JP3140288B2 - Magnetic disk drive respiratory filter assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a respiratory filter assembly for a magnetic disk drive. 2. Description of the Related Art In recent years, the size and thickness of magnetic disk devices, which are a type of external storage device for computers, have been reduced, and lower power consumption has been demanded. In addition, an increase in the recording density of a magnetic disk is required to increase the capacity, and the number of magnetic disks mounted on the apparatus is increasing.

[0002]

2. Description of the Related Art In a magnetic disk drive for a computer,
As for the relationship between the head and the magnetic disk, a contact start / stop (CSS) system is generally adopted. In this method, during rotation of the disk, the head floats above the magnetic disk with a small gap between the floating force of the air fluid generated by the high-speed rotation and the force of the spring arm pressing the head against the disk.

When the rotation of the magnetic disk stops, the head moves to a contactable area on the disk, where the head and the disk come into contact. While the disk stops rotating, the head and the disk remain in contact.

As described above, while the magnetic disk is rotating, the head floats on the disk with a small gap therebetween, so that a slight dust or the like causes a head crash or the like. For this reason, magnetic disks and actuator assemblies for writing / reading data to / from these magnetic disks are arranged in a closed chamber defined within a disk enclosure (housing).

[0005] However, it is difficult to maintain the hermetic seal inside the magnetic disk device for a long period of time, and the flying height of the magnetic head changes due to pressure fluctuation inside the device due to temperature change or the like. In order to prevent this, a minute ventilation hole is provided in the cover of the magnetic disk device so that the pressure inside the magnetic disk device is substantially equal to the external pressure.

[0006] A breathing filter is usually attached to the minute vent, and this breathing filter prevents dust from entering the inside from the outside of the apparatus. However, since a breathing filter generally used in the past passes water vapor, corrosive gas, and the like into a magnetic disk drive, U.S. Pat.
No. 1,594 discloses a technique in which a narrow and long air passage is formed to delay the invasion of water vapor into the inside of the device due to the diffusion of air.

Japanese Patent Application Laid-Open No. Sho 60-147983 discloses that
A technique has been disclosed in which a throttle and a desiccant are arranged in an air flow path to prevent water vapor from entering the inside of the device. Further, Japanese Patent Application Laid-Open No. 5-109260 discloses a technology for removing harmful gas molecules in a magnetic disk device by incorporating a filter assembly in which a nonwoven fabric, a metal-coated filter and activated carbon are combined in a magnetic disk device. ing.

[0008]

The corrosive gas contained in the air entering the magnetic disk drive oxidizes the disk surface and the magnetic head transducer, shortening the life of the disk and the magnetic head. It is known to place activated carbon in a magnetic disk drive to trap corrosive gases.

In a large magnetic disk drive such as an 8-inch or 5.25-inch magnetic disk drive, a sufficient amount of activated carbon and a desiccant can be arranged in the drive. Due to the limited space in magnetic disk drives, it is not possible to place a sufficient amount of activated carbon and / or desiccant in the drive. If the amount of activated carbon is small, the ability of the activated carbon to immediately absorb corrosive gas is lost, and the life of the activated carbon is shortened.

In the above-mentioned US Pat. No. 4,751,594, a narrow and long air passage is formed in order to prevent water vapor and corrosive gas from entering the inside of the apparatus. Then, the ventilation device becomes complicated and large. Further, merely forming a narrow and long air passage cannot prevent air from entering the inside of the device due to a pressure difference between the inside and the outside of the device.

Further, as disclosed in Japanese Patent Application Laid-Open No. 60-147983, a method of simply attaching a restrictor and a desiccant to a vent hole is not enough to reduce the diffusion of air. According to this method, the desiccant absorbs not only water vapor entering the magnetic disk device but also water vapor outside the magnetic disk device, and the life of the desiccant is shortened.

In order to extend the life of the desiccant, there is a method of increasing the amount of the desiccant. In particular, in the case of a small magnetic disk device, due to the space, a desiccant sufficient to satisfy the life of the device is provided in the magnetic disk device. It is impossible to place them.

