JPH0587904B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic disk device used as an external storage device for a computer system or the like.

[Technical background of the invention] In recent years, CSS has been used in magnetic disk devices.
(Contact Start Stop) type is becoming more and more commonly used. This type is
When not in operation, the magnetic head is connected to the magnetic disk head.
Because they are in contact with the landing zone, magnetic disks and magnetic heads are extremely vulnerable to vibrations and shocks. Therefore, it is necessary to keep the carriage fixed except during operation to minimize damage caused by vibrations and shocks.

Conventionally, methods for fixing the carriage include manually pressing the carriage in a certain direction as shown in Figure 5, or fixing it by manually pressing the carriage in a certain direction as shown in Figures 6 and 7.
There is a method of fixing the carriage using a solenoid as shown in the figure.

First, the configuration of FIG. 5 will be explained. In FIG. 5, 1 is a magnetic disk, 2 is the shaft of a spindle motor that rotates the magnetic disk 1, and 3 is a magnetic head that reads and writes data. This magnetic head 3
is attached to the head arm 4, and the head arm 4
is further attached to the arm support block 5.
A coil 6 is attached to the arm support block 5 and driven by a magnet 7 by passing an electric current through it. Reference numeral 8 denotes a pivot, and the carriage comprising the head 3, head arm 4, arm support block 5, etc. moves in an arc with this pivot 8 as the center of rotation. A stopper shaft 9 is attached to the arm support block 5, and stoppers 10 and 11 restrict the range in which the carriage can move. 12 is a carriage base to which the pivot 8, magnet 7, etc. are attached. A shroud 13 covers the magnetic disk, the carriage, etc. and isolates them from the outside air. 14 is a base to which the shaft 2, carriage, etc. are attached. A return spring 15 is hooked onto the arm support block 5 and the spring hanger 16, and constantly pulls the carriage toward the inner circumferential side of the magnetic disk. Reference numeral 17 designates a lock lever, and by manually rotating this lever, vanes 18 press against the coil 6 of the carriage, thereby pressing the carriage against the stopper 10 and fixing it in the head landing zone.

In the case of the structure shown in FIG. 5, the magnetic disk 1 can be moved to a certain extent by requiring scanning by turning the lock lever 17 to the left as shown in the figure during transportation.
The magnetic head 3 can be protected. However, it is difficult to operate the power every time the power is turned on and off during use.
During use, it is easily vulnerable to vibrations and shocks.

6 and 7, FIG. 6 shows a state in which the carriage is locked, and FIG. 7 shows a state in which the carriage is unlocked during normal operation.

In FIGS. 6 and 7, parts different in configuration from FIG. 5 will be explained. 19 is a solenoid, and 20 is a plunger. The plunger 20 has a claw link 21
are movably connected by a pin 22.
23 is a shaft, and the shaft 23 is the center of rotation of the pawl link 21. 24 is a solenoid return spring that pulls the pawl link 21 in the direction opposite to the absorption direction of the solenoid 7. 25 is a lock base to which the solenoid 7, shaft 23, etc. are attached, and is attached to the side of the magnet 7. 2
A fixed claw 6 is attached to the arm support block and engages with the claw link 21 to fix the carriage when the arm is not in operation.

A force is always applied to the inner circumferential side of the magnetic disk 1 in the carriage by the return spring 15, and the coil 6 and magnet 7 apply force enough to overcome the biasing force of the return spring 15 to move any part of the magnetic disk 1. The magnetic head 3 is moved to the position to read and write data. When the power is turned off in the operating state shown in Figure 7, the solenoid 19
is deenergized, and the pawl link 21 connected to the plunger 20 by the solenoid return spring 24 is pushed out to a certain position.

On the other hand, since the carriage is returned to the inner circumferential side of the magnetic disk 1 by the return spring 15,
The fixed claw 26 attached to the carriage and the claw link 21 rub against each other and engage as shown in FIG. 6, and the carriage is fixed.

FIG. 8 shows a structure in which the fixing claws 26 in FIGS. 6 and 7 are replaced with multistage fixing claws 27, the return spring 15 is eliminated, and the carriage is fixed with the power turned off.

