JP2005327374A - Head holding member and disk drive equipped with same, and head holding method of disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head holding member which prevents a tab part of a head support arm or a lamp part from being damaged owing to a shock by suppressing small a shock due to a collision that the tab part has against the lamp part when an actuator is moved to a standby position when the power supply is stopped. <P>SOLUTION: In the disk drive equipped with the actuator and head holding member, the actuator has the tab part 8a at one end, the head support arm where a head slider is arranged is configured to rotate together with a voice coil on a shaft having a support axis perpendicular to the axis of a rotary shaft at right angles to a surface of a recording medium 4; and a 1st step-side surface 14d and a 3rd slope 14f having specified angles respectively are formed on both sides of a head holding plate 14e of a lamp block holding the tab part 8a at a standby position when the recording medium 4 stops rotating and then the actuator, i.e. the tab part 8a is held at the standby position while a shock is suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a head holding member of a disk device having a floating signal conversion element (magnetic head), a disk device including the same, and a head holding method in the disk device, and more particularly, to a head holding mechanism of the disk device. The present invention relates to a head holding member at a retracted position of an actuator, a disk device provided with the same, and a head holding method in the disk device when the actuator to be operated is unloaded.

  When the operation of the disk device is stopped, the actuator equipped with the signal conversion element is unloaded from the area where the data is recorded and moved to a predetermined area (parking zone) on the recording medium, Alternatively, the signal conversion element is moved and held at a predetermined position near the outer periphery of the recording medium that is not in contact with the surface of the recording medium. That is, the actuator is held at a predetermined retracted position when the disk device is stopped. Furthermore, when an external impact is received when the disk device is stopped, the actuator moves from the retracted position to the data recording area on the recording medium, and the data on the recording medium is caused by the collision between the signal conversion element and the recording medium surface. Damage to the surface of the data area on the recording medium due to damage to the surface of the area or sliding with the signal conversion element by starting operation from the state where the data recording area remains in contact with the data recording area when moved to the data recording area Or to hold the actuator in a predetermined retracted position so that a fatal failure such as damage to the component or the actuator due to the collision of the actuator with another component of the disk device does not occur. An actuator holding member or holding method is employed.

  Hereinafter, an example of a disk device having a holding member for a conventional actuator will be described. First, for a disk drive device having an actuator holding member, a protrusion provided integrally with the other end of the actuator arm having a conversion head (corresponding to the signal conversion element described above) at one end and a coil attached to the other end An iron piece is attached to the actuator and is rotatably attached around a rotation axis to constitute an actuator which is a voice coil motor (hereinafter referred to as a VCM), and is also opposed to the iron piece disposed on the actuator arm. A configuration has been proposed in which a permanent magnet is fixed, an iron piece disposed on the actuator arm is magnetically attracted by a permanent magnet fixed to the housing, and the actuator arm is fixed by a magnetic attractive force of the permanent magnet. In this example, an iron piece arranged on the actuator arm and a permanent magnet fixed to the housing function as a head holding member, and a head holding method using a magnetic attractive force by the permanent magnet is adopted.

  In such a configuration, when the disk drive device is stopped, a current is supplied to the coil of the VCM, the actuator arm is operated to move to a predetermined retracted position, and the iron piece becomes a permanent magnet when approaching the predetermined retracted position. The actuator arm can be fixed in the retracted position after being attracted. In this state, even if an external force is applied, the actuator arm is fixed by the magnetic attraction force, so the data recording area on the recording medium does not move. The data and the actuator are protected from inadvertent movement of the conversion head and the actuator arm (see, for example, Patent Document 1).