As a technique which can be easily inferred from this publication, a method of attaching activated carbon to a vent can be considered. However, simply attaching activated carbon to a vent also shortens the life of activated carbon. Causes the corrosive gas to pass through the magnetic disk drive as it is.

The filter assembly disclosed in Japanese Patent Application Laid-Open No. 5-109260 is a filter for removing harmful gas circulating inside the magnetic disk drive, and is not a respiratory filter mounted on a vent.

In such a filter assembly, since the inside of the device and the outside of the device are connected by a vent,
Water vapor and corrosive gas from the outside of the device enter the inside of the device. In addition, since water vapor or corrosive gas once spreads inside the apparatus, it takes time to absorb water vapor or corrosive gas because it absorbs water vapor or corrosive gas, which adversely affects disks and heads.

Further, since the outside of the apparatus and the inside of the apparatus are connected by a vent, the filter assembly always absorbs water vapor and corrosive gas outside the apparatus, and the life is shortened. To extend the life, the size of the filter assembly needs to be increased.

It is therefore an object of the present invention to provide a respiratory filter assembly for a magnetic disk drive capable of adsorbing and removing corrosive gas for a long time with a small size and a simple structure.

[0018]

According to the present invention, there is provided a respiratory filter assembly for a magnetic disk drive including a base and a cover having a vent fixed to the base, the vent being in communication with the vent. A casing fixed to an inner surface of the cover, the casing being fixed to an inner surface of the cover, the casing being accommodated in the casing adjacent to the vent. A first filter made of a plurality of fibers arranged in a direction substantially parallel to an air flow direction from the ventilation inlet to the ventilation outlet; a second filter adhered to the casing so as to cover the ventilation outlet; A respiratory filter assembly for a magnetic disk drive, comprising: a first filter and a second carbon layer; an activated carbon layer housed inside the casing.

According to another aspect of the present invention, there is provided a respiratory filter assembly for a magnetic disk drive including a base and a cover having a vent fixed to the base, the vent filter including a vent communicating with the vent and a magnetic filter. A casing fixed to an inner surface of the cover, the casing having a ventilation outlet provided opposite to the ventilation inlet communicating with the inside of the disk device; and being housed in the casing adjacent to the ventilation inlet.
A first filter comprising a plurality of fibers arranged in a direction parallel to an air flow direction from the ventilation inlet to the ventilation outlet; a filter housed in the casing adjacent to the ventilation outlet and containing activated carbon therein A respiratory filter assembly for a magnetic disk drive comprising a bag.

[0020]

The fibrous first filter reduces the effect of air diffusion in a narrow space and prolongs the life of activated carbon. This makes it possible to adsorb and remove the corrosive gas entering the inside of the magnetic disk device with activated carbon for a long period of time.

When there is a pressure difference between the inside and the outside of the magnetic disk drive, a large pressure loss occurs due to the passage of air through the fibrous first filter, so that the inflow and outflow of air through the ventilation port is moderate. , It is possible to extend the life of the activated carbon.

Thus, the corrosive gas entering the magnetic disk drive can be adsorbed and removed with activated carbon for a long period of time, so that a small amount of activated carbon is used and the installation space for the respiratory filter assembly is small. I'm done.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. Referring to FIG. 1, there is shown a plan view of a magnetic disk drive equipped with the respiratory filter assembly of the present invention. Referring also to FIG. 2, reference numeral 12 denotes a housing (enclosure) including a base 14 and a cover 16. A spindle hub 1 that is rotated and driven by an inner hub motor (not shown) on a base 14
8 are provided.

The spindle hub 18 has a magnetic disk 20
And a space (not shown) are alternately inserted, and a plurality of magnetic disks 20 are attached to the spindle hub 18 at predetermined intervals.

Reference numeral 22 denotes a rotary actuator assembly comprising an actuator arm assembly 26 and a magnetic circuit 28. The actuator arm assembly 26 is rotatably mounted around a shaft 24 fixed to the base 14, and has an actuator arm 30 extending in one direction from the center of rotation. A spring arm 32 supporting a magnetic head 34 is fixed to the tip of the actuator arm 30.