[Problems with Background Art] However, in the structure shown in FIGS. 6, 7, and 8, in which the carriage is fixed, it is necessary to keep the solenoid 19 energized at all times when the carriage is movable. There is a problem in that an increase in power consumption and heat generated by the power consumption of the solenoid may cause accidents such as off-tracking due to temperature imbalance of the base.

Furthermore, in the structure shown in FIG. 8, the magnetic head 3 may be fixed in the data area other than the head landing zone, resulting in poor reliability.

[Object of the Invention] In view of the above-mentioned problems, the present invention provides a magnetic disk device equipped with a highly reliable carriage locking mechanism that can lock a carriage in a predetermined position with low power consumption and does not cause off-track. The purpose is to

[Summary of the Invention] Accordingly, the present invention includes: a head arm supporting a magnetic head at one end; a carriage supporting the other end of the head arm so that the magnetic head can move horizontally with respect to a magnetic disk surface; a first locking means fixed to a predetermined location and made of a magnetic material in whole or in part; and a locking part facing the first locking means,
a second locking means to which a permanent magnet is fixed; the second locking means is horizontally moved forward and backward in relation to the magnetic disk surface with respect to the first locking means, and the carriage is horizontally moved; A self-holding solenoid is provided to hold the carriage in an impossible locked state and a horizontally movable unlocked state, and a bidirectional current supply means is provided to the self-holding solenoid to turn the carriage into a locked state or an unlocked state. , to configure a magnetic disk device.

[Embodiment of the Invention] FIG. 1 is a plan view showing an embodiment of a carriage lock mechanism which is a main part of the present invention. In the figure, reference numeral 15 denotes a return spring, which is hooked onto the arm support block 5 and spring hanger 16, and tensions the carriage against the inner circumferential side of the magnetic disk.

Reference numeral 117 denotes a self-holding solenoid, and an arm 119 is rotatably connected to a plunger 118 that moves forward and backward when the solenoid 117 is energized, and a magnet 120 is fixed to this arm 119. Note that the arm 119 is configured to be able to move in the vertical direction in the figure around the rotation center 0. Further, a claw 121 is attached to the magnet 120, and a claw 121 is attached to the magnet 120.
2 constitutes a carriage lock mechanism that engages with the two. The material of the carriage hook 122 may be entirely made of a magnetic material such as iron or nickel, or only the portion of the carriage hook 122 that engages with the claw portion may be made of a magnetic material such as iron or nickel.

FIG. 2 shows an example of the structure of a bidirectional current supply means that energizes the excitation coil in the self-holding solenoid 117 shown in FIG. 1 for a certain period of time. In the figure, a DC power supply V ₁ supplies a voltage V ₅ to the bidirectional current supply means through a diode 31.
This line of voltage V ₅ is connected to the emitters of the transistors 32 and 33 for driving the cartridge solenoid, and the voltage V ₅ is divided by resistors 34 and 35 to become voltage V ₄ and then to the voltage comparator 36.
is input to the positive input terminal of The collector of transistor 32 is connected to the collector of transistor 29, the collector of transistor 33 is connected to the collector of transistor 30, and a self-holding solenoid 117 of FIG.
A built-in coil (excitation coil) 37 is connected. The base of the transistor 32 is connected to the output side of the driver 39 via a resistor 38,
The base of the transistor 33 is connected to the output side of the driver 41 via a resistor 40. Further, the resistor 38 and the output side of the driver 39 are connected to the voltage _V5 line via a resistor 42, and the resistor 40
and the output side of the driver 41 are connected to the voltage V ₅ line via a resistor 43. The base of transistor 29 is connected to the output side of driver 44, and the base of transistor 30 is connected to the output side of driver 45. Also, the transistor 29
The base of is connected to the voltage V ₂ via a resistor 46 and grounded via a resistor 47. The base of transistor 30 is connected to a voltage via resistor 48.
It is connected to V ₂ and grounded via a resistor 49. Further, the emitter of the transistor 29 is grounded via a resistor 50, and the emitter of the transistor 29 is grounded via a resistor 50.
The emitter of is grounded via a resistor 51.

