JPH0963244A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a magnetic disk device with high impact resistance and high reliability by making a gap between required constitution parts of a magnetic disk device a specified value. SOLUTION: The gap between a head assembly body 32 formed by a slider 1 and a suspension 24 and a housing 6, and the gap between the respective assembly bodies of the slider 1 and the suspension 24 are limited to 0.4mm or below. Then, a moving distance of the slider by impact is limited remarkably small, and a collision speed does not exceed the value of damaging a disk medium, and the impact resistance is enhanced, and the magnetic disk device with the high reliability is constructed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a highly reliable magnetic disk device in consideration of impact resistance.

[0002]

2. Description of the Related Art A magnetic disk device has a storage density and a capacity increasing year by year, and its application is expected to be used not only in a conventional large-sized recording device and a recording device for a personal computer but also in a wide field.
For example, a type of mobile computing in which each person records necessary data and carries it around is being considered.

However, if an individual carries it around,
From the viewpoint of ease of use, improving the shock resistance of magnetic disk devices is an essential technology. For example, when the magnetic disk device is inserted into a PC card slot provided on the side surface of a personal computer or the like and used, a large impact resistance is not required. However, the magnetic disk device may drop from the desk when it is taken out of the PC card slot and brought (when not in operation). In order to withstand this, it is said that an impact resistance specification of at least 1000 G is required. Here, the PC card is a PCMCIA (Personal Compute
r Memory Card Internatial Association) / JEIDA
(Japan Electronic Industry Development Association)
Card type IC memory, magnetic disk device, which is used by being inserted into a slot conforming to the specifications of
Refers to other card-type electronic devices.

Various mechanisms have been devised to achieve improved impact resistance. For example, in Japanese Patent Laid-Open No. 4-368690, dampers made of rubber are provided at four corners of the magnetic disk device to reduce impact force and improve impact resistance.

The mode in which the data destruction of the magnetic disk device occurs due to the impact force is that the slider hits the magnetic disk and the recording magnetic layer of the magnetic disk is damaged.
The pressing load is constantly applied to the slider, but when the force acting on the slider due to the impact force becomes larger than the pressing load, the slider separates from the magnetic disk and re-collides.

The impact resistance of the magnetic disk due to the collision of the slider is reported in the following document. (1) "Experimental study on head / disk interface for impact resistance (1st report: Head /
"Mechanism of disk interface)", Naohiko Ishimaru, Japan Society of Mechanical Engineers (No.930-61) 1993 Information / Intelligent / Precision Equipment Division Lecture Proceedings P13-16 (2) "Head / disk interface experiments on impact resistance" Research (2nd Report, Effect of Substrate Material on Impact Resistance) ", Naohiko Ishimaru, Japan Society of Mechanical Engineers (No.930-6)
1) Proceedings of the 1993 Information / Intelligent / Precision Equipment Division Conference P
17 ~ 20 (3) `` Magnetic-Readback-Mapping and its Applicatio
n to Slider / Disk Damage due to Shock Impact '', ERH
ARD SCHRECK, Presented as a Society of Tribologist
s and Lubrication Engineers Paper at the ASME / STLE
Tribology Conference in Lahaina, Hawaii, October 16
-20,1994 According to these documents, the impact resistance can be greatly improved by using a material having a high hardness such as glass for the magnetic disk substrate. In reference (3), the slider is dropped from a certain height on the magnetic disk, and the limit collision speed at which magnetic disk damage occurs is determined experimentally.

[0007]

[Patent Document 1] Japanese Patent Application Laid-Open No. 4-36869
In No. 0, relaxation of impact force is considered, but damage to the magnetic disk by the slider is not considered.

Further, in the literature, there is no suggestion of what kind of structure should be used for a magnetic disk device using a magnetic disk having a high hardness such as glass.

An object of the present invention is to provide a structure of a magnetic disk device having high impact resistance and high reliability.

[0010]

In order to achieve the above object, the following structure is used in a magnetic disk device. First, a magnetic disk medium having a high hardness such as glass is adopted. When the magnetic disk device has one magnetic disk medium (hereinafter referred to as a single disk), the gap between the slider and suspension assembly and the housing and the gap between the slider and suspension assembly and the cover are about 0. 4m
Limit to m or less.

