JPH02310856A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To gradually work the withdrawal of a brake pad arm from a holder and the effect of the brake pad arm upon the holder by making the brake pad arm out of a shape memory alloy in its spring for attaching and detaching the holder. CONSTITUTION:When a heater 6 is to be heated up, the spring 5 made of the shape memory alloy positioned in the vicinity of this heater 6 is to be moved in its withdrawing motion shrinking with heat radiated by the heater 6, i.e. the movement of shrinking withdrawal. Force in the direction of an arrow 11 caused by shrinking and withdrawing the spring 5 is increased to be stronger than force of a spring 4 in the direction of an arrow 12, i.e. pressing force of the brake pad arm 3 against the holder 2, thus moving the brake pad arm 3 in the direction of the arrow 11. The brake pad arm 3 is withdrawn from the holder 2 so that the holder is under the released state, releasing itself from this lock while a spindle motor 1 is put under the movable state. By this method, the withdrawal of the brake pad from the holder 2 can gradually be performed in course of time without creating a sudden locking action.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk drive, and more particularly to a magnetic disk drive having a spindle motor locking mechanism.

[Prior Art] Examples of magnetic disk drives having a conventional spindle motor locking mechanism include those shown in FIGS. 3a and 3b.

The spindle motor locking mechanism employed in this conventional magnetic disk drive is based on the spindle motor 31. as shown in FIG. 3a. Coaxial holder 32, holder 32
Brake pad 33 that suppresses rotation and maintains a stationary state
, a solenoid 34 that presses the brake pad 33 into contact with the holder 32 and separates it from the holder 32.

The solenoid 34 is a device that accommodates a magnetic path structure including the movable iron core 35 and a coil (not shown) that magnetizes this magnetic path structure. By exciting the coil with direct current, the movable core 35 receives a force so as to be attracted to the center of the coil, and when current flows through the solenoid 34, the movable core 35 moves in the direction of the arrow 41, and the current to the trenoid 34 When the movable core 35 is cut, the movable core 35 moves in the direction of the arrow 42.

That is, when the power of the magnetic disk device is turned on, a current flows through the solenoid 34, and the movable iron core 35 of the solenoid 34
moves in the direction of arrow 41 as shown in FIG. When the brake pad 33 is detached from the holder 32,
The spindle lock is released and the spindle motor 31 becomes movable.

On the other hand, when the power to the magnetic disk device is cut off, no current flows through the solenoid 34, the movable core 35 moves in the direction of the arrow 42, and the brake pad 33 connected to the movable core 35 also moves in the same direction as described above. . Then, as the brake pad 33 slides in pressure contact with the holder 32, the spindle motor 31 coaxially with the holder 32 stops rotating, and the spindle motor 31 becomes stationary.

[Problems to be Solved] At the same time as the power of the above-mentioned conventional magnetic disk device is cut off, the brake pad 33 moves and comes into pressure contact with the holder 32, thereby performing a brake operation that stops the rotation of the spindle motor 31. However, there was a problem in that the holder 32 and the brake pad 33 slid and generated noise.

Furthermore, the brake pad 33 is easily worn out due to sliding and movement, so there is also a problem in durability.

Furthermore, if the solenoid 34 fails when starting or rotating the spindle motor 31, the power supply to the solenoid 34 will be cut off and the spindle will be automatically locked, resulting in damage to the magnetic disk drive or damage to the magnetic disk. There was also the problem that the data recorded on it could be destroyed.

The present invention has been made in view of the above-mentioned conventional problems, and has an object to gradually release a brake pad from a holder over time without causing a sudden locking action when power is turned off to a magnetic disk drive. It is an object of the present invention to provide a magnetic disk device having a spindle motor locking mechanism that enables the locking mechanism of the spindle motor.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a magnetic disk drive having a locking mechanism for a spindle motor, which maintains a stationary state of the holder by press-contacting the holder coaxially with the spindle motor. brake pad arm and
a spring that presses the brake pad arm against the holder to maintain a stationary state; a spring made of a shape memory alloy that urges the brake pad arm to release the press contact with the holder; and a spring made of the shape memory alloy. This configuration includes a heater that heats and shrinks the.

[Examples] Examples of the present invention will be described below with reference to the drawings.

Figures 1a and 1b are plan views of the first embodiment of the present invention.The spindle lock mechanism of the magnetic disk drive of this embodiment has a holder 2 coaxial with the spindle motor l and a stationary state of the holder 2. A spring 5 made of a shape memory alloy and a spring 5 are used to release the brake butt arm 3 from the holder 2 in the opposite direction to the spring 4 that presses the brake pad arm 3 and the brake butt arm 3 against the holder 2. It is composed of a heater 6 for heating.

Next, the operation of this embodiment will be explained.

FIG. 1a shows the locking mechanism in its resting state, and FIG. 1b shows its movable state.

First, the movable operation will be explained. This movable operation is started when power is turned on to the magnetic disk device.