A voltage is applied to the negative input terminal of the comparator 36.
V ₂ is divided by resistors 52 and 53 and inputted as V ₃ . The output side of the voltage comparator 36 is connected to monostable multivibrators 54 and 55. The Q output terminal of the monostable multivibrator 54 is connected to the input sides of the drivers 41 and 44, and the Q output terminal of the other monostable multivibrator 55 is connected to the input sides of the drivers 39 and 45.
connected to the input side of the Furthermore, the monostable multivibrator 54 includes a capacitor 56.
However, a capacitor 57 is connected to the other monostable multivibrator 55, and these capacitors 56 and 57 are connected to resistors 58 and 59, respectively.
A voltage V ₂ is applied through. In addition, the monostable multi-vambrator 54 has a capacitor 5.
6. A high level signal is output from the Q output terminal for a time determined by the time constant of the resistor 58, and similarly, the monostable multivibrator 55 is connected to the capacitor 5.
7 and a high level signal is output from the Q output terminal for a time determined by the time constant of the resistor 59. Further, the transistors 29, 30 and the resistors 46, 47, 48,
49, 50, and 51 constitute a constant current circuit for the coil 37.

The voltage V ₅ line is connected to one terminal of windings 60, 61, 62 of a spindle drive motor (DC brushless motor) of a drive mechanism (not shown),
The other terminals of these windings 60, 61, 62 are connected to the collectors of transistors 63, 64, 65, respectively. Also, these transistors 63,
The emitters 64 and 65 are commonly grounded through a resistor 66. Furthermore, transistors 63, 6
Diodes 67, 68, and 69 are inserted and connected between the collector and emitter of each of 4 and 65, respectively.

The voltage V ₅ is further input to a capacitor 70 and a voltage regulator 71, which outputs a voltage V ₂ .
Note that a capacitor 72 is inserted on the output side of the voltage regulator 71.

Next, the operation of the bidirectional current supply means shown in FIG. 2 will be explained. Voltage V ₁ is a power source for rotating a spindle drive motor of a drive mechanism (not shown), and after passing through diode 31, voltage V ₅ is supplied to motor windings 60, 61, and 62. Changes in this voltage _V5 are as shown in FIG. At a certain point in time, the voltage V ₁ is applied to rotate the magnetic disk 1.
When input, the voltage regulator 71 outputs the voltage _V2 , and the voltage comparator 36, monostable multivibrators 54, 55, and drivers 39, 41, 44, and 45 become operable. At this time, voltages V ₄ and V ₃ shown in FIG. 3 are applied to the positive and negative input terminals of the voltage comparator 36. here,
Since V ₅ > V ₂ , V ₃ < V ₂ and V ₄ < V ₅ , V ₄ >
It becomes _V3 . In this way, when V ₄ >V ₃ , the voltage comparator 36 outputs a high level signal A shown in FIG. The rising edge of the output of the voltage comparator 36 triggers the monostable multivibrator 55, and the monostable multivibrator 55 remains active for a certain period of time determined by the capacitor 57 and resistor 59.
outputs a high-level signal B shown in FIG. 3 from the Q output terminal. This high level output signal B causes the base currents of the transistors 32 and 30 to flow through the drivers 39 and 45, respectively, and turns on these transistors. Therefore, a current flows through the coil 37 in the direction of the arrow in the figure. Note that the current flowing through this coil 37 is the third
As shown in the figure. When a current flows in the direction of the arrow in this coil 37, the plunger 118 of the self-holding solenoid 117 shown in FIG. .
When the high level signal B is no longer output from the Q output terminal of the monostable multivibrator 55 after a predetermined period of time, the transistors 32 and 30 are turned off, and the current in the coil 37 stops flowing.

When the supply of voltage V ₁ is cut off to stop the magnetic disk, voltage V ₅ drops rapidly. However, the windings 60, 6 of the spindle drive motor
1 and 62, a back electromotive force is generated while the motor is rotating due to inertia. At this time, the diode 67,6
8 and 69 are connected, a three-phase half-wave rectified voltage is output to the voltage _V5 line.
If this output voltage is now set to V ₅ , then this
V ₅ is smoothed by a capacitor 70 and supplied to a voltage regulator 71 , transistors 32 and 33 of bidirectional current supply means, and a voltage comparator 36 . This voltage V ₅ is the voltage V ₂ during the period when the rotation does not drop much.
The larger each element is operable.