  Further, regarding the actuator locking method of the disk drive device having the actuator holding member, the plate spring having the actuator arm holding member similar to the above-described example of the disk drive device having the actuator holding member and further having elasticity And a holding member for the actuator arm composed of a solenoid coil. A leaf spring having elasticity to engage with the actuator in the vertical direction and having stress in the upward direction is moved up and down according to the movement of the iron plunger by supplying current to the solenoid coil, A magnet as a first magnetic field supply means having a first magnetic force is arranged below the plunger, and a VCM yoke as a second magnetic field supply means having a second magnetic force is arranged above the plunger. It has a configuration. When the first current is supplied, the solenoid coil generates a magnetic force that pushes up the plunger to move the leaf spring upward, and a second current different from the first current is generated. When supplied, a magnetic force that pushes down the plunger is generated to move the leaf spring downward. Further, the leaf spring is fixed to the lower side by the first magnetic force of the magnet having a downward magnetic force larger than the upward stress of the leaf spring, and in addition to the upward stress of the leaf spring, the VCM A configuration has been proposed in which the leaf spring is attracted and fixed upward by the second magnetic force of the yoke.

  In such a configuration, during operation of the disk drive device, the plunger is attracted toward the magnet by the first magnetic force, and further, the leaf spring is pressed down by the plunger, and the leaf spring moves the actuator. The leaf spring is fixed so that the unlocked state is fixed at a height that does not hinder the drive, and the actuator is moved to a predetermined lock position (corresponding to the above-mentioned retracted position) when the disk drive device is stopped. A first current that is greater than the difference between the magnitude of the first magnetic force of the magnet and the magnitude of the stress of the leaf spring and that generates an upward magnetic force is supplied to the solenoid coil, The plate spring is moved and fixed so as to be in a locked state in which the plate spring is fixed on the upper side by moving it upward. Here, the current supply to the solenoid coil is supplied only during the transition from the unlocked state to the locked state or from the locked state to the unlocked state, and the leaf spring is fixed to the lower side or the upper side. When the state is in the locked state or the locked state, no current is supplied to the solenoid coil. When the disk drive is stopped, the magnetic attraction force by the iron piece and the permanent magnet and the leaf spring are fixed on the upper side, and the actuator is locked in the retracted position, so that not only in the horizontal direction but also in the vertical direction, The actuator can be fixed, and the movement of the actuator due to impact can be prevented (see, for example, Patent Document 2, Patent Document 3, and Patent Document 4).

  As another example of a disk drive device having an actuator locking mechanism, the actuator is provided so as to be capable of rotating about the actuator swinging shaft and arranged to be opposite to each other across the actuator swinging shaft. There has been proposed a configuration comprising a head arm and a coil arm. The disk drive device with this configuration has the following characteristics. First, (1) the head arm is composed of a carriage arm and a suspension arm, and the suspension arm has a tab formed with a convex portion for receiving in the ramp block, and a head slider having a signal conversion element mounted in the vicinity thereof. Has been implemented. (2) The coil arm having the voice coil mounted on the inner surface includes an outer arm and an inner arm. On the other hand, (3) the ramp block and inertial latch mechanism provided at the retracted position of the actuator are housed inside the enclosure. (4) The lamp block screwed to the enclosure has a plurality of lamps protruding in the horizontal direction from the side of the lamp support, and the lamp has a first slope, a top plane, a second slope, a bottom plane, and a third slope. It has a compound plane that contains it. (5) The inertial latch mechanism includes an inertial lever that can swing about the inertial lever swinging shaft, a latching lever that can swing about the latching lever swinging shaft, and the latch lever at the arm open position. The inertia moment of the inertia lever is larger than that of the latch lever in the inertia moment of the inertia lever and the latch lever around the respective swing shafts. (6) The inertia lever has an inertia formed with a first engagement protrusion for engaging with the latch lever at the first engagement portion and a second engagement protrusion for engagement at the second engagement portion. It has an arm and a balance arm. (7) The latch lever has a latch arm and an auxiliary arm formed with two spring engaging protrusions, positioning protrusions, and latch protrusions that are engaged with the working side end of the spring. Is for determining the actuator release position and actuator latch position of the latch lever, and the latch protrusion engages the tip of the inner arm of the actuator to latch the actuator when the latch lever moves to the actuator latch position. belongs to. Note that (8) the ramp block and the inertial latch mechanism constitute an actuator lock mechanism that functions as a head holding member.