Reference numeral 36 denotes a flexible printed wiring sheet for extracting a signal from the magnetic head 34.
One end is fixed to the actuator arm 30 and the other end is connected to the connector 38.

An annular packing assembly 40 is mounted on the base 14, and the housing 12 is sealed by screwing the cover 16 to the base 14 with the packing assembly 40 interposed therebetween as shown in FIG. You.

Referring to FIG. 2, there is shown a sectional view of the housing of the magnetic disk drive taken along the section of the respiratory filter assembly. In this sectional view, only the respiratory filter assembly 42 and the housing 12 of the first embodiment are shown, and the magnetic disk 20, the actuator assembly 22, and the like are omitted.

A vent 16a is formed in the cover 16, and a respiratory filter assembly 42 having a vent 44a communicating with the vent 16a is adhered to the inner surface of the cover 16 with a double-sided adhesive tape.

Referring to FIGS. 3 and 4, the structure of the respiratory filter assembly 42 will be described in detail. The casing 44 of the breathing filter assembly 42 has a ventilation inlet 44a communicating with the ventilation opening 16a of the cover 16 and a ventilation outlet 44b communicating with the inside of the magnetic disk drive.

The ventilation inlet 44a and the ventilation outlet 44b are formed on opposing wall surfaces of the casing 44. A double-sided adhesive tape 58 defining an air passage 60 is attached to the upper surface of the casing 44, and the breathing filter assembly 42 is adhered to the inner surface of the cover 16 by the double-sided adhesive tape 58.

The respiratory filter assembly 42 includes the cover 16
Is adhered to a predetermined position of the cover 16, the vent 16a of the cover 16
The casing 44 communicates with the ventilation inlet 44 a through an air passage 60.

The double-sided adhesive tape 60 has elasticity,
The inside of the magnetic disk device is sealed by the double-sided adhesive tape 60, and the inside and the outside of the magnetic disk device are ventilated only through the respiratory filter assembly 42.

A filter 46 is adhered to the ventilation inlet 44a from the inside of the casing 44, and a filter 54 is adhered to the ventilation outlet 44b from the outside of the casing 44.

The filters 46 and 54 are made of, for example, polytetrafluoroethylene. In this embodiment, G
ORE-TEX INC. Trade name GTAFL931
4 was used. This filter removes particles larger than 0.1 μm with an efficiency of 99.9999%.

In the casing 44, a fibrous filter or a nonwoven fabric filter 48 is housed adjacent to the ventilation inlet 44a. The fibrous filter 48 is adhered to the inner surface of the casing 44.

The fibrous filter 48 has a crystallinity of about 15
% Amorphous rayon and 3% by weight of iron phthalocyanine, adhered to each other, and bound to a diameter of about 20 mm. The fibers of the fibrous filter 48 are arranged in a direction substantially parallel to the air flow direction from the ventilation inlet 44a to the ventilation outlet 44b.

Inside the casing 44 between the fibrous filter 48 and the filter 54, a layer 50 of activated carbon is accommodated. The activated carbon layer 50 adsorbs and removes corrosive gases in the air passing through the respiratory filter assembly 42.

The activated carbon layer 50 may be mixed with silica gel. The mixing ratio in this case is not particularly limited, but it is preferable to mix silica gel in activated carbon at a ratio of approximately 50%. The silica gel mainly adsorbs water vapor in the air passing through the respiratory filter assembly 42.

In this embodiment, a filter 52 is interposed between the fibrous filter 48 and the activated carbon layer 50. The filter 52 prevents the activated carbon 50 from entering the fibrous filter 48, and may be omitted. The filter 52 is formed from the same material as the filters 46 and 54.

A protective net 56 is provided on the inner surface of the ventilation outlet 44b.
Is glued. The protective net 56 is provided to prevent the filter 54 from being damaged by the activated carbon 50. A plurality of protrusions 61 are formed on the bottom wall of the casing 44, and the protrusions 61 press the flexible printed wiring sheet 36 as shown in FIG.