When the magnetic disk device has two magnetic disk media (hereinafter referred to as two circular plates), a gap between the slider / suspension assembly and the housing, and a gap between the slider / suspension assembly and the cover. ,
Gap 3 between the slider and suspension assembly
3 is limited to about 0.4 mm or less.

[0012]

The gap between the slider / suspension assembly and the housing, the gap between the slider / suspension assembly and the cover, and the gap 33 between the slider / suspension assembly are limited to about 0.4 mm or less. As a result, the moving distance of the slider due to the impact is limited, so that the collision speed of the slider with respect to the magnetic disk is not higher than the value at which the magnetic disk medium is damaged. As a result, impact resistance is dramatically improved.

As described above, the shock resistance of the magnetic disk device is improved, and high reliability can be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.
FIG. 1 shows an embodiment of the present invention. Here, a rotary type actuator 10 that causes the carriage 3 to swing is adopted. The slider 1 on which a magnetic head (not shown) for writing and reading information to and from the magnetic disk medium 11 is mounted, the suspension 24 for supporting the slider 1, and the carriage 3 to which the coil 2 is attached are the actuator bearing 4 and the actuator bearing 4. It is supported by the housing 6 via the pivot shaft 5.

The actuator 10 obtains a driving force by an electromagnetic action of a magnetic circuit composed of a magnet 7 and a yoke 8 supported by the housing 6. Actuator 10
Is the magnetic disk medium 11 rotating at a predetermined rotation speed.
The magnetic head is moved to the desired radial position above at high speed for positioning.

The magnetic disk medium 11 includes a spindle 12
It is fixed to the hub 13 by a disk clamp 14. Further, the magnetic disk medium 11 is the spindle bearing 1
It is supported by the housing 6 via 5 and the spindle shaft 16. Magnet rotor 1 mounted on hub 13
7 and the electromagnetic action of the coil stator 18 mounted on the housing 6, the spindle motor 19 obtains a driving force to rotate the magnetic disk medium 11. Cover 26
Keeps airtightness together with the housing 6. The above configuration is the HDA 20. Here, HDA means Head Disk
Abbreviation for Assembly.

On the other hand, the electronic component 21 for controlling the HDA 20 and the substrate 22 constitute a package 23, and the package 23 and the HDA 2 are connected by a connector or screws (not shown).
0 is integrated and housed in a case 27 in which a PCMCIA connector 25 is mounted, and constitutes a magnetic disk device.

In such a magnetic disk device, a gap 32 between the head assembly 28 consisting of the slider 1 and the suspension 24 and the housing 6 and a gap 31 between the head assembly 28 and the cover 26 are about 0.
It was 4 mm or less. As a result, as shown in FIG. 2, the collision acceleration during non-operation can be reduced to 1000 G or less. That is, when a unit impact force (F / m) is applied such that the half cycle of the sine wave is 1 msec, the acceleration of the slider 1 having the magnetic head mounted on the magnetic disk medium 11 is 1
It can be less than 000G.

By providing such a gap, it is possible to manufacture a magnetic disk device which is easy to use and has high reliability. Here, the non-operation means the spindle motor 19
When is not rotating. In a magnetic disk device that does not adopt the load / unload mechanism of the slider 1,
In most cases, the slider 1 is stopped at the innermost position of the magnetic disk medium 11 by a lock mechanism (not shown) provided in the actuator 10. The evaluation of FIG. 2 was also performed by stopping the slider 1 at the innermost position of the magnetic disk medium 11.

The evaluation conditions of FIG. 2 will be described in detail. The material of the substrate of the magnetic disk medium 11 is glass. 1.8 inch Ty with a nano slider mounted as slider 1.
The evaluation was performed by using a magnetic disk device in which pe3, two discs, and four magnetic heads were mounted. Here, the size of the nanoslider is a recommended dimension by IDEMA (abbreviation of International Disk Drive Association). A nanoslider made by the manufacturer according to these recommended dimensions was used.