In such a configuration, when the disk drive device is not in operation, the actuator is unloaded to the retracted position, the suspension arm tab is held on the bottom plane of the ramp, and the suspension arm tab against weak impacts. The convex part climbs the second slope or the third slope of the ramp block to attenuate the swing energy of the head arm and suppress the movement of the head arm, and the head arm moves from the retracted position to the disk side or the opposite side. Thus, the ramp block functions as a holding member for the actuator that holds the head arm in the retracted position. In addition, in the operation of the inertial latch mechanism when an impact is applied to the disk drive device when the disk drive device is not operating, the inertia lever and latch are operated when a torque that causes the actuator to swing counterclockwise due to an external impact is applied. Torques that try to rotate counterclockwise about the respective swinging shafts act on the levers respectively. Torques that act on the inertial levers act on the latch levers and the latch levers swinging shafts The inertia lever rotates counterclockwise regardless of the direction of the torque acting on the latch lever if the resultant torque is greater than the resultant torque generated by the torque of the spring that attempts to rotate the latch lever around the first engagement portion. 1 Pull the latch lever with the engaging projection and swing the latch lever counterclockwise. Engage with the tip of the inner arm that has moved from the retracted position, the actuator is latched, and then the tab of the actuator is pushed back to the bottom plane of the ramp block by the action of the ramp ramp second slope, The engagement between the inner arm tip and the latch protrusion is released, and the latch arm returns to the actuator open position by the action of the spring. In addition, when a torque that causes the actuator to swing clockwise due to an impact from the outside acts on the inertia lever and the latch lever, torque that tries to rotate clockwise about the respective swing axis acts on the inertia lever and the latch lever, respectively. In addition to the torque due to the impact, the latch lever is always subjected to a torque that attempts to rotate clockwise around the latch lever swinging shaft by a spring. In the second engagement portion, if the torque acting on the inertia lever is greater than the resultant force of the torque acting on the latch lever and the torque acting on the spring, the latch lever is pushed by the second engagement protrusion in the second engagement portion, and the latch lever The latch projection of the latch arm collides with a crash stop made of an elastic body that restricts the swing range of the actuator, and engages with the tip of the inner arm that has rebounded counterclockwise. In order to increase the torque due to the impact acting on the inertia lever rather than the torque acting upon the latch lever, and to swing in the direction of the torque of the inertia lever due to the impact, Set the moment of inertia to be greater than the moment of inertia of the latch lever. The swinging distance of the latch protrusion from the release point to the latch point, the position of the latch point, and the swing axis from the latch protrusion so that the latch protrusion moves to the latch point before it moves from the retracted point to the latch point. And the like, and the actuator is latched at the retracted position, the actuator is locked, and the head arm and the head slider are prevented from entering the disk arrangement space.
Japanese Patent No. 2803693 (page 3, FIG. 1) Japanese Patent Laid-Open No. 8-221915 (page 4, page 5, FIG. 1, FIG. 2, FIG. 4) JP-A-10-302418 (4th page, 5th page, FIG. 1 and FIG. 2) Japanese Patent Laid-Open No. 2002-260356 (pages 5 to 6, FIG. 1)

  However, in the above-described conventional method for holding an actuator used in a disk drive device having an actuator holding member, when the disk drive device is stopped, an attractive force of an iron piece provided on the actuator arm and a permanent magnet fixed to the housing is obtained. The actuator arm is fixed at the retracted position of the actuator, and the actuator holding method having such a configuration has a relatively high impact resistance against an impact in the same direction as the rotation direction of the actuator. However, there is a problem that the impact resistance against a large impact applied in a short time or an impact having a vertical component with respect to the rotation direction of the actuator is relatively low, and the holding function against the impact cannot be sufficiently exhibited. Also, keep the actuator in the retracted position. To the iron piece and the permanent magnet is required, there is a problem that the number of parts constituting the apparatus is increased cost increase.

