JPH0679437B2 - Outside air vent structure of magnetic disk unit - Google Patents

Description

The present invention relates to an outside air vent structure of a magnetic disk device,
In particular, the present invention relates to a filter assembly having a flow path with a large resistance to prevent inflow of moisture from the outside, and an outside air vent structure of a magnetic disk device having the filter assembly.

[Conventional technology]

A conventional device has a structure in which a desiccant, a filter and a diaphragm are integrally fixed to a base as described in JP-A-62-153699.

[Problems to be Solved by the Invention]

According to the above conventional technique, since the external filter portion has only one vent hole, after the device is assembled, the air inside the device is replaced with the dry air, and the air is smoothly sucked for the measurement of the degree of dust. And I couldn't get out. Also, if the dry air is forcibly replaced, the internal pressure of the device will fluctuate excessively, grease and dust may flow in through the spindle motor bearing, and the magnetic fluid seal may break, resulting in a disk-shaped disc. There was a problem of causing corrosion and head crash.

Further, in the conventional technique, since the desiccant is attached from the outside of the device, there is a problem that the mounting space is provided outside the device and it is difficult to reduce the board mounting space. Especially in the 5 inch / 3.5 inch small magnetic disk device, the external dimensions of the device are standardized, and it is obvious that the reduction of the mounting space is disadvantageous.

Further, in the prior art, since there is no restriction in the air inflow path, there is a problem that the diffusive inflow of moisture from the outside air and the inflow due to the pressure difference between the inside and outside of the device are freely performed, and the life of the desiccant becomes short. . To extend the life, it is necessary to increase the amount of desiccant, but this causes a problem that the outer shape of the device becomes larger.

It is a first object of the present invention to provide an outside air vent structure for a magnetic disk device that does not increase the external dimensions of the device.

It is a second object of the present invention to provide an outside air vent structure for a magnetic disk device that facilitates replacement of dry air in the device during device assembly.

A third object of the present invention is to provide an outside air vent structure for a magnetic disk device, which can prevent dust from flowing in at the time of measuring the degree of airtightness or dust in the device and which is easy to work with.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, a desiccant assembly having a filter attached is arranged inside the apparatus, and two vent holes for the outside air are provided in a portion separate from the desiccant. One of the vent holes is sealed with a detachable member, and the other vent hole is detachably attached with a filter and a throttle member for restricting an inflow amount of outside air.

Further, the material of the member to be sealed in the vent hole by the member detachable is made of chloroprene rubber, neoprene rubber, nitrile rubber, ethylene propylene rubber, silicon rubber, fluorine rubber, butyl rubber or natural rubber.

Further, a through hole is provided at the center of the diaphragm member, a groove is formed in a spiral shape from the end portion of the through hole on one end surface, and another member is covered from above the groove. The member above the groove is perforated and connected to the terminal end of the spiral groove to form a conduit with increased conduit resistance.

[Operation] When the air inside the apparatus is replaced with dry air during the assembly work in the dustproof chamber, one of the two outside air vents is provided with the filter from the inside and the other is left open. next,
Dry air is sucked into the inside of the device through a ventilation port where the filter is fixed from inside the device, and exhausted through the other ventilation port. After completing the replacement work, cover the exhaust vent with a removable member. Next, in this state, a thin tube such as a needle is inserted into the detachable member, the suction port of the dust measuring instrument is connected from this tube, and the dust concentration is measured. At this time, since the other vent has a filter, it is possible to prevent dust from entering from the outside, and it is possible to correctly measure dust inside the device.
Further, in this state, the dust concentration can be measured in the atmosphere because the filter is connected to the outside of the apparatus, and the workability is improved. After the measurement of dust concentration is completed, the pipe parts forming the throttle are fixed from the outside of the base to limit the inflow of moisture from the outside.

Next, in this state, by closing a minute hole of the pipe line component forming the throttle with the outside of the device, a pipe for measuring the sealing degree is inserted through a detachable member to measure the sealing degree of the device. be able to.

Therefore, in the device having the vent hole forming the throttle for limiting the inflow of moisture from the outside air inside the device, the efficiency of the assembling work can be improved by adopting the above shape.

In addition, by making the material of the parts to be sealed in the ventilation hole with a removable member made of rubber, firstly, the sealing at the time of inserting and pulling out the measuring tube when measuring the degree of sealing and measuring the dust concentration. Since it has good properties, the work associated with the measuring tube is not particularly necessary, and the hole is closed no matter how many times the measurement is performed. In addition, the variable formation of the rubber facilitates the work of pulling out and inserting the rubber itself, thereby improving the work efficiency.

Furthermore, by making the shape of the throttle member a line-shaped groove and covering it from above with another member, a thin and long conduit can be easily created.

