JPH0397173A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To preclude a contact slide and attraction when a magnetic recording medium is started or stopped by providing a displacement enlarging mechanism capable of contacting part of a suspension spring and a lamination type piezoelectric actuator which drives the displacement enlarging mechanism. CONSTITUTION:The suspension spring 4 which abuts on a pin 24 by moving up and down the pin is put in elevating operation and one end of the suspension spring 4 is fixed to a carriage 5 at this time, so the part of a slider 2 is elevated while the displacement quantity of the pin 24 is further enlarged. The fine displacement of the lamination type piezoelectric actuator 25 is enlarged greatly, and consequently the slider 2 can be unloaded at a sufficient distance from the surface of a magnetic disk 40, so that the possibility of the contacting between the slider 2 and magnetic disk 40 due to disturbance, etc., at the time of the unloading is small. Consequently, the magnetic recording medium and a magnetic disk are held not in contact to evade a problem such as the contact slide and attraction between the slider and magnetic recording medium.

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 featuring a magnetic head load/unload device.

(Prior Art) A magnetic disk device uses a floating head slider having a magnetic head mounted on one end surface thereof. This floating head slider floats above the disk by high-speed airflow generated by the high-speed rotation of the disk, and performs recording and reproduction while maintaining a small gap between the magnetic head and the recording medium. The floating head slider uses a gimbal spring to adjust the pitch, roll,
It is held movably in each parallel direction.

Furthermore, this gimbal spring is connected to one end of a suspension spring for controlling the flying height of the floating head slider and for supporting the head to move the magnetic head onto any recording track.

FIG. 5 is a side view showing an example of how a conventional magnetic head mechanism is used. In the figure, 2 is a slider, 3 is a gimbal spring, 4 is a suspension spring, 40 is a magnetic disk, and 5 is a carriage. The slider 2 is supported by a gimbal spring 3 and joined to one end of a suspension spring 4, while the suspension spring 4 is fixed to a carriage 5 at the other end.

Furthermore, the slider 2 has a structure in which a load is applied by the leaf spring effect at the root of the suspension spring 4 in order to achieve an appropriate amount of levitation. The slider 2 is in contact with the surface of the magnetic disk 40 when it stops rotating, and when the magnetic disk 40 starts rotating and the rotational speed increases, the slider 2 floats above the magnetic disk 40 by a submicron amount due to the hydrodynamic effect. do.

In current magnetic disk drives, as a start/stop method, when the rotation of the magnetic recording medium stops, the floating head slider and the magnetic recording medium surface are placed in contact with each other, and the rotation of the magnetic recording medium is started, and as the rotation speed increases, the floating head slider The so-called contact start/stop (CSS) system levitates the magnetic recording medium and performs normal operations, and when the magnetic recording medium stops, the rotating speed of the magnetic recording medium decreases and the floating head slider lands on the disk again.
method is used. In this method, the floating head slider and the magnetic recording medium surface make contact, low-speed sliding, separation, low-speed sliding,
You will go through each stage of contact.

(Problem to be solved by the invention) The CSS method has the advantage of simplifying the structure of the mechanism, but
It has the following issues. That is, the first problem is the contact sliding problem that inevitably occurs during CSS. When the rotational speed of the disk reaches a certain speed or higher, sufficient levitation force is generated in the floating head slider, so that the floating head slider and the magnetic recording medium are kept out of contact, but immediately after the rotation of the magnetic recording medium starts, The buoyancy force acting on the floating head slider is small, so that the floating head slider and the magnetic recording medium slide while being in contact with each other. Such contact sliding also occurs when the magnetic recording medium is stopped, and in this case, the floating head slider transitions from a fluid lubrication state to a contact sliding state.

Floating head sliders are typically made of extremely hard materials such as ceramics. On the other hand, magnetic recording media have a protective film on the surface to protect the magnetic recording layer and a lubricating film with good sliding properties to reduce the frictional force during CSS, but the hardness of this film is limited to that of the floating head slider. Comparatively small. Therefore, there is a problem of frictional wear during contact sliding, and the fine frictional abrasion powder generated at this time may impede the stable movement of the floating head slider, possibly leading to a head crash.

The second issue is that the finishing precision of the slider lubricating surface of the floating head slider, which will continue to be required to have a low flying height, must be extremely smooth, and at the same time, the magnetic recording medium surface must not interfere with the low flying height of the slider. Because high flatness is required, there is a risk that the floating head slider and the magnetic recording medium may stick together when the magnetic recording medium is stopped. Once adhesion occurs, the frictional force increases rapidly, making it difficult to start up the magnetic recording medium. SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic head loading/unloading device that eliminates the above-mentioned conventional drawbacks and solves problems such as contact sliding and attraction when starting and stopping a magnetic recording medium.