  In addition, the above-described conventional actuator holding method is configured to hold the actuator at the retracted position so that the actuator at the retracted position does not move to the data recording area of the recording medium when a relatively large impact is applied. In particular, in an example in which an actuator holding member comprising a locking means and a solenoid coil is provided, an iron piece provided in the actuator arm, a permanent magnet provided in the housing, a leaf spring for gripping the actuator The actuator is held by a magnet for fixing the leaf spring to the lower side, a plunger for moving the leaf spring up and down, and a solenoid coil for moving the plunger up and down. Moved to the retreat position The plate spring is moved upward in accordance with the vertical movement of the plunger, the plate spring is locked, and the actuator is locked in the retracted position, and is resistant to a relatively large impact. In order to keep the leaf spring locked when it receives a very large impact in the same direction as the movement of the plunger, the stress on the upper side of the leaf spring and the second magnetic force of the VCM yoke are It is necessary to set a value that can withstand the impact. Therefore, the plunger is moved downward against the large resultant force of the stress on the upper side of such a leaf spring and the second magnetic force of the VCM yoke, In order to bring the spring into the unlocked state, it is necessary to generate a large magnetic force by passing a large current through the solenoid coil. There is a problem that it is difficult to reduce the size of the disk drive device because there is a need for a space for disposing each component that constitutes the holding member of the actuator for locking the eta in the retracted position. In order to configure the mechanism, many parts are required, which causes a problem of increasing the cost of the apparatus.

  In addition, in a disk drive device comprising a head arm and a coil arm that are provided so that the actuator can be rotated about the swing shaft and arranged on opposite sides of the swing shaft, The lever, latch lever, and spring constitute an inertial latch mechanism. When a relatively large impact is received when the disk drive device is not operating, the inertial lever rotates and depends on the direction of the torque acting on the latch lever. The latch lever is rotated counterclockwise, and the latch projection of the latch arm engages with the inner arm tip of the coil arm of the actuator that has moved from the retracted position to latch the actuator. Therefore, the moment of inertia of the inertia lever is larger than the moment of inertia of the latch lever. It is that is Ku set. In the actuator locking mechanism having such an inertial latch mechanism, the dead zone area for impact can be made extremely small, and the reliability as the actuator locking mechanism is improved. In addition, many parts are required, and a space for arranging these parts is also required, which causes an increase in cost of the apparatus and an obstacle to miniaturization.

  SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a head holding member and a head holding method for an actuator having a very simple configuration and a very high impact resistance, and a disk device including the same. .

In order to achieve the above object, the head holding member of the present invention retracts the tab portion formed at one end of the head support arm constituting the actuator when the actuator is unloaded in response to a disk device operation stop command. A head holding member that guides to a position and holds the tab portion in the retracted position, wherein the retracted position holds the tab portion and a predetermined angle with respect to the head holding plane on the loading side of the head holding plane And a third slope formed on the unloading side of the head holding plane with a predetermined angle with respect to the head holding plane. Yes. Further, the predetermined first angle θ ₁ formed by the first step side surface with respect to the head holding plane is 90 ° ≦ θ ₁ ≦ 101 °.
The predetermined second angle θ ₂ formed by the third inclined surface with respect to the head holding plane is 90 ° ≦ θ ₂ ≦ 169 °
And a configuration in which the width of the head holding plane is larger than the width of the tab portion of the head support arm in a direction perpendicular to the rotation center of the rotation shaft of the actuator. It may be.

  With these configurations, when the power is stopped during the operation of the magnetic disk device, or when an emergency stop command is input to the magnetic disk device, the tab portion of the head support arm is ramped when the actuator is moved to the retracted position. By making contact with the third inclined surface of the head portion, the energy of the collision between the tab portion and the third inclined surface is suppressed, and damage caused to the tab portion of the head support arm or the third inclined surface of the ramp portion is suppressed. Therefore, a highly reliable head holding member can be realized.