However, the air flowing from the vent 16a of the cover 16 passes through the filter 46 via the air passage 60 and the vent 44a. The air that has passed through the filter 46 passes through the fibrous filter 48 and is introduced into the activated carbon layer 50.

The fibrous filter 48 has a function of suppressing the diffusion of the inflow air in the activated carbon layer 50 to thereby prevent the life of the activated carbon from being shortened, and increasing the pressure loss of the inflow air to restrict the flow of air. It is.

The air that has passed through the fibrous filter 48 is introduced into the activated carbon layer 50 via the filter 52, where the corrosive gas is adsorbed and removed by the activated carbon. The air from which the corrosive gas has been removed by the activated carbon passes through the filter 54 and is introduced into the magnetic disk drive. The filter 54 is for preventing activated carbon powder from entering the magnetic disk drive.

Since there is almost no corrosive gas inside the magnetic disk device, the flow of air from the inside of the magnetic disk device to the outside hardly shortens the life of activated carbon due to the diffusion of air in the activated carbon layer 50. Therefore, the ventilation outlet 4
It is not necessary to provide a filter having the same function as the fibrous filter 48 on the 4b side.

Referring to FIG. 5, there is shown a sectional view of a respiratory filter assembly according to a second embodiment of the present invention. In this embodiment, the assemblability of the respiratory filter assembly 62 is improved.

As in the first embodiment, the casing 64 has a ventilation port 64a communicating with the ventilation port 16a of the cover 16,
It has a ventilation outlet 64b communicating with the inside of the magnetic disk drive. The casing 64 is adhered to the inner surface of the cover 16 with an elastic double-sided adhesive tape 66.

A filter 70 is adhered to the inner surface of the casing 64 facing the air inlet 64a with a double-sided adhesive tape 68, and a fiber filter 72 similar to the fiber filter 48 of the first embodiment is further provided with a double-sided adhesive tape 68. Is adhered to the inner surface of the casing 64.

Further, a ventilation outlet 6 is provided in the casing 64.
4b, a filter bag 74 containing an activated carbon 76 therein is accommodated therein. The filter bag 74 is manufactured by accommodating activated carbon 76 therein and then closing the ends of the filter by thermocompression bonding. The filter bag 74 used in this embodiment is GORE-TEX INC. Formed by GORE-SORBER.

In this embodiment, since the activated carbon 76 is contained in the filter bag 74, the assemblability of the respiratory filter assembly 62 can be greatly improved. The respiratory filter assembly 62 of this embodiment has the same effects as those of the above-described embodiment. Also in this embodiment, a mixture of activated carbon and silica gel may be accommodated in the filter bag 74.

In any of the above-described embodiments,
The vent outlets 44b of the respiratory filter assemblies 42, 62,
Desirably, the respiratory filter assemblies 42, 62 are positioned such that 64b is located at a pressure slightly lower than the external pressure of the magnetic disk drive during rotation of the magnetic disk.

In the first and second embodiments, the fibrous filters 48 and 72 are used. Instead of these fibrous filters, the fibrous filters 48 and 72 are made of a porous material such as urethane foam or porous ceramic. A filter may be used.

[0053]

As described in detail above, the present invention makes it possible to efficiently adsorb and remove corrosive gas in air with a smaller amount of activated carbon than in the past by combining a fibrous filter with a normal filter. As a result, clean air can be introduced into the magnetic disk device. Further, the present invention can provide a respiratory filter assembly having a small size and a simple structure.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a magnetic disk drive provided with a respiratory filter assembly of the present invention, with a cover removed.

FIG. 2 is a sectional view of the housing of the magnetic disk drive taken along the section of the respiratory filter assembly, including a magnetic disk,
The actuator assembly and the like are omitted.

FIG. 3 is a cross-sectional view of the respiratory filter assembly according to the first embodiment of the present invention.