(Means for Solving the Problems) The present invention provides a slider, a gimbal spring that supports the slider, a suspension spring that connects the gimbal spring to one end and applies a load to the slider toward the surface of a magnetic disk medium. Loading/unloading the magnetic head by pushing up the suspension spring in a direction opposite to the load application direction to move the slider away from the magnetic disk medium surface and displacing it in the load application direction to bring the slider closer to the magnetic disk medium surface. In the magnetic disk drive, the magnetic head loading/unloading device includes a displacement amplifying mechanism capable of contacting a part of the surface of the suspension spring facing the magnetic disk medium;
This magnetic disk device is characterized by comprising a laminated piezoelectric actuator that drives this displacement magnifying mechanism.

In particular, the laminated piezoelectric actuator can be compactly stored without taking up space even when multiple magnetic disk media are stacked by placing the expansion and contraction direction parallel to the surface of the magnetic disk medium. effective. In this case, the displacement magnifying mechanism described above has a function of converting the displacement due to expansion and contraction of the piezoelectric actuator into displacement in a direction perpendicular to this. Specifically, a U-shaped housing is connected to the other end of a laminated piezoelectric actuator with a base provided at one end in the expansion/contraction direction so as to surround the laminated piezoelectric actuator, and is located almost on the same plane as the base of the housing. A fulcrum-side hinge is provided on the surface, and an action-side hinge is provided at a position different from the fulcrum-side hinge on the end face opposite to the laminated piezoelectric actuator of the base, and the expansion lever is connected to the partner of the fulcrum-side hinge and the action-side hinge. This can be achieved by providing

Furthermore, by configuring two sets of displacement amplifying mechanisms to be simultaneously driven by one laminated piezoelectric actuator, it can be stored even more compactly.

(Function) According to the magnetic head loading device of the present invention, a displacement magnification mechanism is provided at a position where it can come into contact with a portion of the suspension spring facing the magnetic disk surface, and the displacement magnification mechanism is driven by a laminated piezoelectric actuator. By this, when voltage is applied to or removed from the laminated piezoelectric actuator, the expansion and contraction movement of the laminated piezoelectric actuator can be expanded to a relatively large movement by the displacement magnification mechanism, and the lubricated surface of the slider can be used to stop the magnetic disk. The inside part is set away from the surface of the magnetic disk, and after the magnetic disk starts up and reaches a steady rotation speed, voltage is applied to the laminated piezoelectric actuator, and the part that contacts the suspension spring of the displacement magnification mechanism is moved toward the disk side. By deflecting the slider, the lubricated surface of the slider is brought closer to the rotating magnetic recording medium, and the slider is loaded onto the surface of the magnetic disk. In addition, from this state, the voltage applied to the laminated piezoelectric actuator is removed, and as a result, the displacement of the laminated piezoelectric actuator is removed, and when the magnetic disk stops, a part of the suspension spring is connected to the displacement magnification mechanism. The slider is unloaded by raising it at the end. As described above, in the present invention, by using the magnetic head load/unload device, the floating head and the magnetic disk are always kept in non-contact even when the magnetic disk starts and stops, so there is no frictional wear on the magnetic disk or between the head and the magnetic disk. This can solve problems such as adsorption with discs.

In particular, by using a laminated piezoelectric actuator, it is possible to obtain sufficient force to raise the slider, and the slider can be operated with good controllability. Furthermore, the problem that the laminated piezoelectric actuator cannot achieve sufficient displacement can be solved by providing a displacement magnification mechanism.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a perspective view showing an embodiment of the magnetic head loading/unloading device according to the present invention. Here, as an example of an embodiment, a magnetic head loading/unloading device 10 will be described in which a single stacked piezoelectric actuator loads and unloads two magnetic head supports at the same time. One end of the laminated piezoelectric actuator 25, which can be displaced by the application of a voltage, is fixed in a relatively rigid housing 20, while the other end of the laminated piezoelectric actuator 25 is coupled to a base 26. Here, the housing 20 has an approximately U-shape, and one end thereof is substantially flush with one end of the base 26.