  The head holding member of the present invention has a configuration in which the head holding plane and the first step side surface, and the head holding plane and the third inclined surface are continuous by a curved surface having a predetermined radius of curvature. Further, the radius of curvature of the curved surface connecting the head holding plane and the first step side surface and the head holding plane and the third inclined surface is substantially the same as or larger than the outer peripheral surface of the tab portion formed at the tip of the head support arm. It is also possible to have a configuration in which the arc is a circle.

  With these configurations, the contact surface between the tab portion and the guide surface of the lamp portion is enlarged, the contact stress due to the pressing of the tab portion is reduced, and the wear of the guide surface of the lamp portion can be reduced. Reliability can be improved.

  In order to achieve the above object, the head holding method of the present invention includes a recording medium rotatably disposed around a rotation axis, a head and a tab at one end, and a position away from the rotation axis. A head support arm that is rotatable around a first rotation axis parallel to the rotation axis by a first bearing disposed on the head, and disposed between the head and the first bearing, A second bearing rotatable around a second rotation axis perpendicular to the longitudinal center line; and a second bearing on the second rotation axis and contacting the head support arm or the second bearing. A method of holding a head in a disk device, comprising: at least one contact portion; a leaf spring portion connected to the head support arm and the second bearing portion; and a ramp portion that holds the tab portion when the head support arm is retracted. The third inclined surface with which the tab portion abuts, and the tab portion from the retracted position to the recording medium. When the tab portion moves to the retracted position in the ramp portion in which the first step side surface that prevents the head portion from moving in the direction and the head holding plane that holds the tab portion in the retracted position is formed, the radial direction of the recording medium The force in the direction perpendicular to the radial direction and the urging force of the leaf spring portion are applied to the head support arm to move the head support arm in the radial direction of the recording medium, and at least the leaf spring portion of the force acting on the head support arm. This is a head holding method in which the tab portion is brought into contact with the third inclined surface of the ramp portion by the urging force and then held on the head holding plane serving as a retracted position of the tab portion. In addition, the head support arm has a voice coil connected to the head support arm via a voice coil holder, and the head support arm is driven around the first rotation axis by supplying current to the voice coil and driving it. It may be a head holding method of swinging.

  By these methods, when the power supply is stopped during the operation of the magnetic disk device, or when an emergency stop command is input to the magnetic disk device, the energy of the collision between the tab portion and the third inclined surface is reduced, and the head is supported. Damage to the third slope of the tab portion of the arm or the ramp portion can be suppressed, and the head slider is disposed even when a large external shock is applied when the magnetic disk device is stopped (not operating). In addition, the tab portion of the head support arm does not separate from the head holding plane of the ramp portion, which is the retracted position, and a head holding method that enables stable head holding can be realized.

  The head holding method of the present invention is a head holding method that has a crash stop that abuts the voice coil holder, and the crash stop restricts excessive swinging of the head support arm. In addition, when the tab portion moves to the retracted position, the head holding method in which the voice coil holder abuts against the crash stop before the tab portion abuts against the third inclined surface in the course of the retract until the tab portion is retained at the retracted position. It may be.

  By these methods, when the power supply is stopped during the operation of the magnetic disk device, or when an emergency stop command is input to the magnetic disk device, the energy of the collision between the tab portion and the third slope is further reduced, and the head It is possible to further reduce damage to the tab portion of the support arm or the third slope of the ramp portion, to improve the durability of the ramp portion that is the head holding member, and when the magnetic disk device is stopped (not operating). Even when a large impact is applied from the outside, the tab portion of the head support arm on which the head slider is disposed does not detach from the head holding plane of the ramp portion, which is the retracted position, enabling stable head holding. A head holding method can be realized.