However, when the inertial rotation of the motor decreases and this back electromotive voltage decreases, the input voltage of the voltage comparator 36 becomes V ₄ <V ₃ . Then, the output of the voltage comparator 36 changes to a low level, and the fall of this output triggers the monostable multivibrator 54, which is determined by the capacitor 56 and the resistor 58. A high level signal C shown in FIG. 3 is output from the Q output terminal for only a period. This high level signal C causes base current to flow through the transistors 33 and 29 via the drivers 41 and 44, turning these transistors on. Then, a current flows in the coil 37 in the self-holding solenoid 117 of FIG. 1 in the direction opposite to the arrow in the figure (indicated by the arrow in FIG. 3), and the plunger 118 of the self-holding solenoid 117 flows as shown in FIG. , and the claw 121 and the carriage hook 122 are engaged with each other.
The current flowing through this coil 37 stops flowing when the output of the monostable multivibrator 54 becomes low level after a predetermined period. The constant current circuit constituted by the transistor 29, transistor 30, etc. described above is provided to keep the current flowing through the coil 37 constant against changes in the voltage applied to the voltage _V5 line.

As described above, in this embodiment, a current in a predetermined direction is caused to flow through the self-holding solenoid 117 for a certain period of time from the bidirectional current supply means, thereby causing the claw 121 and the carriage lock 122 that constitute the carriage lock mechanism to engage and disengage. Since it is possible to create this state, the carriage can be locked in a predetermined position with low power consumption, and off-track can also be prevented since heat generation is no longer a problem.

The locking mechanism of the structure shown in FIG. 8 can also be applied by forming the pawl 121 and the carriage hook 122 into a pawl 121B and a carriage hook 122B having a multi-stage interlocking structure as shown in FIG.

[Effects of the Invention] As explained above, in the present invention, the carriage is controlled into the locked state or the unlocked state by the carriage locking mechanism using a permanent magnet and a self-holding solenoid. All that is required is to drive the self-holding solenoid for a certain period of time in the direction of disengaging the locking portion of the mold solenoid and the locking portion of the carriage. As a result, the carriage can be locked or unlocked in a predetermined position with less power consumption, and since the excitation coil does not need to be driven for a long time, off-track due to heat generation can be prevented, improving reliability. be able to.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the carriage lock mechanism which is the main part of the present invention, FIG. 2 is a circuit diagram showing the configuration of bidirectional current supply means for driving the self-holding solenoid shown in FIG. 3 is a waveform diagram showing the input/output signal waveforms of the main parts of the circuit in FIG. 2, FIG. 4 is a plan view showing another embodiment of the carriage lock mechanism according to the present invention, and FIG. 5 is a diagram showing a conventional main type carriage lock. Figures 6 to 8 showing the mechanism are diagrams showing a conventional carriage lock mechanism using a solenoid. 1...Magnetic disk, 3...Magnetic head, 4...
...Head arm, 5...Arm support block, 1
5...Return spring, 117...Self-holding solenoid, 118...Plunger, 119...
...Arm, 121,121B...Claw, 122,1
22B...Carriage stick.

Claims (1)

[Scope of Claims] 1. A head arm supporting a magnetic head at one end, a carriage supporting the other end of the head arm so that the magnetic head can move horizontally with respect to the magnetic disk surface, and a predetermined portion of the carriage. a first locking means that is fixed and made of a magnetic material in whole or in part, and a locking part that opposes the first locking means;
a second locking means to which a permanent magnet is fixed; the second locking means is horizontally moved forward and backward in relation to the magnetic disk surface with respect to the first locking means, and the carriage is horizontally moved; A self-holding solenoid is provided to hold the carriage in an impossible locked state and a horizontally movable unlocked state, and a bidirectional current supply means is provided to the self-holding solenoid to turn the carriage into a locked state or an unlocked state. A magnetic disk device characterized by: