic head provided corresponding to the storage surface of the magnetic disk. S(
This is usually called a carriage or a positioner, but hereafter they are representatively called a positioner) and has a configuration that positions it on a designated track of a magnetic disk and writes and reads information.@Such a positioner In small magnetic disk drives that use magnetic disks with a diameter of about 13cIL, the operation is usually driven by a stepping motor, but the positioning operation by the stepping motor is controlled by open-loop control (control that does not use servo control based on feedback of positioning errors). Since the stepping angle is also approximately 0.9 degrees, it is impossible to increase the track density of the magnetic disk to a certain degree.

Therefore, in order to realize a device with high storage density even in a small magnetic disk device, it is necessary to use a voice coil motor and perform servo control to perform a positioning operation.

On the other hand, in order to improve the storage density of recent magnetic disk drives, when the magnetic disk is not rotating, the magnetic head comes into contact with the corresponding storage surface of the magnetic disk and stops, and as the magnetic disk rotates, the magnetic head stops. The so-called contact start-stop method is a method in which information is written and read while maintaining a certain distance between the disk and the storage surface of the magnetic disk by floating it using the airflow generated by rotation.
CSS method) is adopted. In such a C8S type magnetic disk device, a specific area (hereinafter referred to as C
8S zone) is provided outside (inner side or outer side) of the area where information is written and read (hereinafter referred to as R/W zone), and information writing and reading operations (hereinafter referred to as B/W operation) are provided outside (inner side or outer side) of the area where information is written and read. When this process is completed, the magnetic head is returned to the C8S zone, and then the rotation of the magnetic disk is stopped.

To execute such a return operation of the magnetic head to the C88 zone (hereinafter simply referred to as return operation), a program that causes the above return operation to be performed at the end of each business processing program of a system using a magnetic disk device is required. Therefore, conventionally, the above-mentioned matters are noted in the business processing program creation manual to encourage the person in charge of creating each business program to incorporate the return operation program. However, in reality, not all business processing program creators strictly adhere to the above precautions, and as a result, business processing programs that lack automatic magnetic head return programs may be executed. In this case, the rotation of the magnetic disk is stopped while the magnetic head remains on the 几/W zone, and the magnetic head comes into contact with the magnetic disk at the 几/W zone and stops, causing damage to the storage surface of the magnetic disk. So-called head crack S
) may occur. Further, the same phenomenon as described above occurs when the power supply to the magnetic disk device is stopped for some reason during the R/W operation. Furthermore, when transporting or moving a magnetic disk device, impact force is applied to the magnetic disk device, and this impact force can cause the magnetic head to move while in contact with the magnetic disk, causing scratches and damage to the storage surface. Sometimes I give.

In order to prevent damage to the magnetic disk due to such causes, an automatic return mechanism is installed that automatically returns to the C8S zone if the magnetic disk stops rotating while the magnetic head is on the R/W zone. You need to be prepared. For positioning using a voice coil motor, especially a so-called swing arm type voice coil motor that rotates and oscillates around a fixed rotating shaft, automatic return machine #IIFi as described above, large magnetic magnetic Some disk devices use a mechanism that uses a spiral spring to automatically return to its original position by its return force, but this method requires a considerable amount of space to mount the related parts, so It is difficult to provide this means in magnetic disk drives because the necessary space is not available.

In order to solve such problems, the invention of the present invention.

He invented a magnetic head positioning mechanism equipped with an automatic return mechanism as shown in the figure, and filed a patent application in 1986.
113503).

FIG. 2 is a plan view showing a main part of an embodiment of the invention of the above application.

Referring to FIG. 2, arms 4a to 4d each have a magnetic head 5 mounted on their tip (as shown in FIG. The rear portions of the arms (of which a plurality of arms are usually provided) are stacked and mounted on the arm holder 11 at predetermined intervals to form the arm group 4, and rotate as one around the rotation axis 6. be able to. At the rear of the arm group 4 (on the side opposite to the magnetic head 5 with respect to the rotating shaft 6), a single coil 3 is provided. A yoke is provided surrounding the top and bottom, left and right sides of the magnet, and a magnetic circuit is constituted by the permanent magnet 7 and the yoke. Therefore, by passing an appropriate current in the forward or reverse direction through the coil 3, the coil 3 rotates in the direction of the arrow IN or OUT, and the magnetic head 5 is positioned on a predetermined track on the magnetic disk 22.

