JPS5811707B2 - magnetic disk device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic disk device that prevents outside air containing dust from entering the magnetic disk shroud even when the magnetic disk stops rotating and the main blower is not operating. .

In order to record and reproduce information on a magnetic disk, it is necessary to float a floating head above the surface of the magnetic disk and maintain a minute flying gap.

If particles such as dust get mixed into the air around the magnetic disk, there is a risk that they will bite into the flying gap and damage the floating head and the magnetic disk.

For this reason, conventionally, this type of loading has been constructed in such a way that clean air is forced into the shroud surrounding the magnetic disk using a blower.

While the magnetic disk is rotating, the air around the magnetic disk moves around at a speed of several tens of meters per second, creating a strongly turbulent flow.

Because such a flow exists within the shroud, outside air is easily drawn in through minute gaps such as the joints and bearings of the shroud, and to prevent this, the pressure of the clean air within the shroud must be increased to at least several tens of U of water column. There is a need.

In addition, in order to prevent an excessive temperature rise due to windage loss due to the rotation of the magnetic disk, several ml/minute of air must be passed through the shroud.

Due to these requirements, a large blower of several hundred watts is required.

This blower is usually stopped at the same time when the operation of the magnetic disk device is stopped.

However, even if a large amount of air is passed through the shroud, the temperature inside the shroud while the magnetic disk is rotating is about 10 to 20 degrees Celsius higher than the outside air, and a cooling process begins when the operation is stopped.

The air inside the shroud contracts as it cools, and the missing air is supplied from outside air.

There are two types of supply channels.

One is the flow path from the stopped blower.

This flow path contains a filter for air purification, and the air flowing into the shroud is purified.

The other is the air outlet from the shroud and the flow path from the shroud joints and bearings.

The air flowing through this flow path is the same as outside air and contains dust.

Conventional equipment also includes a valve that automatically closes the air outlet when the blower stops, but it is difficult to make it completely airtight, and small gaps in the joints of the shroud and bearings are difficult to achieve. The amount of air that flows into the shroud from the flow path that does not pass through the filter reaches several to several tens of cc in one cooling process.

In a normal atmosphere, outside air contains about 100 particles of 0.5 μm or more per cc, and hundreds to dozens of dust particles will enter the shroud during one cooling process.

These particles adhere to the magnetic disk surface over time,
This can cause damage to floating heads and magnetic disks.

This problem can be solved by keeping the blower in operation even when the magnetic disk drive is stopped, but this has the drawback that the power loss of the blower is large, resulting in a large economic disadvantage.

The present invention has been made in view of the above circumstances, and by providing a small, low power consumption sub-blower, it is possible to prevent outside air from entering the shroud at all times.The present invention will be described in detail with reference to the drawings below.

FIG. 1 shows an embodiment of the present invention, in which 1 is a main blower, 2 is a main blower;
is a sub blower, 3 is a switching valve, 4 is a filter, 5 is a shroud, 6 is a magnetic disk, 7 is a positioner, 8 is an exhaust port,
9 is an exhaust port valve.

The main blower 1 and the sub-blower 2 are driven in conjunction with a switching valve 3, and air from either blower is selectively routed to the filter 4.
sent to

The main blower 1 has the same capacity as the blower of a conventional device, and when it is in operation, clean air from which dust has been removed by the filter 4 flows into the shroud 5 and surrounds the magnetic disk 6. The air then passes around a positioner 7 for positioning the floating head above the surface of the magnetic disk 6, and is exhausted from an exhaust port 8.

The exhaust port 8 is provided with an exhaust port valve 9 that opens and closes depending on the exhaust pressure, and when the main blower 1 is in operation, it is opened by the air pressure increased by the main blower 1, and a large amount of air is discharged from there.

The operation of the main blower 1 is linked to the rotational drive of the magnetic disk 6, and while the magnetic disk 6 is rotating, clean air is mainly supplied at a pressure and flow rate sufficient to prevent outside air from entering and preventing an excessive temperature rise inside the shroud 5. It is supplied by blower 1.

