JPH0469888A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent the deviation and the distortion of a rotation driving part to improve the reliability by controlling the power source of a cooling fan in accordance with the temperature of a head disk assembly detected by a temperature detecting means at the time of receiving and decoding the power- on/off instruction from a higher-order device. CONSTITUTION:An instruction decoder 9 receives and decodes the power-off instruction from a higher-order device 1 to issue a power-off command to a power control circuit 2. This circuit 2 receives this command to immediately turn off the power source of an electronic circuit 3. The temperature of the head disk assembly HDA measured by a temperature measurer 5 and a reference temperature value 6 are compared with each other by a comparator 7, and when the value 6 is higher, the circuit 2 is operated by a thermo signal 8 to turn off the power source of a fan 4 for HDA. When the value 6 is lower, the circuit 2 keeps the power source of the fan 4 turned on by the signal 8, and the HDA is cooled till its temperature is lower than the value 6. Thus, the deviation and the distortion of the rotation driving part of a magnetic head positioning device or a magnetic disk are prevented to improve the reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device having a magnetic disk assembly in which a magnetic disk and a magnetic head are housed in a sealed container.

[Conventional technology]

A typical magnetic disk device includes one or more head disk assemblies (HDA). A head disk assembly i (HDA) is an assembly in which a magnetic disk, a magnetic head, a magnetic head positioning device, a drive motor for the magnetic head positioning device, and a rotational drive section for the magnetic disk are housed in one sealed container. This is the part that records data. When the magnetic disk device is in operation, the magnetic disk rotates at high speed inside the +4 DA, and the drive rotor of the magnetic head positioning device also operates at high speed. The internal temperature of HII) A is lower than that of the surrounding area because of the heat generated by the friction between the magnetic disk and the air caused by the high-speed rotation of the magnetic disk, and the heat generated by the high-speed operation of the drive motor of the magnetic head positioning device. considerably higher than the temperature. For example, if six magnetic disks with a diameter of 9 inches rotate at the same time at 3600 revolutions per minute and perform two consecutive magnetic head positioning operations,
Temperature exceeding 20°C: Because of the rise in temperature, general magnetic disk drives are equipped with a cooling fan to suppress the temperature rise of HI'') A, and by operating this fan. Temperature rise is suppressed by 10°C or more F'1.:m.

In this way, when a magnetic disk drive receives a power-on command from the 1st-position device, the magnetic disk drive's power is turned off.
Turn on the power for the P1T path [-1tei (D Rotates the magnetic disk in A, and at the same time turns on the power to the cooling fan and rotates the cooling fan. Also, turn on the power from the upper fi7 device. When the disconnection command is received, the power supply for the electric circuit 1' is cut off [5, to stop the rotation of the magnetic disk in the HDΔ, and at the same time turn on the power supply for the cooling fan.

Disconnect and also stop the cooling fan.

[Problems to be Solved by the Invention] As mentioned above, in conventional magnetic disk drives, when the power is cut off after continuous operation, the power to the cooling fan is also cut off, causing the cooling fan to stop. Therefore, after the cooling fan stops, the temperature of 1-(1) A begins to rise, and the temperature rises to the same extent as when no cooling fan is provided. -force, +4 DA If the temperature change is large, subtle deviations or distortions will occur in the magnetic head positioning device or the rotational drive section of the magnetic disk, which will deteriorate the accuracy of positioning the magnetic head. If misalignment or distortion occurs in the magnetic head positioning device or the rotational drive unit of the magnetic disk, even if the temperature returns to Hl)A or normal temperature, the accuracy of magnetic and Vd positioning will not change to the state described in 9. Therefore, )(+i) has the disadvantage of being a serious obstacle for A.

[Failure to solve the problem]

The magnetic disk device of the present invention includes a temperature detecting means for detecting the temperature of the head disk assembly, a command decoding means for receiving and decoding a power on/off command from a device, and a cooling means for cooling the head disk assembly. Cooling J'? -1 fan, and a power supply control means for turning on and off the power supply of the cooling fan and the electronic circuit of the magnetic disk device, and a power control means that receives a power on/off command from the positioning device to the magnetic disk device. When the reading is 7, the power supply to the cooling fan is controlled by the power supply control means in accordance with the temperature of the head disk assembly σ) detected by the temperature detection stage -1.

That is, the magnetic disk device of the present invention has the following characteristics: (i'
l: a command decoder that receives a power-off command from the device and decodes it; a power control circuit that receives a power-off command from the command decoder and cuts off the power to the electronic circuit; and a head disk assembly. A cooling fan for cooling the head disk assembly, a temperature measuring device for measuring the temperature of the head disk assembly, and a comparator for comparing the temperature of the head disk assembly measured by the temperature measuring device with a reference temperature value, The power supply control circuit is operated by the signal from the comparator to control the power supply of the cooling fan.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a power supply control circuit for a cooling fan of a head disk assembly according to an embodiment of the present invention.

In FIG. 1, a command decoder receives a power cutoff command from the first device 1, decodes it, and issues a command to the power supply control circuit 2 to cut off the power.

Upon receiving the command, the power supply control circuit 2 immediately outputs the electronic #
=lIIE? t Turn off the power to 3. The power supply for the cooling fan 4 of the HDA is determined by the temperature measured by the temperature measuring device 5.
The temperature of A and the reference temperature value 6 are compared by the comparator 7, and when the reference temperature value 6 is larger than the temperature of HDA, the thermo signal 8 is output.
By making it inactive, the power supply control circuit 2 is activated and disconnected. When the reference temperature value 6 is lower than the temperature of HI) A, the thermo signal 8 becomes active,
The power supply control circuit 2 keeps the cooling fan 4 powered on and cools the HDA until the temperature of the HDA becomes lower than the reference temperature value.

〔Effect of the invention〕

As explained above, the magnetic disk device of the present invention has H
Keep the cooling fan powered on until the DA temperature becomes lower than the reference temperature value, and turn off the cooling fan power only after the HDA temperature becomes lower than the reference temperature value. This has the effect that it is possible to obtain a highly reliable HDA that prevents the occurrence of misalignment or distortion in the magnetic head positioning device or the magnetic disk rotation drive unit.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a control circuit for a power supply for a cooling fan of a head disk assembly according to an embodiment of the present invention. 1... Host device, 2... Power control circuit, 3... Electronic circuit, 4... Cooling fan, 5... Temperature Measuring device, 6... Reference temperature value, 7... Comparator, 8... Thermo signal, 9... Command decoder.

Claims (1)

[Claims] 1. Temperature detection means for detecting the temperature of the head disk assembly; command decoding means for receiving and decoding a power on/off command from a host device; and a cooling device for cooling the head disk assembly. and a power control means for turning on and off the power for the cooling fan and the electronic circuit of the magnetic disk device, and upon receiving and decoding a power on/off command for the magnetic disk device from the host device; . A magnetic disk drive, wherein the power supply control means controls the power supply of the cooling fan in accordance with the temperature of the head disk assembly detected by the temperature detection means. 2. A command decoder that receives and decodes a power-off command from a host device, a power control circuit that receives a power-off command from the command decoder and cuts off power to an electronic circuit, and a head disk assembly. a cooling fan that cools the head disk assembly; a temperature measuring device that measures the temperature of the head disk assembly; and a comparator that compares the temperature of the head disk assembly measured by the temperature measuring device with a reference temperature value; A magnetic disk drive characterized in that a power supply control circuit is operated by a signal from the comparator to control a power supply to a cooling fan.