3(a) and 3(b) are enlarged sectional views showing the details of the XX section in FIG. 2 and Y-Y in FIG. 3(a).
FIG.

As shown in FIG. 3, the arms 4a to 4d have holes provided in their rear parts that fit into the outer periphery of the hollow cylindrical part 11a of the arm holder 11, and spacer rings 12a to 12c.
The arm group 4 is stacked at a predetermined distance to form an integrated arm group 4.

The arm holder 11 is usually made of a lightweight material such as aluminum, and a hollow sleeve 1 made of carbon steel or stainless steel is installed inside the hollow cylindrical portion 11a.
3 is inserted. Arm holder 11 and sleeve 1
3 and 3 by a manufacturing method such as integrated casting, and are completely integrated within the operating temperature range of a normal magnetic disk device.

Pole bearings 16 and 17 are mounted inside the sleeve 13 at its upper and lower ends. The outer side of the outer ring of the lower ball bearing 17 is attached to the inner surface of the sleeve 13, and the inner side of the inner ring is fixed to the outer side of the rotating shaft 6 by adhesive. On the other hand, the inner ring of the upper pole bearing 16 is fixed to the rotating shaft, but there is a very small play between the outer ring and the sleeve 13, and the lower surface of the outer ring is constantly pressed upward by the compression spring 19. Is receiving. Such a configuration eliminates play between the balls of the ball bearings 16 and 17 and the inner and outer rings.

An annular iron piece holder 20 is fixed near the center of the inner surface of the sleeve 13, and its upper surface serves as a pedestal for supporting the lower surface of the compression spring 19. Iron piece holder 2
0 also has two notches at both ends of its arbitrary diameter, and these notches have a soft iron piece (or ferromagnetic piece or permanent magnet) with approximately the same thickness as the iron piece holder 20. , hereinafter referred to as iron pieces) 14 are firmly fixed.

A ring magnet 15 made of a permanent magnet is provided inside the iron piece holder 20 at a position corresponding to the iron piece 14. The inner surface of the ring magnet 15 is fixed to the rotating shaft 6. and the S pole correspond to the iron piece 14. The lower end of the rotating shaft 6 is fixed to a yoke 8 attached to the base plate 10, and the upper end thereof is screwed and fixed to the holding plate 2 via a fixing ring 18.

As described above, the operation of the magnetic head positioning mechanism configured as described above is such that the magnetic head 5 is positioned on a predetermined track of the magnetic disk 22 by passing an appropriate current through the coil 3. This positioning operation causes the iron piece holder 201 and therefore the iron piece 14 to rotate relative to the ring magnet 15, and the iron piece 14 is moved to a position away from the ON pole and S pole of the ring magnet 15. In this state, due to some reason, the coil 3
When the current supplied to the ring magnet 15 is cut off, the iron piece 14 is attracted toward the ON pole and the S pole of the ring magnet 15, so that the closest position, that is, the magnetic head 5 is connected to the magnetic disk 22.
Rotate the arm group 4 to a position above the C88 zone. (The iron piece 14 is a ring magnet) The relative positions of the iron piece 14 and the ring magnet 15 are determined so that when the iron piece 14 comes closest to the north and south poles of the iron piece 15, the magnetic head is on the C8S zone. ) As a result, no matter where the magnetic head is located on the magnetic disk, when the rotational movement of the magnetic disk stops, the magnetic head is always moved to C8S.
automatically returned to the zone.

As described above, the mechanism that automatically returns the magnetic head to the CSS zone using a ring magnet and a corresponding iron piece is an extremely effective mechanism, but the iron piece is held by an iron piece holder and attached to the inner surface of the sleeve. Because of this structure, the structure is complicated and assembly is not easy, and the structure also has the problem that it is difficult to obtain a sufficient return force due to leakage magnetic flux.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention, in other words, the purpose of the present invention is to improve the drawbacks of the conventional magnetic head positioning mechanism as described above, to provide a simple structure, easy assembly work, and
Another object of the present invention is to provide a positioning mechanism for a magnetic head that can increase the return force to ensure a return to the C8S zone.

