JP4234634B2 - Magnetic disk unit - Google Patents

Description

This invention relates to a magnetic disk device, in particular, when the magnetic head is moved to the outer circumference of the magnetic disk, about the magnetic disk equipment having a ramp loading mechanism for supporting the state of being spaced apart with a magnetic head from the magnetic disk.

  In recent years, in electronic devices such as personal computers, magnetic disk devices have been widely used as large-capacity memory devices. In general, a magnetic disk apparatus includes a magnetic disk disposed in a base casing that is an apparatus casing, a spindle motor that supports and rotates the magnetic disk, a head actuator that supports the magnetic head, and a head actuator. A voice coil motor to be driven, a substrate unit and the like are provided.

  The head actuator includes a bearing portion attached to the base housing, a plurality of arms extending from the bearing portion, and a suspension extending from each arm, and the magnetic head is attached to the extending end of the suspension. Yes.

  In recent years, small formable personal computers and music playback devices are becoming widespread, and magnetic disk devices mounted on electronic devices of this type are required to have improved reliability against impacts when carried. ing.

  Therefore, in recent years, a mechanism having a ramp load mechanism has been provided as a mechanism for holding the head when the magnetic disk device is not operating. The ramp loading mechanism includes a tab that extends from the tip of the suspension and a ramp that is arranged so that a portion thereof overlaps the outer periphery of the magnetic disk. When the magnetic disk device shifts to a non-operating state, when the head actuator is rotated to the outer periphery of the magnetic disk, the suspension tab rides on the ramp, and the magnetic head is held at a position away from the magnetic disk surface. The

  However, in the magnetic disk apparatus having such a configuration, a part of the ramp overlaps with the peripheral edge of the magnetic disk in the axial direction so that the head actuator can smoothly move between the magnetic disk and the ramp. Therefore, when an external impact, vibration, or the like acts on the magnetic disk device and the magnetic disk vibrates along its axial direction, the magnetic disk may collide with the lamp, and the magnetic disk may be damaged. . When a damage such as a scratch on the magnetic disk occurs, it may be difficult to stably record and reproduce information.

  Therefore, as a prior art for solving this problem, the technique of Patent Document 1 has been proposed. That is, when not operating, the magnetic head is held at a position separated from the surface of the magnetic disk by the ramp load mechanism, and the ramp of the ramp load mechanism is moved forward only when the magnetic head is loaded and unloaded from the magnetic disk. When the magnetic disk device is in operation or not in operation, it is held at a retracted position separated from the magnetic disk. Therefore, even when an external impact or vibration is applied to the magnetic disk device, the collision between the magnetic disk and the lamp can be prevented, and the occurrence of scratches or the like on the magnetic disk can be eliminated.

JP 2002-93090 A (Overview)

  However, in the case of the above-described prior art, a mechanism and a control circuit for moving the lamp back and forth with respect to the end of the magnetic disk are required, which causes a problem in terms of cost. In addition, the provision of these mechanisms and the control circuit in the magnetic disk requires a space occupied by these mechanisms in the magnetic disk device, which makes it difficult to reduce the size of the magnetic disk device.

Accordingly, the present invention has been made to solve the above-described problem. When the magnetic disk device receives an operation shock, it is possible to avoid collision between the magnetic disk and the ramp with an inexpensive structure. Along with providing a mechanism, damage to the magnetic disk and the lamp, it is possible to prevent the occurrence of wear debris, to provide a magnetic disk equipment with improved reliability.

In order to solve the above-described problems, a magnetic disk device according to the present invention includes a base casing, a magnetic disk disposed in the base casing, driving means for supporting and rotating the magnetic disk, and the magnetic disk A magnetic head for recording / reproducing information on / from a disk, an arm supported rotatably, and a suspension extending from the tip of the arm and having the magnetic head attached to the tip. A head actuator that movably supports the magnetic head with respect to the magnetic disk, and a ramp that supports the magnetic head in a state of being separated from the magnetic disk when the magnetic head moves to the outer periphery of the magnetic disk. A ramp mechanism, the ramp load mechanism extending from the suspension, and the magnetic head When moving to the outer periphery of the disc, provided with an engaging portion rides on the lamp, the lamp, at least a portion along the axial direction of the magnetic disk is positioned to overlap with the magnetic disk, the axis of the magnetic disk A movable part movable according to the vibration along the direction, a fixed part for fixing to the base housing, and the movable part is disposed between the movable part and the fixed part. It includes a spring portion for supporting the fixed portion movable in response to vibration along the axial direction, and further, the spring as the main resonance frequency of the movable portion is coincident with the main resonance frequency of the base housing the length and cross-sectional shape of the parts is adjusted, and is characterized in the this.

