JPH05182443A - Method for suppressing attraction of magnetic head to magnetic disk device - Google Patents

Abstract

PURPOSE:To suppress the attraction of a magnetic head to a magnetic disk by the influence of corrosive gases by mounting a corrosive gas adsorbent and dehumidifier into the air flow route in a metallic container. CONSTITUTION:The corrosive gas adsorbent 6 or the adsorbent 6 and the dehumidifier 7 are mounted in a filter device 5, etc., of the air passage for the air passing between the disk 3 in the metallic container 1 forming the magnetic disk device and a head in the metallic container. Accordingly, the attraction of the magnetic head to the magnetic disk by the diffusion of the corrosive gases and moisture is suppressed and the reliability of operations is enhanced; in addition, the device life is prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk apparatus for reading / writing information by a magnetic head seeking on a rotating magnetic disk in a radial direction, and more particularly to a magnetic disk (hereinafter abbreviated as disk). And a magnetic head attracting method provided with means for preventing attraction of a magnetic head (hereinafter abbreviated as head).

[0002]

2. Description of the Related Art Generally, a magnetic disk device has a disk as an information recording medium and a head for reading and writing information as main components, and a spindle and a head for rotating the disk in a disk radial direction. And at least a drive device for seeking to
It has a structure in which these parts are hermetically sealed in a metal container.

In some cases, there is a structure in which a hole (breathing hole) of about several millimeters is provided in a metal case so that it is slightly communicated with the outside air, rather than being completely sealed.

In the magnetic disk device having the above structure, information is read and written by the relative movement of the head and the disk. At this time, if the force of attraction between the head and the disk, that is, the attraction force exceeds the torque of the spindle. So-called “head adsorption” (hereinafter abbreviated as “adsorption”) occurs, and reading and writing of information becomes impossible.

This adsorption is caused mainly by the fact that the lubricant applied to the surface of the disk is too thick, but in addition to that, it is caused by various gases released into the air from the inside of the device and gases in the atmosphere. It is also known to become.

Among such gases, corrosive gas has a great influence on adsorption. Nitrogen dioxide, sulfur dioxide, etc., for example, cause a chemical reaction with the moisture content of the moisture to generate nitric acid and sulfurous acid, respectively, which corrode the disc,
This corrosion product promotes adsorption.

[0007]

Despite the above-mentioned problems, the conventional disk device has not been protected against corrosive gas. Therefore, the reliability of the disk device is significantly impaired by the adsorption due to the corrosive gas.

The present invention has been made under such a background, and an object thereof is to provide a magnetic disk device having a structure capable of protecting against corrosive gas.

Another object of the present invention is to provide a method for suppressing magnetic head attraction.

[0010]

A magnetic disk device of the present invention comprises at least a disk and a head that move relative to each other in a container, and these disks and the head are adsorbed by the combination of corrosive gas and moisture in the air. In this case, at least one of a corrosive gas adsorbent and a dehumidifying agent is attached to the air circulation path inside the container.

The corrosive gas adsorbent is specifically a chemical adsorbent that adsorbs an acidic gas or an alkaline gas, and either one or both of them is provided in the apparatus.

Further, the method of the present invention is a method for suppressing adsorption of a magnetic head in a magnetic disk device having at least a head and a disk which move relative to each other in a container, and comprises a corrosive gas adsorbent and a dehumidifying agent. At least one of them is attached to the air circulation path inside the container, and at least one of the amount of corrosive gas and the amount of water in the container is suppressed before the contact between the disk and the head.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional structural view of a fixed disk device according to an embodiment of the present invention. 1 is a metal container, 2 is a spindle, 3 is a disk, 4 is a drive device, 5 is a filter device,
6 is a corrosive gas adsorbent, and 7 is a dehumidifying agent.

Although not shown, the disk 3
Heads that move relative to each other are provided near the surface of the disk, and information is read and written by seeking in the radial direction of the disk.

In the fixed disk device of this embodiment, the corrosive gas adsorbent 6 and the dehumidifying agent 7 are mounted inside the metal container 1 and at the flow passage of the air passing between the disk 3 and the head. It is characterized by As shown in FIG. 1, the mounting portion is, for example, the inside of the filter device 5 for inflow and outflow of outside air and the vicinity of the disk 3. The combination and quantity of both 6 and 7 are arbitrary, and only one of them may be used.

First, the corrosive gas adsorbent 6 and the dehumidifying agent 7 will be described. It is considered that the corrosive gas in the general atmosphere can be roughly classified into acidic gas and alkaline gas. Carbonate is suitable as an adsorbent for chemisorbing an acidic gas, while ammonia is assumed as an alkaline gas, so calcium chloride is suitable for chemisorbing this. Therefore, at least one or both of these adsorbents are combined to form the corrosive gas adsorbent 6.