[Means for solving problems]

The magnetic head positioning mechanism of the present invention includes a hollow arm holder on which at least one arm carrying a magnetic head that writes or outputs information to a magnetic disk is mounted, and a a hollow sleeve that is provided and operates integrally with the arm holder; a first ball bearing having an outer ring fixed inside one end of the sleeve; and one ball bearing fixed to the inner ring of the first ball bearing A rotating shaft having a fixed end, a second ball bearing having an inner ring fixed to the other end of the rotating shaft, and one end face of the second ball bearing contacting an end surface of an outer ring of the second ball bearing. a compression spring that presses the compression spring outward; a first permanent magnet that supports the other end surface of the compression spring and has at least a pair of annular magnetic poles fixed inside the sleeve; and a second annular permanent magnet fixed at a position corresponding to the first permanent magnet on the rotating shaft and having a magnetic pole at a position corresponding to the magnetic pole of the first permanent magnet.

〔Example〕

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

FIG. 1(a) is a cross-sectional view showing details of the main part of an embodiment of the present invention, and is a cross-sectional view corresponding to the XX cross-section in FIG. 2. FIG. 1(b) is a YY sectional view of FIG. 1(a).

The planar appearance of this embodiment is the same as that of the conventional positioning device shown in FIG. 2, but the parts constituting the automatic return mechanism installed inside the sleeve are different.

That is, as shown in FIGS. 1(a) and 1(b), the ring magnet 15 is fixed to the rotating shaft 6, which is the same as in the conventional example shown in FIG. A second ring magnet 21 is fixed to the inner surface of the sleeve 13. This ring magnet 21 is provided with a magnetic pole at a position corresponding to the magnetic pole of the ring magnet 15), and is mounted so that it takes a stable position when the magnetic head returns to the C8S zone. The structure of the parts other than those mentioned above is the same as the conventional example explained based on FIG. 3.

Therefore, in the case of this embodiment, as in the conventional example, if the current supplied to the coil 3 is cut off when the magnetic head is away from the C8S zone, the N of the ring magnet 21
The poles and S poles are the S and N poles of ring magnet) 15.
The arm group 4 is rotated to a position where the magnetic heads are attracted toward the pole and are closest to each other, that is, a position where the magnetic heads are on the C8S zone of the magnetic disk. At this time, a strong return force can be obtained because a strong magnetic material can be used as the ring magnet 21, and because the magnetic circuit through which the magnetic flux passes is continuous, there is no leakage magnetic flux. Also, ring i gne)
21 can be constructed from a single component, so the structure is simple and its assembly work is also easy.

Note that the ring magnet 15 and the corresponding ring magnet 21 can be configured to have two or more pairs of N-8 poles as necessary. [Effects of the Invention] As described above in detail. By using the magnetic head positioning mechanism of the present invention, if the rotation of the magnetic disk stops while the magnetic head is on the │/W zone of the magnetic disk, the magnetic head is automatically moved to the C゛SSSS zone, When preventing a so-called head crash, there is an effect that the operation can be performed reliably, and since the assembly can be performed easily, the manufacturing cost can be reduced. Therefore, it is possible to obtain a magnetic disk device having a low manufacturing cost and a highly reliable automatic return mechanism.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are a sectional view and a Y-Y sectional view showing details of the main parts of an embodiment of the present invention, and FIG. 2 is a plan view showing the configuration of a conventional magnetic head positioning mechanism. , FIG. 3(a) is a sectional view taken along line XX in FIG. 2, and FIG. 3 tb) is a sectional view taken along line YY in FIG. 3 ta+. 6...Rotation axis, 11...Arm holder, 13.°. ...Sleeve, 15...Ring magnet. \N--''yFJ1 Figure and 2: Handling presser foot 41 Rotating shaft 3: Coil 7; Suemata warehouse b4 Ni arm, 2
;;Ko f ff: “;12=-muho 2 leg!s;@Kihe 1.7 de 22-.2;
akiwan school fi2 diagram

Claims (1)

[Claims] A hollow arm holder on which at least one arm carrying a magnetic head for writing or reading information on a magnetic disk is mounted, and a hollow arm holder provided inside the arm holder and operating integrally with the arm holder. a first ball bearing having an outer ring fixed inside one end of the sleeve; and a rotating shaft having one end fixed to the inner ring of the first ball bearing;
a second ball bearing internally fixed to the other end of the rotating shaft; and a compression spring that contacts an end surface of an outer ring of the second ball bearing at one end surface thereof and presses the outer ring outward. , a first permanent magnet having at least a pair of annular magnetic poles that supports the other end surface of the compression spring and is fixed inside the sleeve; and the first permanent magnet on the rotating shaft. and a second annular permanent magnet fixed at a position corresponding to the magnetic pole of the first permanent magnet and having a magnetic pole at a position corresponding to the magnetic pole of the first permanent magnet.