Further, the magnetic disk equipment according to the present invention comprises a base housing, a magnetic disk disposed on said base housing, a drive means for supporting and rotationally driving the magnetic disk, the information to the magnetic disk A magnetic head that performs recording / reproduction; an arm that is rotatably supported; and a suspension that extends from a tip of the arm and has the magnetic head attached to a tip of the arm. A head actuator that is movably supported with respect to the magnetic disk; and a ramp load mechanism that supports the magnetic head in a state of being separated from the magnetic disk when the magnetic head moves to an outer peripheral portion of the magnetic disk. The ramp load mechanism extends from the suspension, and the magnetic head moves to the outer periphery of the magnetic disk. An engaging portion that rides on the ramp, and the ramp is positioned at least partially overlapping the magnetic disk along the axial direction of the magnetic disk, and is subject to vibration along the axial direction of the magnetic disk. A movable portion that can be moved according to the position, a fixed portion that is fixed to the base housing, and the movable portion that is disposed between the movable portion and the fixed portion, and that vibrates along the axial direction of the magnetic disk. And a spring portion that is supported by the fixed portion so as to be movable in accordance with the fixed portion, and the fixed portion is fixed at a position that becomes a node in the main resonance of the base casing .

According to the present invention, by adopting the configuration as described above, even when an impact is applied in the direction of the rotation axis of the spindle motor during the operation of the magnetic disk device and the base housing vibrates at the main resonance frequency, the lamp is magnetic. Displaces in the same phase as the disk. In other words, since the relative position of the magnetic disk and the ramp does not change, it is possible to avoid the collision between the magnetic disk and the ramp, and it is possible to prevent damage to the magnetic disk and the ramp and generation of wear debris and improve reliability. it is possible to provide a the magnetic disk equipment.

An embodiment in which the present invention is applied to a magnetic disk device, that is, a hard disk drive (hereinafter referred to as HDD) will be described in detail below with reference to the drawings.
As shown in FIG. 1, the HDD has a base case 12 that is a rectangular box-like case with an open top surface, and is screwed to the base case 12 with a plurality of screws, thereby closing the upper end opening of the base case 12. And a top cover (not shown).

  In the base housing 12, for example, two magnetic disks 16 as magnetic recording media, a spindle motor (hereinafter referred to as SPM) 18 as a driving means for supporting and rotating the magnetic disk 16, and the SPM 18 and the magnetic disk 16 are provided. A clamper 17 as a fixing member when mounting the magnetic head, a plurality of magnetic heads 19 for writing and reading information to and from the magnetic disk 16, a head actuator 22 that supports these magnetic heads 19 movably with respect to the magnetic disk 16, A substrate unit 21 having a voice coil motor (hereinafter referred to as VCM) 24 for rotating and positioning the head actuator 22, a ramp load mechanism 25 for holding the magnetic head 19 at a position separated from the magnetic disk 16, and a head IC, etc. It is stored.

A printed circuit board (not shown) that controls the operation of the SPM 18 and the VCM 24 via the board unit 21 is screwed to the outer surface of the bottom wall of the base casing 12.
In the HDD according to the present embodiment, for example, each magnetic disk 16 is formed with a diameter of 65 mm (2.5 inches) and has magnetic recording layers on the upper surface and the lower surface. The magnetic disk 16 is coaxially fitted to a hub (not shown) of the SPM 18 and is held by a clamper 17. The two magnetic disks 16 are rotationally driven by the SPM 18 at a predetermined speed.

  The head actuator 22 includes a bearing assembly 26 fixed on the bottom wall of the base housing 12. The bearing assembly 26 includes a pivot that is erected perpendicularly to the bottom wall of the base housing 12, and a cylindrical hub that is rotatably supported via a bearing that is integral with the pivot. .