The damage of the magnetic disk was judged to be no damage when there was no read error after applying a shock. The impact acceleration was measured at the housing position of the magnetic disk device using an impact tester. From FIG. 2, even if the impact acceleration of the housing 6 is 1000 G, the gaps 31 and 32 are about 0.4.
If it is less than or equal to mm, it is determined that the magnetic disk medium 11 is not damaged to the extent that an error occurs.

The impact resistance (collision resistance) is evaluated by such an experiment because the head assembly 28 is
Cover 26, housing 6, head assembly 28,
It was because we thought that we could get a near-true result only in the experiment because the mechanical elements collide several times and the movement of each machine element is complicated. Even if the substrate material of the magnetic disk medium 11 is glass ceramic or carbon having hardness equal to or higher than that of glass, similarly to the literature, high impact resistance can be obtained.

If the cover 26 and the housing 6 are used, the range in which the gap is limited to about 0.4 mm or less is not limited to the slider position on the innermost circumference of the magnetic disk medium 11,
The entire range in which the slider 1 moves can be covered. Therefore, even if the lock mechanism provided in the actuator 10 is disengaged due to the impact, and even if the slider 1 deviates from the innermost peripheral position of the magnetic disk medium 11 to the outer data recording area, the magnetic disk medium 11 is damaged. It is possible to improve the reliability of the magnetic disk device without giving

FIG. 3 shows another embodiment of the present invention. FIG. 3 shows a part of a magnetic disk device equipped with two discs and four magnetic heads. The gap 3 between the head assembly 28 of the slider 1 and the suspension 24 and the housing 6
2 and the gap 3 between the head assembly 28 and the cover 26
Not only 1 but also the gap between the head assemblies 28 is about 0.4.
It was less than or equal to mm. The effect of impact resistance is similar to that of the single disk magnetic disk device of FIG. The number of discs is 3
The same effect can be obtained even if the number of magnetic disk devices is one or more.

[0025]

According to the present invention, the gap between the head assembly 28, the housing 6, the cover 26, and the head assembly 28 is set to about 0.4 mm or less, thereby improving the shock resistance of the magnetic disk device. Reliability can be increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a magnetic disk device that is an embodiment of the present invention.

FIG. 2 is a graph of collision acceleration measured at a housing position by an impact tester.

FIG. 3 is a sectional view of a magnetic disk device according to another embodiment of the present invention.

[Explanation of symbols]

11: magnetic disk medium, 1: slider, 24: suspension, 28: head assembly, 32: gap between head assembly 28 and housing 6, 31: gap between head assembly 28 and cover 26, 33: head assembly The gap between three-dimensional comrades.

Front page continuation (72) Inventor Shun Matsuki 2880, Kokuzu, Odawara, Kanagawa Pref., Hitachi Storage Systems Division (72) Inventor Shigeyuki Hanazawa 2880, Kozu, Odawara, Kanagawa Hitachi, Ltd. Storage Systems Division

Claims (4)

[Claims] 1. A spindle on which a magnetic disk medium is mounted, a spindle motor which applies a rotational driving force to the spindle, a housing which rotatably supports the spindle through a bearing, and information writing to the magnetic disk medium. A magnetic head for performing a read operation; a slider for mounting the magnetic head; and a suspension connected to the slider for supporting the slider and for movably guiding the magnetic disk medium in a radial direction. An HDA comprising: a coil connected to the suspension; a magnetic circuit supported by the housing, which is paired with the coil to drive the slider; and a cover which is paired with the housing to maintain hermeticity, A magnet provided with a package consisting of an electronic component for controlling the HDA and a substrate. A disk device, wherein a magnetic disk medium made of glass or other high hardness material is mounted, and a gap between the slider / suspension assembly and the housing, a gap between the slider / suspension assembly and the cover are respectively provided. A magnetic disk device with a size of about 0.4 mm or less. 2. The magnetic disk device according to claim 1, wherein the gap between the slider and suspension assembly is about 0.4 mm or less. 3. The magnetic disk device according to claim 1 or 2, further having a size that conforms to a PC card standard. 4. The magnetic disk device according to claim 1 or 2, further comprising a magnetic disk device which can be inserted into a slot satisfying the standard of a PC card for use.