A fulcrum-side hinge 22 is provided on a surface of the housing 20 that is substantially flush with the base 26 . This fulcrum-side hinge needs to be firmly connected to the housing 20, and therefore it is effective to have an integral structure with the housing 20. The fulcrum side hinges 22 are formed symmetrically on both arms of the housing 20, which has a U-shape. In addition, since this example is designed to load and unload two magnetic head supports at the same time, the fulcrum side hinges 22 are provided symmetrically in the thickness direction of the housing 20, so there are a total of 4 fulcrum side hinges 22. exist. Further, the base 26 is provided with an active hinge 21 on the side opposite to the side joined to the laminated piezoelectric actuator 25 . In this case as well, it is effective to be provided symmetrically in the thickness direction of the housing 20 and to be integral with the base 26, similar to the fulcrum side hinge 22. The fulcrum side hinge 22 and the action side hinge 21 are not on the same plane, but are constructed with a certain level difference. Furthermore, two of the fulcrum-side hinges 22 and one of the action-side hinges 21 form a set, and one end of each is coupled to a pair of enlarged levers 23 . In this case as well, it is effective that each hinge and the enlargement lever 23 are of integral construction.

Furthermore, a pair of pins 24 are provided at one end of each of the enlargement levers 23, which come into contact with a magnetic head support (not shown).

FIG. 3 is a side cross-sectional view taken along a neutral line for explaining the operation of the magnetic head load-unload device of this embodiment. As explained in FIG. 2, the working side hinge 2l is joined to the base 26, and the fulcrum side hinge 22 is joined to one end of the housing 20, which is not visible in the figure. When a voltage is applied to the laminated piezoelectric actuator 25 by a voltage supply means (not shown), the laminated piezoelectric actuator 25 expands in the X direction shown in the figure. At this time, assuming that the housing 20 supporting the laminated piezoelectric actuator 25 is firmly fixed to the outside, most of the deformation of the laminated piezoelectric actuator 25 occurs on the base 26 side because the housing 20 has high rigidity. Therefore, in Figure 3,
The base 26 is displaced in the X direction. Here, the fulcrum side hinge 22
is fixed to the housing 20, and the working side hinge 21 is fixed to the base 26, so the working side hinge 21
moves in the X direction relative to the fulcrum side hinge 22. Next, paying attention to the expansion lever 23, the expansion lever 23 is connected to both the action side hinge 21 and the fulcrum side hinge 22, and since each hinge performs the above-mentioned movement, the expansion lever 23 is connected to one end of the expansion lever 23. The fulcrum side hinge 22
and receives a moment from the active hinge 21. It will therefore be readily understood that the other end of the enlarged lever 23 on the side connected to the hinge can move in the two directions shown in the figure. Since the magnifying mechanism is symmetrically constructed in this embodiment, it is clear that the direction of movement is in the negative direction of 2 for the magnifying lever on the upper side of the figure, and in the positive direction for the lower side. The amount of displacement in two directions of the open end of the expansion lever 23 is approximately determined by the ratio of the separation distance in the two directions of the working side hinge 2l and the fulcrum side hinge 22 connected to each expansion lever 23 and the length of the expansion lever 23 in the X direction. It is determined. That is, the two-direction displacement of the open end of the expansion lever 23 increases the expansion ratio as the distance between both hinges is shorter and the length of the expansion lever 23 is longer than the amount of displacement of the laminated piezoelectric actuator 25.゛Since the displacement amount of the generally used laminated piezoelectric actuator 25 is about 10 to 20 microns for a voltage of about IOOV, for example, by increasing this magnification factor to 20 times, the open end of the magnifying lever 23 can be The displacement in two directions is i
It can be 200 to 400 microns per oov. It is clear that this amount of displacement is sufficient to displace a portion of the suspension spring that supports the magnetic head support and to realize loading and unloading of the magnetic head.

FIG. 1 is a plan view illustrating an example of application of the embodiment of the present invention to a magnetic disk device. The magnetic head support 1 is fixed at one end to the carriage 5, and the slider 2 is moved along a head seek locus 43 by a positioner actuator (not shown). In the magnetic disk 40, the inner circumferential side of the track O indicated by 42 is a data area, and in this figure, it is assumed that the slider 2 is on-track on the load/unload track 41 on the outer circumferential side. In this state, the bin 24 for controlling the magnetic head loading/unloading device overlaps the suspension spring 4 constituting the magnetic head support on the side where the slider 2 is present. As explained using FIG. 2, in this state, by raising and lowering the pin 24, the suspension spring 4 in contact with it moves up and down, and at this time, the suspension spring 4 has one end fixed to the carriage 5. Therefore, it goes without saying that the amount of displacement of the bin 24 is further increased in the slider 2 portion, and the bin 24 can be moved up and down. Therefore, the minute displacement of the laminated piezoelectric actuator 25 is greatly expanded, and as a result, the slider 2 can be unloaded sufficiently away from the surface of the magnetic disk 40, and the slider 2 and the magnetic disk 40 can be easily separated from each other due to disturbances during unloading. The possibility of contact is extremely small. Further, it is clear that as long as the pin 24 and the suspension spring 4 are in a non-contact state during the seek operation of the magnetic head support, the seek operation will not be affected in any way.