  The head actuator 22 includes four arms attached to the hub and extending from the bearing assembly 26, a support frame attached to the bearing assembly and extending in a direction opposite to the arm, and a magnetic head assembly supported by each arm. And a solid. The four arms are positioned in parallel to each other with a predetermined interval and extend from the hub in the same direction.

  Each magnetic head assembly includes an elongated plate-like suspension that can be elastically deformed, and a magnetic head 19 that is fixed to the tip of the suspension via a gimbal portion (not shown). The suspension is constituted by a leaf spring, and its base end is fixed to the tip of the arm by spot welding or adhesion, and extends from the arm.

  Each suspension is integrally provided with a tab extending from its tip. The tab functions as an engaging portion that constitutes a part of the ramp load mechanism 25 described later. The support frame of the head actuator 22 is made of synthetic resin, and a voice coil is integrally embedded in the support frame.

  In a state where the head actuator 22 configured as described above is incorporated in the base housing 12, each magnetic disk 16 is positioned between the two arms. The magnetic head 19 attached to the suspension faces the upper surface and the lower surface of the magnetic disk 16 and sandwiches the magnetic disk 16 from both sides. Each head 19 is applied with a predetermined head load toward the surface of the magnetic disk by the spring force of the suspension.

  The voice coil fixed to the support frame of the head actuator 22 is positioned between a pair of yokes fixed on the base housing 12, and the VCM 24 is mounted together with these yokes and a magnet (not shown) fixed to one of the yokes. It is composed. When the voice coil is energized, the head actuator 22 is rotated, and the magnetic head 19 is moved and positioned on a desired track of the magnetic disk 16. When the HDD is not operating, the head actuator 22 is rotated to a non-operating position on the ramp 25, and excessive rotation beyond the non-operating position is restricted by a stopper provided on the yoke.

  As shown in FIG. 1, when the head actuator 22 is rotated to the non-operation position, the ramp load mechanism 25 that supports each suspension and holds the magnetic head 19 at a position separated from the magnetic disk 16 includes a base housing. 12, a ramp 25 positioned on the outer peripheral side of the magnetic disk 16, and a tab protruding from the tip of each suspension of the head actuator 22.

  A ramp mechanism (hereinafter referred to as a ramp) 25 has a head retraction area in which a tab located at the tip of each suspension slides and stops when the actuator 22 is not operating, and extends along the axial direction of the magnetic disk 16. A movable part 25a that is located at least partially overlapping the magnetic disk 16 and is movable in response to vibration along the axial direction of the magnetic disk, and a fixing part 25b for fixing the ramp mechanism 25 to the base housing 12. The spring portion 25c is disposed between the movable portion 25a and the fixed portion 25b, and is supported by the fixed portion 25b so that the movable portion 25a can move according to vibration along the axial direction of the magnetic disk 16. .

  When the magnetic disk device is used, the magnetic disk 16 is rotated at a high speed by the SPM 18, but it is known from the mounting accuracy when the magnetic disk 16 is mounted on the SPM 18 that vibrations are generated in the axial direction when the magnetic disk 16 is rotated at a high speed. Yes. In particular, the outermost peripheral portion of the magnetic disk 16 vibrates in the axial direction larger than the innermost periphery fixed by the clamper 17. On the other hand, at the outermost periphery of the magnetic disk 16, a part of the ramp 25 is positioned so as to overlap along the axial direction of the magnetic disk 16, and when the vibration of the magnetic disk 16 is large, the magnetic disk 16 contacts the ramp 25. As a result, the data recorded on the magnetic disk 16 is destroyed, or wear debris generated by the sliding of the ramp 25 and the magnetic disk 16 is generated. There is a risk that the wear dust enters the head 19 and destroys data recorded on the magnetic disk 16.

  In the embodiment of the present invention, the portion of the ramp 25 that partially overlaps the magnetic disk 16 in the axial direction is the movable portion 25a, thereby preventing the magnetic disk 16 and the ramp 25 from contacting each other.