When the magnetic disk 6 stops rotating, the switching valve 3 operates,
The flow path from the main blower 1 is closed, and the flow path from the sub blower 2 is opened.

At the same time, the sub blower 2 starts operating.

In this case, since the magnetic disk 6 is not rotating, the air inside the shroud 5 is almost stationary, and the air pressure inside the shroud 5 is reduced by a minute amount (
By simply raising the water column (several mm), it is possible to prevent outside air from entering through the joints of the shroud 5 and minute gaps in the bearing section.

Further, at such a small air pressure, the exhaust port valve 9 is in a closed state.

Based on the operating conditions of the sub-blower 2 as described above, the capacity of the sub-blower 2 is 1710% in pressure compared to that of the main blower 1.
A flow rate of 1/100 to 1/1000 is sufficient.

Specifically, a small blower with power consumption of several watts or less is sufficient.

The switching valve 3 may be electrically operated such as a solenoid drive, but a structure that uses the air pressure generated by the operation of the main blower 1 as shown in Fig. 2 to open and close without using any other power is also available. The purpose of the present invention can be more easily achieved by using the following.

In FIG. 2, 10 is a main blower passage opening/closing valve, and 11 is a sub blower passage opening/closing valve, which are connected in a V shape and rotatably supported by a rotating shaft 12.

Reference numeral 13 denotes an ionizer attached to the rotating shaft 12, and when the air pressure from the main blower 1 does not act on the main blower passage opening/closing valve 10, the main blower 13 hangs down to the position shown by the broken line in FIG. 2 due to its weight. The blower passage opening/closing valve 10 is closed.

This state corresponds to when the magnetic disk 6 stops rotating, and the sub-blower opening/closing unit 11 is in an open state.

Air from the sub-blower 2 flows into the flow path 14 to the filter as indicated by the broken line arrow.

When the sub blower 2 stops and the main blower 1 operates instead,
Due to the air pressure, the six valves 10, 11 and the ionization 13 are
It moves as shown by the thick arrow and reaches the position shown by the solid line.

That is, the sub-blower flow path on-off valve 11 is closed, and the main blower flow path on-off valve 10 is held open.

Note that the cone 13 can also be replaced with a spring.

As explained above, according to the present invention, a small blower is used with a power consumption of several watts or less, and even after the magnetic disk has stopped rotating, it is possible to prevent outside air including dust from entering the shroud. Therefore, damage to floating heads and magnetic disks due to dust can be easily and economically prevented.

When the magnetic disk stops rotating, the sub blower may continue to operate while the magnetic disk drive is stopped, but the operation should be stopped once the temperature inside the shroud has sufficiently approached the temperature of the outside air. Good too.

In addition, switching between the main blower and the sub-blower does not need to be completely consistent with whether or not the magnetic disk is rotating, and the main blower may be left operating if the magnetic disk rotation is stopped for a short period of time. Needless to say.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the magnetic disk device of the present invention.
FIG. 2 is a structural diagram of an example of a switching valve according to the present invention. 1... Main blower, 2... Sub blower, 3... Switching valve, 4... Filter, 5... Shroud, 6...
・Magnetic disk, 7... Positioner, 8... Exhaust port, 9... Exhaust port valve, 10... Main blower flow path opening/closing valve,
11... Sub-blower flow path opening/closing valve, 12... Rotating shaft, 1
3...1 cone, 14...flow path to the filter.

Claims (1)

[Claims] 1. In a magnetic disk device that forcibly pumps clean air into a magnetic disk shroud by a blower, a main blower that mainly operates while the magnetic disk is rotating, and a sub-blower that mainly operates with the main blower stopped while the magnetic disk is not rotating; A magnetic disk device comprising a switching valve that selectively opens and closes flow paths of the main blower and the sub-blower.