JPH0561866U - Magnetic disk unit - Google Patents

Abstract

(57) [Abstract] [Purpose] Equipped with a dynamic load / unload mechanism that realizes complete non-contact start / stop between the floating head and the magnetic disk medium, while avoiding the risk of contact with the head medium during loading operation. Realize operation with small current. A floating head holding mechanism 2 for holding a magnetic head slider support 1 at the time of unloading and a magnetic disk spindle 4 are installed on the same base 5, and a magnetic disk spindle 4 is provided. The floating head holding mechanism 2 has a synchronous controller 10 electrically connected to a positioner actuator 8, and the floating head holding mechanism 2 resonates at a steady rotational speed of the magnetic disk spindle 4 or less. Configure to start operation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic disk device having a load / unload function of a magnetic head.

[0002]

[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 on the disk due to the mechanical effect of the high-speed air flow generated by the high-speed rotation of the disk, and performs recording and reproduction while maintaining a slight gap between the magnetic head and the recording medium. Gimbal spring keeps the spacing of the disk surface protrusion and undulations constant while keeping the spacing constant, so that it can move freely in the pitch, roll, and each direction perpendicular to the disk surface. A gimbal spring is equipped with a load spring that controls the levitation amount of the magnetic head and supports the head for moving the magnetic head on an arbitrary recording track.

On the other hand, in the current magnetic disk device, as a start / stop method, when the rotation of the disk is stopped, the floating head slider and the disk are installed in contact with each other to start the rotation of the disk and increase the number of rotations. The so-called contact start stop (CSS) method, in which the floating head slider is levitated for normal operation and when the disk is stopped, the floating head slider is landed on the disk again due to the decrease in the disk rotation speed, has become mainstream. There is. In this CSS method, the floating head slider and the disk surface are operated through the steps of contact, low-speed sliding, separation, low-speed sliding and contact, which may cause problems of friction and wear. In some cases, the frictional bristles may cause a head crash.

[0004]

[Problems to be Solved by the Invention] Although the CSS system has an advantage that the structure of the mechanism is simple, it has the following problems. That is, the first problem is the problem of contact sliding that is inevitably generated during CSS. When the rotation speed of the disk reaches a certain speed or more, the floating head slider generates sufficient levitation force, so the floating head slider and the disk surface are kept in contact, but immediately after the disk rotation starts. Since the floating force acting on the floating head slider is small, the floating head slider and the disk slide in contact with each other. Such contact sliding occurs even when the disk is stopped, and in this case, the floating head slider transits from the fluid lubrication state to the contact sliding state.

Usually, the floating head slider is made of a material having extremely high hardness such as ceramics. On the other hand, the disk is provided with a protective film formed of carbon or the like for protecting the magnetic recording layer and a lubricant on the surface to reduce frictional resistance and wear during contact sliding with the floating head slider. However, due to the characteristics of magnetic recording, they are formed of a thin film, so their hardness is smaller than that of a floating head slider. Therefore, there is a problem of frictional wear at the time of contact sliding, and fine frictional wear powder generated at this time may hinder the stable motion of the floating head slider in some cases, leading to head crush.

The second problem is that the finishing accuracy of the slider lubrication surface of the floating head slider, which is required to be further reduced in the future, is required to be extremely smooth, and at the same time, the disk surface is also required to have a low flying height of the floating head slider. The requirement for high flatness that does not hinder the volume may cause the floating head slider and the disk to stick to each other when the disk is stopped. Once adsorption occurs, the frictional force increases rapidly, making it difficult to start the disc.

Therefore, in order to avoid the above problems, it is necessary to employ a start / stop system for a disk device in which the floating head slider and the disk surface always operate without contact. There is a force caused by some mechanical system to load the floating head slider from the surface of the magnetic disk medium and to move the floating head slider mounted on the supporting body of the floating head slider to the surface of the magnetic disk medium. It is necessary to unload to let it work.

As is well known, the most general loading / unloading operation is to provide a floating head holding mechanism for holding the floating head slider support in the vicinity of the outermost periphery of the magnetic disk medium, and to use the floating head holding mechanism. Has a structure with an inclined surface inclined in the outer peripheral direction of the magnetic disk medium, so that the floating head slider support which slides on the inclined surface of the floating head holding mechanism is moved up and down as the floating head slider support moves. It is realized by a so-called lamp load method.

However, in the ramp load method, the floating head holding mechanism and the floating head slider support are left in contact with each other when the apparatus is stopped, so that the static frictional force at the contact point between them is large at the start of the loading operation. Therefore, it is necessary to supply a large amount of electric power to the positioner actuator in order to perform the loading operation against the static friction force.