Next, the operation of the lamp 25 according to the embodiment of the present invention, that is, the operation of the movable portion 25a, the fixed portion 25b, and the spring portion 25c of the lamp 25 will be described in detail below.
As described above, the outline of the configuration of the HDD of the present embodiment is as shown in FIG. 1 in which the magnetic disk 16 is fixed to the SPM 18 by the clamper 17. The ramp 25 is fixed to the base housing 12 with screws, but in order to perform the loading / unloading operation of the magnetic head 19, the magnetic head 19 has a slight gap with respect to the surface of the magnetic disk 16. A part of the outer peripheral edge of the disk 16 is positioned so as to overlap. The magnetic head 19 is retracted to the ramp 25 when the HDD is not in operation, and after the SPM 18 reaches a predetermined rotational speed, the magnetic head 19 moves onto the magnetic disk 16 by the rotational operation of the head actuator 22 and air Due to the bearing effect, it floats extremely low on the magnetic disk 16 (gap spacing, approximately 5 nm).

  Next, the detailed structure of the lamp 25 of this embodiment will be described with reference to FIG. 2A is a front view of the lamp 25 according to the present embodiment, and FIG. 2B is a side view of the lamp 25 of the present embodiment.

  The ramp 25 has a shape in which the movable portion 25a and the fixed portion 25b are coupled by a spring portion (hereinafter referred to as a parallel spring) 25c. In the present embodiment, the spring portion 25 c is formed in a plurality of parallel thin plates and has elasticity in the axial direction of the magnetic disk 16. Therefore, the movable direction of the movable portion 25a is limited to the rotation axis direction of the magnetic disk 16, that is, the translational one direction.

  Regarding the length and the cross-sectional shape of the parallel spring 25c, the spring constant of the parallel spring 25c is such that when the fixed portion 25b is completely fixed to the base housing 12, the main resonance frequency of the movable portion 25a is the magnetic in which the same lamp 25 is incorporated. It is designed to match the main resonance frequency of the base casing of the disk device. The design parameters are the length, width, and thickness of the leaf spring of the spring portion 25c.

  The parallel spring 25c is made of the same resin material as that of the lamp 25, or the leaf spring portion is made of metal and is integrally formed with the movable portion 25a and the fixed portion 25b. Alternatively, only the movable portion 25a can be made of a resin material, and the parallel spring 25c and the fixed portion 25b can be made of metal. At this time, the resin material may be injection-molded and integrally molded with the metal material.

Next, the configuration and operation of the HDD according to the embodiment of the present invention will be described with reference to FIG.
A magnetic disk 16 is fixed to the SPM 18 incorporated in the base housing 12 by a clamper 17. A fixed portion 25b of the lamp 25 is fixed to the base housing 12 with screws 27, and the movable portion 25a overlaps the outer peripheral edge of the magnetic disk 16 with a slight gap with respect to the surface of the magnetic disk 16. Located.

  When an impact in the rotational axis direction of the SPM 18 (hereinafter referred to as the Z direction) is applied to the magnetic disk device, the base casing 12 elastically vibrates, but the main resonance mode is dominant, so the magnetic disk 16 Also vibrate in the Z direction. At this time, the fixing portion 25b of the lamp 25 is fixed at a position that becomes a node in the main resonance of the base housing 12, and the movable portion 25a also vibrates in the Z direction in phase with the vibration of the base housing 12. The contact between the magnetic disk 16 and the lamp 25 can be avoided.

Next, the dimensional design of the parallel spring 25c, which is the spring portion of the lamp 25 in this embodiment, will be described in detail with reference to FIG.
In FIG. 4A, m [kg] represents the mass of the movable portion 25a of the lamp 25. As shown in FIG. 4B, when the Young's modulus of the leaf spring is E [Pa], the length is L [m], the width is b [m], and the thickness is t [m], the basic vibration of the parallel spring is obtained. The number f1 is as follows.

For example, when polyacetal (E = 3.2 × (10 9) [Pa]) is used as the lamp material,
L = 1.5 × (10 to the third power) [m],
b = 1.0 × (minus the square of 10) [m],
t = 1.0 × (10 to the fourth power) [m],
m = 1.5 × (10 to the fourth power) [kg]
As a result, f1 is approximately 890 [Hz].
Alternatively, when the parallel spring 25c is made of stainless steel (SUS304, E = 1.93 × (10 11 [Pa]),
L = 2.5 × (10 to the power of 3) [m],
b = 6.0 × (minus the third power of 10) [m],
t = 5.0 × (10 to the fifth power) [m],
m = 1.5 × (10 to the fourth power) [kg]
When f1 is calculated as follows, f1 is approximately 880 [Hz].
The main resonance frequency of the base casing 12 often exists in the vicinity of 800 [Hz], and if the dimensional design of the parallel spring 25c is strictly performed, it is possible to make f1 and the main resonance frequency of the base casing 12 coincide. Become.