FIG. 4 is a side view further illustrating the operation of the magnetic head load/unload device of this embodiment. In this figure, parts unnecessary for explanation are omitted. First, when no voltage is applied to a laminated piezoelectric actuator (not shown), that is, when the magnetic disk drive is not operating, the distance between the pins 24 is set to be d in the figure. Depending on this distance, the suspension spring 4 is previously subjected to a slight deformation, so that the slider 2 is unloaded from the magnetic disk 40. After the magnetic disk drive starts operating, a voltage is applied to a stacked piezoelectric actuator (not shown), so that the distance between the bins 24 becomes d' as described above. In this state, the pin 24 and suspension spring 4 are out of contact,
Slider 2 is loaded onto magnetic disk 40. In this embodiment, it is necessary to constantly apply voltage to the laminated piezoelectric actuator during operation of the magnetic disk drive, but there is almost no current flowing through the laminated piezoelectric actuator during the deformation holding operation, and the speed of the load/unload operation is limited. It goes without saying that by adjusting the inrush current during displacement, it is possible to set it to a small amount, and it does not interfere with the system control.

Furthermore, as is well known, a predetermined load is applied to the slider 2 by the suspension spring 4, and a force of several tens of grams is required to overcome the load and perform the unloading operation. It goes without saying that the laminated piezoelectric actuator used in this invention generates an extremely large force, so it is possible to perform the unloading operation sufficiently.

In the above embodiment, an example was shown in which two displacement magnifying mechanisms are driven by one laminated piezoelectric actuator, but the number of displacement magnifying mechanisms may be one. Furthermore, as the laminated piezoelectric actuator, one that contracts when a voltage is applied is also applicable.

Furthermore, in the magnetic head loading/unloading device of the present invention, contact between the bin and the suspension bone is unavoidable;
By using ceramic for the contact part, the wear resistance of the contact part can be improved, and by making the contact part a tapered surface in the slider seek direction, it is possible to unload the slider while seeking. As a result, the slider can be moved to the outside of the magnetic disk by the inertial force applied to the magnetic head support, and the impact resistance of the magnetic disk device when it is not in operation can be further improved.

(Effects of the Invention) As explained above, the magnetic head load/unload device of the present invention sets the slider and the magnetic disk in a non-contact state when the magnetic recording disk is stopped,
- By loading or unloading the slider onto the magnetic disk after the disk rotational speed reaches the rated rotational speed, the magnetic recording medium and the magnetic head can always be kept out of contact, and the slider and magnetic recording medium can be kept in contact with each other. At the same time, by firmly holding the slider through contact between the suspension spring and the pin after unloading, sufficient equipment reliability can be maintained even when the equipment is not in operation. have.

[Brief explanation of drawings]

Fig. 2 is a perspective view showing an embodiment of the magnetic head load/unload device according to the invention, Fig. 3 is a side view of the same, and Fig. 4 is a diagram showing an embodiment of the present invention. FIG. 5 is a side view illustrating the operation of the example, and FIG. 5 is a side view illustrating the usage state of the conventional magnetic disk device. In the figure, 1...Magnetic head support, 2...Slider, 3...
・Gimbal spring, 4...Suspension spring, 5...
・Carriage, 10...Magnetic head loading/unloading device, 20...
・Housing, 2l... Working side hinge, 22... Fulcrum side hinge, 23... Expanding lever, 24... Pin,
25... Laminated piezoelectric actuator, 26... Base, 40... Magnetic disk, 41... Load/unload track, 42... Track 0143... Head seek locus.

Claims (1)

[Claims] a slider, a gimbal spring that supports the slider, a suspension spring that connects the gimbal spring to one end and applies a load to the slider toward the surface of the magnetic disk medium, and a suspension spring that pushes up the suspension spring in a direction opposite to the direction in which the load is applied. and a magnetic head load/unload device that moves the slider away from the magnetic disk medium surface and displaces the slider in the direction of applying the load to bring the slider closer to the magnetic disk medium surface. The unloading device comprises a displacement magnification mechanism capable of contacting a part of the surface of the suspension spring facing the magnetic disk medium, and a laminated piezoelectric actuator that drives the displacement magnification mechanism. Device.