FIG. 4 is a plan view of the respiratory filter assembly of the first embodiment.

FIG. 5 is a sectional view of a respiratory filter assembly according to a second embodiment of the present invention.

[Explanation of symbols]

 16a vent 42,64 respiratory filter assembly 44,64 casing 44a, 64a vent inlet 44b, 64b vent outlet 48,72 fibrous filter 50,76 activated carbon 74 filter bag

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisashi Kaneko 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Co., Ltd. (72) inventor Masaharu Sugimoto Kanagawa Prefecture, Nakahara-ku, Kawasaki, Kamikodanaka 1015 address Fujitsu within Co., Ltd. (56) reference Patent Sho 62-184685 (JP, a) (58 ) investigated the field (Int.Cl. ^7, (DB name) G11B 33/14

Claims (9)

(57) [Claims] 1. A respiratory filter assembly for a magnetic disk drive, comprising a base (14) and a cover (16) having a vent (16a) fixed to the base, wherein the respiratory filter assembly communicates with the vent (16a). And a casing (44) fixed to the inner surface of the cover (16), having a ventilation inlet (44a) through which the air flows, and a ventilation outlet (44b) provided opposite to the ventilation inlet communicating with the inside of the magnetic disk device. The air inlet (4) housed in the casing adjacent to the air inlet (44a);
A first filter (48) consisting of a plurality of fibers arranged in a direction substantially parallel to the direction of air flow from 4a) to the air outlet (44b);
And the casing (4) so as to close the ventilation outlet (44b).
4) a second filter (54) bonded to the first filter;
A respiratory filter assembly for a magnetic disk drive, comprising an activated carbon layer (50) housed inside the casing between (48) and a second filter (54). 2. The respiratory filter assembly according to claim 1, wherein silica gel is mixed in the activated carbon layer. 3. The respiratory filter assembly according to claim 1, further comprising a third filter (46) adhered to the housing so as to close the ventilation inlet (44a). 4. The second filter (54) and the activated carbon layer (5)
4. The respiratory filter assembly for a magnetic disk drive according to claim 3, further comprising a protection net between the first and second protection nets. 5. The first filter (48) and the activated carbon layer (5)
And a fourth filter (52) between the first filter and the second filter.
A respiratory filter assembly for a magnetic disk drive as described. 6. A respiratory filter assembly for a magnetic disk drive, comprising a base (14) and a cover (16) having a vent (16a) fixed to the base, wherein the respiratory filter assembly communicates with the vent (16a). And a casing fixed to the inner surface of the cover (16), which has a ventilation inlet (64a) through which the air flows and a ventilation outlet (64b) provided facing the ventilation inlet (64a) communicating with the inside of the magnetic disk device. 64); the ventilation inlet (64
a) a first filter (72) comprising a plurality of fibers housed in the casing adjacent to a) and arranged in a direction substantially parallel to an air flow direction from the ventilation inlet (64a) to the ventilation outlet (64b); And a filter bag (74) housed in the casing adjacent to the ventilation outlet (64b) and containing a activated carbon (76) therein. 7. The respiratory filter assembly according to claim 6, wherein silica gel is further accommodated in the filter bag. 8. The respiratory filter assembly of a magnetic disk drive according to claim 6, further comprising a second filter adhered to said casing so as to close said air inlet (64a). 9. A respiratory filter assembly for a magnetic disk drive including a base (14) and a cover (16) having a vent (16a) fixed to the base, wherein the respiratory filter assembly communicates with the vent (16a). And a casing (44) fixed to the inner surface of the cover (16), having a ventilation inlet (44a) through which the air flows, and a ventilation outlet (44b) provided opposite to the ventilation inlet communicating with the inside of the magnetic disk device. A first filter (48) made of a porous material and housed in the casing adjacent to the ventilation inlet (44a); adhered to the casing (44) so as to close the ventilation outlet (44b); The second filter (54)
And a respiratory filter assembly of a magnetic disk drive, comprising: an activated carbon layer (50) housed inside the casing between the first filter (48) and the second filter (54).