〔Example〕

 An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a sectional view of an apparatus showing an embodiment of the present invention.
The base 1 is attached with the spider motor 9, the pivot base 14 and the voice coil motor 22. Discs 10 and disc spacers 11 are alternately stacked on the spindle motor 22 and fixedly coupled by the uppermost disc clamp 12. In addition, the head arm 1
5, Head spacers 17 are mounted alternately and fixed by head clamps 18 at the upper part, pivot shaft (not shown)
Rotate and swing around. A head 16 for reading and writing information on the disk is fixed to the tip of the head arm 15. Further, a coil 21 for generating a driving force for moving and positioning the head 16 to a predetermined position on the disc is a head arm via a spacer coil 20.
The other voice coil motor is fixed on the base 1.

Furthermore, fix the cover 2 from the upper part of the base 1 and attach these assemblies to the HDA (head disk assembly).
The HDA has a closed structure, and the spindle motor 9 and the pivot base 14 are fixed from above.

Next, the closed container 25 containing the desiccant 3 is fixed in the HDA. The closed container 25 has a filter 4 for preventing the dust generated by the wear of the desiccants from flowing out into the HDA,
The humidity inside the HDA is controlled through the micro holes 28.

On the other hand, in the lower part of the base 1, ventilation holes 26, 27 are provided for replacing the air inside the HDA with dry air during assembly work, and for density measurement and dust measurement. The vent hole 26 is provided in the lower portion of the disc 10 having a mounting space, but it need not necessarily be in the lower portion of the disc 10. A rubber member 26 is inserted into the vent hole 26 to close the vent hole 26 during normal operation of the device. The filter 5 is adhesively fixed from the inside of the base 1 to the other vent hole 27, and forms a throttle for limiting the inflow of outside air containing moisture from the outside of the base 1 into the HDA. The member 6 is detachably fixed.

According to the present embodiment, during the assembling work, the rubber member 8 of the ventilation hole 26 for exchanging the HDA internal air with the dry air and the ventilation hole 27 are not attached to the member 6 in which the throttle 6 is formed. By inflowing the dry air from 27 and exhausting it from the ventilation hole 26, the dust in the dry air can be removed by the filter 5. Next, at the time of measuring the degree of dust, the rubber member 8 is attached, the measuring needle is inserted into the rubber member 8 of the ventilation hole 26, and connected to the dust measuring instrument. Since the dust measuring device performs the suction process, the inside of the device has a negative pressure with respect to the external pressure and the outside air flows in through the filter 5, but since the outside air flows through the filter 5, there is no problem in mixing the outside air with dust. Therefore, this work can be performed in the atmosphere and does not need to be performed in the dustproof chamber, so that workability is improved.

Next, in the case of measuring the device airtightness, after the member 6 having a diaphragm is attached, the vent hole of the member 6 is closed or the member 6 is closed.
Before mounting, the measurement can be performed by inserting a sealing degree measuring tube into the rubber member 8 with the ventilation hole 27 closed. Since this member and the dust measuring member can attach and detach the member 6 forming the diaphragm from the outside of the apparatus, the work procedure can be reversed, and the work can be performed in the atmosphere, thus improving work efficiency.

Since a general dust measuring device sucks the air in the HDA with a large negative pressure, when the measurement is performed with the member 6 forming the throttle of the ventilation hole 27 attached, the conduit of the member 6 forming the throttle is measured. Since the resistance is large, the inside of the HDA becomes a large negative pressure against the outside air. The spindle motor 9 uses a labyrinth or a magnetic fluid seal to prevent the inflow of dust between the outside air and the HDA. The negative pressure inside the HDA is 1000 mmH ₂ O or more, and the pressure resistance of the magnetic fluid is 100. since ~200mmH a ₂ O, causing HDA in pollution due to the destruction and the outside air inlet. Therefore, it is necessary to remove the member 6 that forms the throttle of the vent hole 27. In this case, since the filter 5 is fixed to the base 1 in the vent hole 27 separately from the member 6 forming the throttle, when the member 6 forming the throttle is removed, the outside air flowing through the vent hole 27 is Since it passes through the filter 5, the outside air that is always clean flows into the HDA. For this reason, the filter 5 and the member 6 forming the diaphragm are separated. Since this work removes the member 6 forming the throttle, it mixes with outside air moisture, and therefore it should be originally performed in a dry atmosphere or before a dry air replacement work. Therefore, by adopting the above structure, the vent holes 26, 27 can be used in any work.
With this structure, it is possible to deal with all changes in the work sequence, and there is an effect of improving workability.

Further, the airtightness measurement and the dust measurement have an effect that the work can be performed even in the air if the humidity control in the air is performed, and the range of change of the work procedure is increased. Further, when the member 6 forming the diaphragm and the rubber member 8 are removed at the time of repairing the apparatus, the parts can be reused by washing.