However, supplying a large current at the start of operation has two problems. The first problem is that when a large torque is generated with a large current, the moving speed of the floating head slider support increases after the start of operation, so that an air lubrication film is not formed favorably on the floating head slider during loading. The risk of contact with the head medium increases. Next, the second problem is that, particularly in a small-sized magnetic disk device, the starting torque itself is not promoted due to the limitation of the allowable current, which makes the starting itself difficult.

An object of the present invention is to solve the above problems and to provide a magnetic disk device having a load / unload mechanism that can be started with a low current.

[0012]

[Means for Solving the Problems]

 According to the present invention, a floating head slider, a tongue-shaped leaf spring supporting the floating head slider, and a gimbal spring joined to one end of the gimbal spring to apply a predetermined load to the floating head slider. A floating head slider support consisting of a load spring and a floating head holding mechanism that holds the floating head slider support and slides in contact with the load spring, and moves the floating head slider support by a positioner actuator. A floating head load / unload mechanism for loading or unloading the floating head slider onto the surface of the magnetic disk medium by contacting and sliding the load spring of the floating head slider support to the floating head holding mechanism by movement; , The floating head A magnetic disk device in which a holding mechanism and a magnetic disk pindle are fixed to a common base, which is a low-speed rotation before reaching the rotational speed at which normal magnetic recording / reproduction is performed after the magnetic disk spindle starts rotating when power is turned on. The magnetic head has a motion controller set to start a moving motion of the floating head slider support by the positioner actuator in synchronization with a speed state, and has a fundamental rotation frequency of the magnetic disk spindle at the time of starting the moving motion. It is characterized in that the natural frequencies of the floating head holding mechanism are set to be substantially the same.

[0013]

【Example】

 Next, the magnetic disk device of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view showing an embodiment of a magnetic disk device according to the present invention, and FIG. 2 is a front view showing the relationship of the mechanical elements of this embodiment.

FIG. 1 and FIG. 2 show the configuration of a magnetic disk device having a load / unload mechanism of a floating head called a general ramp load system, and the operating principle thereof is well known and omitted. A pair of floating head slider supports 1 composed of a gimbal spring, a load spring, and a floating head slider are paired and held by a carriage 6, and a positioner actuator 8 serves as a center of rotation of a rotating shaft 7 and a surface of the magnetic disk medium 3. Rotate and move in parallel planes. Then, when the floating head slider support is sufficiently moved to the outer peripheral track of the magnetic disk medium 3, the floating head slider support 1 is brought into contact with the floating head holding mechanism 2 and is lifted by sliding and lifting the floating head slider support 1. The loading operation is performed, and the loading operation is performed in the reverse process. FIG. 2 shows the unloaded state. In this case, the floating head slider support 1 and the floating head holding mechanism 2 are in contact with each other. This unloaded state is a general form in which the apparatus is stopped, and the magnetic disk spindle 4 is stopped rotating.

As shown in FIG. 1, a magnetic disk spindle 4 having a magnetic disk medium 3 mounted thereon is fixed on a base 5, and a floating head holding mechanism for holding a floating head slider support 1 during unloading. 2 is likewise fixed on the base 5. Next, the positioner actuator 8 and the magnetic disk spindle 4 are connected to each other by a synchronous controller 10 by an electrical connecting means 9. This structure is omitted in FIG. 2 for simplicity. The synchronization controller 10 has a function of reading the rotation speed of the magnetic disk spindle 4 via the electrical connection means 9, and when the rotation speed of the magnetic disk spindle 4 reaches a constant value, the synchronization controller 10 disconnects the electrical connection means 9. It has a function of giving a movement command to the positioner actuator 8 via it, thereby causing the floating head slider support 1 to perform a swinging motion, that is, a so-called loading operation is started.

FIG. 3 is a perspective view for explaining the details of the floating head holding mechanism 2 of this embodiment.

The ramp cam 15 is provided with a ramp 12 for starting or ending contact sliding of a floating head slider support 1 (not shown) by a loading / unloading operation, which is included in the floating head slider support 1 Is connected to a floating head slider support holding surface 11 for holding the magnetic disk device while the magnetic disk device is stopped. A pair of thin plate-shaped support beams 14 are coupled to the lamp cam 15, and one ends thereof are further integrated with the base fixing portion 13. The base fixing portion 13 is fixed to the base 5 (not shown).

Here, by appropriately setting the rigidity of the support beam 14 and the mass of the ramp cam 15, the floating head holding mechanism 2 constitutes a vibration system for vibrating the ramp cam 15 in the X direction in the figure. .. The present invention is characterized in that the basic vibration frequency of the floating head holding mechanism 2 is set to be slightly lower than the basic rotation frequency of the magnetic disk spindle 4 (not shown) in the steady state.

FIG. 4 is a frequency response diagram for explaining the relationship between the fundamental vibration frequency in the X direction and the rotation frequency of the magnetic disk spindle 4 shown in FIG. 3 of the floating head holding mechanism of this embodiment set as described above. is there.