In order to achieve the above object, the disk device of the present invention includes a recording medium rotatably disposed around the rotation axis, a head and a tab at one end, and a position away from the rotation axis. A head support arm that is rotatable around a first rotation axis parallel to the rotation axis by a first bearing disposed on the head, and disposed between the head and the first bearing, A second bearing rotatable around a second rotation axis perpendicular to the longitudinal center line; and a second bearing on the second rotation axis and contacting the head support arm or the second bearing. At least one contact portion, a leaf spring portion that connects the head support arm and the second bearing, and a ramp portion that holds the tab portion when the head support arm is retracted. Head holding plane for holding the recording medium and the recording medium area side of the recording medium with respect to the head holding plane A first step side surface formed at a predetermined angle with respect to the head holding plane, and a predetermined angle with respect to the head holding plane on the opposite side of the recordable area of the recording medium with respect to the head holding plane. A ramp portion formed with a third inclined surface, and when the tab portion moves to the retracted position, the force in the radial direction of the recording medium and the direction perpendicular to the radial direction and the leaf spring portion The urging force is applied to the head support arm to move the head support arm in the radial direction of the recording medium. Of the forces acting on the head support arm, at least the urging force of the leaf spring portion causes the tab portion to 3 is configured to be held by a head holding plane which is a retracted position after abutting against the slope 3. The second bearing is a pivot bearing having a pivot as a contact point, the pivot is a cone or the apex of a pyramid, and the second bearing has one point of a curved surface to be contacted as a contact point. The head support arm has a voice coil connected to the head support arm via a voice coil holder, and supplies current to the voice coil. The head support arm may be configured to swing around the first rotation axis by being driven. Furthermore, when the rotation of the recording medium is stopped, the tab portion of the head support arm has a pressing force that presses the head holding plane of the ramp portion, and the tab portion when the tab portion slides on the first step side surface; When the friction coefficient between the first step side surface is μ ₁ and the friction coefficient between the tab portion and the third slope when the tab portion slides on the third slope is μ ₂ , the head is held. The predetermined first angle θ ₁ formed by the first step side surface with respect to the plane and the predetermined second angle θ ₂ formed by the third inclined surface with respect to the head holding plane are respectively defined with respect to the head holding plane. 90 ° ≦ θ ₁ ≦ (90 ° + tan ⁻¹ μ ₁ )
90 ° ≦ θ ₂ ≦ (180 ° −tan ⁻¹ μ ₂ )
And a predetermined first angle θ ₁ formed by the first step side surface with respect to the head holding plane and a predetermined angle formed by the third inclined surface with respect to the head holding plane. The second angle θ ₂ is 90 ° ≦ θ ₁ ≦ 101 ° with respect to the head holding plane.
90 ° ≦ θ ₂ ≦ 169 °
You may have the structure formed so that it might become. In addition, the ramp portion is disposed near the outer periphery of the recording medium, and the first magnet is disposed on the opposite side of the recording medium side with respect to the head support arm so as to face the voice coil. The second magnet may be disposed in the vicinity of the rotation center of the recording medium, and the second magnet may be disposed on the recording medium side with respect to the head support arm so as to face the second voice coil.

  With these configurations, when the power is stopped during the operation of the magnetic disk device, or when an emergency stop command is input to the magnetic disk device, the energy of the collision between the tab portion and the third slope is suppressed, and the head support Damage to the tab portion of the arm or the third inclined surface of the ramp portion can be further reduced, and the durability of the ramp portion, which is the head holding member, can be improved, and externally when the magnetic disk device is stopped (not operating). Even when subjected to a large impact from the head, the tab portion of the head support arm on which the head slider is disposed does not separate from the head holding plane of the ramp portion which is the retracted position, enabling stable head holding, At the start of the operation of the disk device, a repulsive drive torque is generated between the voice coil and magnet constituting the VCM, and the head support arm is moved. The torque that tries to rotate in the direction perpendicular to the surface of the recording medium works, the force that moves the tab portion of the head support arm upward is generated, and the force that rotates the actuator around the rotation axis is also generated, The actuator can be detached from the retracted position and easily moved in the direction on the surface of the recording medium, and a disk device that has high reliability and durability and realizes stable head holding at low cost can be realized.