The dehumidifying agent 7 is a general-purpose dehumidifying agent that removes moisture due to humidity (for example, trade name "silica gel").
To use.

In this embodiment, at least one of the corrosive gas adsorbent 6 and the dehumidifying agent 7 was mounted inside a fixed disk device and a reliability test was conducted.

Table 1 is a table showing combinations of the corrosive gas adsorbent 6 and the dehumidifying agent 7. In this embodiment, five levels will be introduced. The humidity in the device when the dehumidifying agent 6 was not used was 50%, and the amount of each chemical was 100% in the device.
It was used at a rate of 1 [g] per [ml].

[0021]

[Table 1]

Next, the reliability test method will be described. According to Japanese environmental standards, nitrogen dioxide contained in the atmosphere is 0.06 [ppm] and sulfur dioxide is 0.04 [ppm].
Up to is allowed.

Therefore, the test environment is set to 10 times the environmental standard, nitrogen dioxide 0.6 [ppm], and sulfur dioxide 0.4 [pp]
m], and ammonia was also a mixed atmosphere containing 0.5 [ppm] of the same level. The humidity of the mixed atmosphere was 50 [%], and the temperature at this time was 30 [° C].

The test was carried out by using a CSS test and a seek test together. Here, the CSS test is to stop the relative motion of the head and the disk 3 by turning off the power supply of the device (not shown), and the seek test is to move the head and the disk 3 relative to each other while the head is moved to the outer periphery of the disk 3. And the inner circumference are repeatedly moved in the radial direction of the disk.

Specifically, seek for 5 minutes (repeated movement in the radial direction about 2000 times) and one CSS are repeated. Since CSS cannot be performed when adsorption occurs in the device, it is possible to know how many times this repeated cycle has been endured. In other words, the environment resistance test can be performed by measuring the number of test cycles until CSS cannot be performed.

The test used three devices for each level to ensure the reliability of the results. Table 2 shows the test results.

[0027]

[Table 2]

According to the data in Table 2, in the mixed atmosphere used in the test environment, when neither the gas adsorbent 6 nor the dehumidifying agent 7 was installed (first level), all three adsorbed immediately after the test. It can be seen that the apparatus equipped with either the acidic gas adsorbent or the alkaline gas adsorbent and the dehumidifying agent 7 has a large number of operable times. Furthermore, the devices equipped with all three of them continued to operate without adsorption even after 500000 test cycles.

As described above, by suppressing at least one of the amount of corrosive gas and the amount of water in the metal container 1 before the contact between the disk 3 and the head, head adsorption is suppressed and the life of the apparatus is remarkably extended. It was proven to be effective.

Although the fixed disk device has been described in this embodiment, it is needless to say that the present invention can be applied to other magnetic disk devices such as a flexible disk device.

[0031]

As described above, in the magnetic disk device of the present invention, at least one of a corrosive gas adsorbent that adsorbs an acidic gas or an alkaline gas and a dehumidifying agent is mounted in the vicinity of the adsorption site of the disk and the head. However, since the corrosive gas and the moisture in the container are absorbed, head adsorption is suppressed, the operation reliability is remarkably improved, and the life of the device can be extended as compared with the conventional case.

Further, in the magnetic head adsorption suppressing method of the present invention, at least one of the corrosive gas adsorbent and the dehumidifying agent is mounted inside the container, and the corrosive gas amount and the water content in the container are contacted before the contact between the disk and the head. Since at least one of the amount and the amount is suppressed, the head adsorption can be suppressed by a simple means, the operation reliability can be improved, and the device life can be extended.

[Brief description of drawings]

FIG. 1 is a sectional structural view of a fixed disk device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Metal Container 2 Spindle 3 Magnetic Disk 4 Drive Device 5 Filter Device 6 Corrosive Gas Adsorbent 7 Dehumidifier

Claims (3)

[Claims] 1. A container comprising at least a magnetic disk and a magnetic head that move relative to each other in a container, wherein the magnetic disk and the magnetic head cause adsorption by the combination of corrosive gas and moisture in the air. At least one of a corrosive gas adsorbent and a dehumidifying agent is mounted on the air circulation path of the magnetic disk device. 2. The magnetic disk drive according to claim 1, wherein the corrosive gas adsorbent is a chemical adsorbent that adsorbs at least one of an acidic gas and an alkaline gas. 3. A method for suppressing magnetic head adsorption of a magnetic disk device comprising at least a magnetic head and a magnetic disk that move relative to each other in a container, wherein at least one of a corrosive gas adsorbent and a dehumidifying agent is used. Attached to an air circulation path inside the container, and suppressing at least one of the amount of corrosive gas and the amount of water in the container before the magnetic disk and the head come into contact with each other. Suppression method.