Here, the frequency on the horizontal axis shown in FIG. 4 indicates that the basic rotation frequency is synchronized with the rotation speed of the magnetic disk spindle, for example, 60 Hz for a spindle with a steady rotation of 3600 rpm. Further, P1 is the fundamental frequency of the magnetic disk spindle in the steady state in the present embodiment, and P0 is the rotation frequency of the magnetic disk spindle 4 at the point where the loading operation is started by the synchronous controller 10 shown in FIG. is there. Since the magnetic disk spindle 4 is also stopped when the apparatus is stopped, the frequency increases with the start of rotation and passes through P0 to P1. Here, if the loading operation is started at the frequency P0, the resonance characteristic of the floating head holding mechanism 2 at that point is resonating as shown in this figure. This is because the base 5 is forcibly excited by a slight rotational imbalance in the magnetic disk spindle and is transmitted to the floating head holding mechanism 2 as an exciting force to resonate.

At this time, since the floating head slider support holding surface included in the floating head holding mechanism 2 also vibrates in the X direction, a slight slip occurs between the floating head slider support 1 and the floating head slider support 1 which is in contact therewith. become. Therefore, when the loading operation is started by the command from the synchronous controller 10 in this state, only the dynamic frictional force acts between the two at the moment of the operation start, and the static frictional force is exceeded. It does not require a large torque to the positioner actuator 8. This means that the loading operation can be smoothly excited with a relatively small current, and therefore requires a large current at the starting point of start-up, which is a problem with the conventional ramp load method described above. Therefore, it is possible to reduce the risk of contact of the head medium due to this, and it is possible to realize the operation of the positioner actuator 8 within the starting current limit.

As observed in P1 of FIG. 4, the resonance characteristic of the floating head holding mechanism exhibits a follow-up characteristic in a normal rotation state, and therefore the floating head holding mechanism is fatigued due to resonance in a normal device use state. Of course, it is not a reliability issue.

In the present embodiment, for the sake of simplification of description, the device of one magnetic disk medium is described as an example, but it is needless to say that the present invention can be realized as a device having a plurality of disks.

[0025]

[Effect of the device]

 In the magnetic disk device of the present invention, the floating head holding mechanism that constitutes the load / unload mechanism is caused to resonate by the rotational excitation force of the magnetic disk spindle, and at the same time, the loading operation is started in synchronization with the positioner actuator and the magnetic disk spindle. By setting, it is possible to reduce the large current torque required at the start of the loading operation in a magnetic disk device having a conventional load / unload mechanism, and thereby reduce the head and medium caused by the sudden movement of the magnetic head. It has the advantage of avoiding the risk of contact and at the same time being able to start with a small current that meets the current limit.

As a result, in combination with the load / unload mechanism, the probability of occurrence of head crash is greatly reduced, and a highly reliable magnetic disk device can be realized.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a magnetic disk device according to the present invention.

FIG. 2 is a front view illustrating the present embodiment.

FIG. 3 is a perspective view illustrating details of a floating head holding mechanism that constitutes the present embodiment.

FIG. 4 is a frequency response diagram showing vibration characteristics of the floating head holding mechanism of FIG.

[Explanation of symbols]

 1 Floating Head Slider Support 2 Floating Head Holding Mechanism 3 Magnetic Disk Medium 4 Magnetic Disk Spindle 5 Base 6 Carriage 7 Rotation Axis 8 Positioner Actuator 9 Electrical Connection Means 10 Synchronous Controller 11 Floating Head Slider Support Holding Surface 12 Lamp 13 Base Fixed part 14 Support beam 15 Lamp cam

Claims (1)

[Scope of utility model registration request] 1. A floating head slider, a gimbal spring composed of a tongue-shaped leaf spring supporting the floating head slider, and this gimbal spring joined to one end thereof,
The floating head slider has a floating head slider supporting member configured to apply a predetermined load to the floating head slider, and a floating head holding mechanism that holds the floating head slider supporting member and slides in contact with the load spring. Then, the loader of the floating head slider support is brought into contact with and slid on the floating head holding mechanism by the movement of the floating head slider support by the positioner actuator, and the floating head slider is loaded onto the magnetic disk medium surface. Alternatively, a magnetic disk device including a floating head load / unload mechanism for unloading, in which the floating head holding mechanism and a magnetic disk pindle are fixed to a common base, the rotation of the magnetic disk spindle upon power-on. Normal porcelain after start The motion controller has a motion controller set to start the moving motion of the floating head slider support by the positioner actuator in synchronism with the low rotation speed state before reaching the rotation speed for performing air recording / reproducing. A magnetic disk device, wherein the basic rotation frequency of the magnetic disk spindle at the start and the natural frequency of the floating head holding mechanism are set to substantially match.