When the power is turned on, a current is passed through the heater 6, and the heater 6
When the heater 6 begins to heat up, the shape memory alloy spring 5 located near the heater 6 receives the heat generated by the heater 6 and begins to contract and retreat, that is, to begin to retract.

The force in the direction of arrow 11 in the figure generated by the contraction of the spring 5 increases and becomes stronger than the force of the spring 4 in the direction of arrow 12 in the figure, that is, the force that presses the brake pad arm 3 against the holder 2. moves in the direction of arrow 11. Then, the brake pad arm 3 separates from the holder 2, the holder 2 becomes open, the lock is released, and the spindle motor 1 becomes movable.

Next, the stationary operation will be explained. When the power supply to the magnetic disk device is cut off, no current flows through the heater 6 due to the power cut, so heating is stopped and
The spring 5, which had been contracted by the heat of the heater 6, stops its contracting operation.

Further, the spindle motor 1 stops its rotational operation when the power is cut off, and its rotation gradually slows down.

As time passes, the spring 5 begins to be gradually cooled by the surrounding air and returns to its memorized shape.The spring 5 cools and returns to its original shape. That is, as the brake pad arm 3 extends to the state shown in FIG. 1a, the force that tends to move the brake pad arm 3 in the direction of the arrow 11 decreases. Then, the force in the direction of the arrow 11 caused by the contraction of the spring 5 becomes weaker than the force in the direction of the arrow 12 of the spring 4, so that the brake pad arm 3 begins to move in the direction of the arrow 12. On the other hand, the spindle motor l moves the brake pad Arm 3 stops while moving in the direction of arrow 12.

Next, the brake pad arm 3 gradually comes into pressure contact with the holder 2, the holder 2 is fixed, and the spindle motor 1, which is coaxial with the holder 2, becomes stationary.

Next, a second embodiment of the present invention will be described.

The embodiment shown in FIG. 2 has a detection means 21 and a rotation control circuit 22 in addition to the device configuration of the previous embodiment.

The detection means 21 detects the operating state of the heater 6.
The rotation control circuit 22 is a circuit that receives the operating state signal detected by the detection means 21, determines whether it is normal or abnormal, and controls starting and stopping of the spindle motor l.

The operation will be explained below.

When the power of the magnetic disk device is turned on, if the heater 6 does not start heating even though the power is turned on, the one-rotation control circuit 22 receives the operating state signal detected by the detection means 21, and an abnormality has occurred in the heater 6. Therefore, the spindle motor 1 is maintained in a stationary state without being started.

Similarly, when the heater 6 stops heating while the device is in operation, the rotation control circuit 22 similarly receives the operating state signal detected by the detection means 21, determines that an abnormality has occurred in the heater 6, and starts the spindle motor l. Stops rotation and becomes stationary.

The detection means 21 may be one that detects by the current flowing through the heater 6 or one that detects by the heat generated by the heater 6, and any suitable one may be adopted.

That is, in this embodiment, the detection means 21 and the rotation control circuit 22 are used to stop the spindle motor l and maintain the stationary state when an abnormality occurs in the heater 6 during startup or rotation of the spindle motor l. This prevents damage to the device and destruction of data that would occur if the spindle motor l was rotated in the locked state.

[Effects of the Invention] As explained above, in the present invention, the spring for attaching and detaching the brake pad arm from the holder is made of a shape memory alloy.
When the power to the magnetic disk drive is turned off, the spring cools over time, causing the brake pad arm to gradually detach from the holder and become attached to the holder, causing the spindle motor to rotate. This eliminates the possibility of the brake pad becoming unlocked while the brake pad is in use, and also eliminates noise caused by wear of the brake pad arm and sliding contact during locking.

[Brief explanation of drawings]

Figures 1a and 1b are plan views of the first embodiment of the present invention, where Figure 1a shows the locking mechanism in its resting state, Figure 1b shows its movable state, and Figure 2 shows the second embodiment of the present invention. A plan view of the embodiment,
3a and 3b are plan views of a magnetic disk drive having a conventional spindle motor locking mechanism. FIG. 3a shows the locking mechanism in a stationary state, and FIG. 3b shows the same in a movable state. 1 Nispindle motor 2: Holder 3 Nibrake butt arm 4: Spring 5: Spring made of shape memory alloy 6: Heater 21: Detection means 22: Rotation control circuit 31 Nispindle motor 32: Holder 33 Nibrake pad 34: Solenoid 35: Movable Tetsushin Agent Patent Attorney Kihei Watanabe Figure 10 Figure 1b Figure 2

Claims (1)

[Claims] A magnetic disk drive having a locking mechanism for a spindle motor includes a brake pad arm that presses against a holder coaxial with the spindle motor to maintain the holder in a stationary state, and a brake pad arm that presses the brake pad arm against the holder to maintain the stationary state. a spring made of a shape memory alloy that urges the brake pad arm to release the pressure contact with the holder; and a heater that heats and contracts the spring made of the shape memory alloy. disk device.