FIG. 2 is an enlarged view of the vent hole 27. Inside the base 1,
Counterbore holes are respectively formed from the outside, and a filter 5 is adhered and fixed to the counterbore on the HDA inner side to remove dust of air flowing into the HDA through the ventilation holes 27. Also,
In the countersunk hole on the outside of the base 1, a member 6 forming a throttle having a large conduit resistance for limiting the amount of atmospheric air flowing into the HDA is detachably attached.

3A and 3B are enlarged views of the member 6 forming the diaphragm. In order to have a large conduit resistance, the member 6 forming the throttle is formed with an elongated channel having a small cross-sectional shape. In this example, a through hole 29 is formed in one of the members 6. Then, the spiral groove 30 is formed on the end surface of the member 6 from the end of the through hole 29, and the other member 6 is formed.
Is fixed from above so as to cover the spiral groove 30 and a ventilation hole is provided at the position of the end of the spiral groove, so that a thin conduit can be formed easily and long.

FIG. 4 is an enlarged view of the vent hole 26. The base 1 has a shape such that the rubber member 8 can be inserted from the outside of the base.
Since the rubber member 8 is made of a material having a hardness of about 40 °, for example, it can be removed. With a hardness of this degree, even if the injection needle for measurement is inserted and removed, there is no problem because there is no decrease in the degree of tightness and the inflow of outside air dust.

FIG. 5 is a perspective view of the apparatus. The base 1 is provided with ventilation holes 26 and 27. Further, the spindle motor 9, the pivot base 23, and the voice coil motor 22 are fixed with screws. Discs 10 and disc spacers 11 are alternately mounted on the spindle motor 9, fixed by a disc clamp 12, and rotated about the shaft of the spindle motor 9. In addition, the upper end of the shaft of the spindle motor 9 is covered by the cover 2.
It is fixed with screws 13.

A carriage assembly 14 is mounted on the pivot base 23, and is supported so as to be swingable around the shaft of the pivot base 23. In the carriage assembly, the head arm 15 having the head 16 fixed to one end and the head spacer (not shown) are alternately stacked, the uppermost part is fixed by the head clamp 18, and the coil 21 is fixed to one of the head spacers. Bobbin 20 is connected. Furthermore, the carriage assembly 14 has an FP that processes signals when the head 16 reads and writes.
C24 is connected. Further, the closed container 3 in which the filter 4 is attached to the base 1 and the desiccant is put therein is fixed by screws.

〔The invention's effect〕

According to the present invention, two air vents for the outside air are provided, one of which is detachably covered with a rubber member, and the other of which has a filter fixed from the inside of the HDA and detachable from the outside of the HDA. By fixing with a member that forms a throttle with a flow path with high road resistance, dry air replacement work inside HDA, sealing, and dust measurement work can be performed smoothly during assembly work, and there is an effect of improving work efficiency .

[Brief description of drawings]

FIG. 1 is a transverse cross-sectional view of an apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a ventilation hole in which a member that forms a throttle that narrows a pipeline and a filter are mounted, FIG. (B) is an enlarged view of a member forming a narrowed pipe, (a) is a perspective view, (b) is a sectional view thereof, and FIG. 4 is an enlarged sectional view of a vent hole into which a rubber member is inserted, FIG. 5 is a perspective view showing internal components of the apparatus. 1 ... Base, 2 ... Cover, 3 ... Desiccant, 4 ... Filter, 5 ... Filter, 6 ... Member for forming diaphragm, 8 ... Rubber member, 10 ... Disc, 13,19 …… Screw, 22 …… Voice coil motor, 25 …… Airtight container, 26 …… Vent hole 1, 27 …… Vent hole, 28 …… Vent hole, 29 …… Through hole, 30 …… Helix shaped groove, 31 ...... Ventilation holes.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuichi Koizumi, 2880, Kozu, Odawara, Kanagawa, Ltd., Odawara Plant, Hitachi Ltd. (72) Yuju Aihara, 2880, Kozu, Odawara, Kanagawa, Ltd., Hitachi, Ltd., Odawara In the factory (56) References JP 62-71083 (JP, A)

Claims (3)

[Claims] 1. A disk for storing information, a spindle motor for holding and rotating the disk, a head for writing / reading information to / from the disk, and a head for mounting the head and mounting the head. In a magnetic disk device comprising an actuator for moving and positioning on a disc, a base for supporting and fixing these parts, and a cover for sealing with the outside air, two outside air ventilation holes are provided, and one ventilation hole is used as a device. It is characterized in that it is sealed by a member removable from the outside, a filter is fixed to the other ventilation hole from the inside of the device, and a throttle member for limiting the inflow of outside air is detachably attached from the outside of the device. The outside air vent structure of the magnetic disk device. 2. The removable member is made of chloroprene rubber, neoprene rubber, nitrile rubber, ethylene propylene rubber, silicone rubber, fluororubber, butyl rubber or natural rubber. An outside air vent structure of the magnetic disk device according to the item. 3. The outside air vent structure for a magnetic disk drive according to claim 1, wherein said throttle member is formed of a thin spiral tube.