  As described above, according to the embodiment of this structure, even when the shock is applied in the rotation axis direction of the SPM 18 during the operation of the magnetic disk device and the base housing 12 vibrates at the main resonance frequency, the ramp 25 is in phase with the magnetic disk 16. Displace at. That is, since the relative position between the magnetic disk 16 and the ramp 25 does not change, the magnetic disk 16 and the ramp 25 can be prevented from colliding with each other. Therefore, damage to the magnetic disk 16 and the lamp 25 and generation of wear debris can be prevented, and it is possible to provide a magnetic disk device with improved reliability and a ramp used in the magnetic disk device.

1 is a perspective view of a magnetic disk device (HDD) according to an embodiment of the present invention. The front view (a) and side view (b) of the lamp | ramp which concern on embodiment of this invention Configuration and operation explanatory diagram of HDD according to an embodiment of the present invention Explanatory drawing of the dimension design of the spring part (parallel spring) which concerns on embodiment of this invention

Explanation of symbols

12. Base housing 16 ... Magnetic disk 17 ... Clamper 18 ... Spindle motor (SPM)
22 …… Head actuator 24 …… Voice coil motor (VCM)
25 …… Ramp loading mechanism (lamp)
25a …… Moving part 25b …… Fixing part 25c …… Spring part (parallel spring)
26 …… Bearing assembly

Claims (2)

A base housing;
A magnetic disk disposed in the base housing;
Driving means for supporting and rotating the magnetic disk;
A magnetic head for recording and reproducing information on the magnetic disk;
An arm that is rotatably supported; and a suspension that extends from the tip of the arm and has the magnetic head attached to the tip of the arm, the magnetic head being movable with respect to the magnetic disk. A supported head actuator;
A ramp loading mechanism for supporting the magnetic head in a state of being separated from the magnetic disk when the magnetic head is moved to the outer periphery of the magnetic disk;
With
The ramp load mechanism includes an engaging portion that extends from the suspension and rides on the ramp when the magnetic head moves to the outer peripheral portion of the magnetic disk.
The ramp is positioned at least partially overlapping the magnetic disk along the axial direction of the magnetic disk, and is movable according to vibration along the axial direction of the magnetic disk, and the base housing And a spring that is disposed between the movable portion and the fixed portion, and is supported between the movable portion and the fixed portion so as to be movable in response to vibration along an axial direction of the magnetic disk. And comprising
Furthermore, the length and cross-sectional shape of the spring part are adjusted so that the main resonance frequency of the movable part matches the main resonance frequency of the base casing.
Magnetic disk device comprising a call. A base housing;
A magnetic disk disposed in the base housing;
Driving means for supporting and rotating the magnetic disk;
A magnetic head for recording and reproducing information on the magnetic disk;
An arm that is rotatably supported; and a suspension that extends from the tip of the arm and has the magnetic head attached to the tip of the arm, the magnetic head being movable with respect to the magnetic disk. A supported head actuator;
A ramp loading mechanism for supporting the magnetic head in a state of being separated from the magnetic disk when the magnetic head is moved to the outer periphery of the magnetic disk;
With
The ramp load mechanism includes an engaging portion that extends from the suspension and rides on the ramp when the magnetic head moves to the outer peripheral portion of the magnetic disk.
The ramp is positioned at least partially overlapping the magnetic disk along the axial direction of the magnetic disk, and is movable according to vibration along the axial direction of the magnetic disk, and the base housing And a spring that is disposed between the movable portion and the fixed portion, and is supported between the movable portion and the fixed portion so as to be movable in response to vibration along an axial direction of the magnetic disk. And comprising
The fixed portion is fixed at a position that becomes a node in the main resonance of the base casing.
Magnetic disk device shall be the feature and this.

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