  In addition, the disk device of the present invention has a crash stop that contacts the voice coil holder, and the crash stop has a configuration that restricts excessive swinging of the head support arm. In addition, when the tab portion moves to the retracted position, the voice coil holder abuts against the crash stop before the tab portion abuts against the third slope until the tab portion is held at the retracted position. You may have a structure.

  With these configurations, when the power supply is stopped during the operation of the magnetic disk device, or when an emergency stop command is input to the magnetic disk device, the voice coil holder and the crash stop are To absorb a part of the kinetic energy of the actuator, and therefore, the energy of the collision between the tab portion and the third slope can be kept small, and the third portion of the tab portion or the ramp portion of the head support arm can be suppressed. Damage to the slope can be further reduced, and the durability of the lamp portion, which is a head holding member, can be improved, and an excellent disk device with high reliability and durability can be realized.

  The head holding member of the present invention has a tab portion formed at one end, and a voice coil holder to which a voice coil and a balancer are fixed is fixed to a head support arm to which a head slider is attached via a gimbal mechanism. The tab support side of the head support arm is such that the two pivots come into contact with the upper surface of the head support arm and the line connecting the contact points of the two pivots of the pivot bearing and the upper surface of the head support arm is a fulcrum. And a flange of a cylindrical bearing portion with a hollow collar, which is elastically connected by a leaf spring portion which is an elastic means bent in two stages so that a stress for pushing down the recording medium acts on the surface side of the recording medium. An actuator having a structure in which a pivot bearing and a leaf spring portion are sandwiched by a nut, and a voice coil constituting the actuator is sandwiched The actuator can be rotated around the rotation axis by a magnet fixed to the upper yoke on the side opposite to the recording medium side and a voice coil motor (VCM) provided with the lower yoke on the recording medium side. In the disk device, when the stop command is instructed to the disk device, the head holding plane which is the retracted position of the actuator is the guide surface of the upper surface of the ramp portion that guides the tab portion of the head support arm constituting the actuator to the retracted position. The first step side surface and the third inclined surface respectively having a predetermined angle with respect to the head holding plane are formed on both sides of the head, and when an emergency stop command is instructed to the disk device for some reason, the tab of the head support arm After the part comes into contact with the third inclined surface, the tab part reaches the head holding plane, and is on the head holding plane which is the retracted position. A head holding member configured to hold the tab portion.

  With such a configuration of the head holding member, the tab portion of the head support arm is guided by the ramp portion constituting the head holding member at the time of emergency stop, and the tab portion is moved when moving to the head holding plane which is the retreat position. The impact caused by the abutment of the ramp portion received by the tab portion can be suppressed to a small amount by being brought into contact with the third inclined surface, and therefore, the damage caused to the ramp portion or the tab portion due to the tab portion abutting against the ramp portion is suppressed. be able to.

  Further, the disk device of the present invention has a pivot coil bearing in which a voice coil holder to which a voice coil and a balancer are fixed is fixed to a head support arm on which a tab portion is formed at one end and a head slider is attached via a gimbal mechanism. The two tabs of the head support arm are in contact with the upper surface of the head support arm, and the tab portion of the head support arm is a line connecting the contact points of the two pivots of the pivot bearing and the upper surface of the head support arm. And a flange of a cylindrical bearing portion with a hollow collar, which is elastically connected by a leaf spring portion which is an elastic means bent in two stages so that a stress that pushes the side toward the surface side of the recording medium acts An actuator having a structure in which a pivot bearing and a leaf spring part are sandwiched by a nut, and a voice coil that constitutes the actuator A voice coil motor (VCM) for disposing the magnet fixed to the upper yoke on the side opposite to the recording medium side and the lower yoke on the recording medium side so that the actuator can rotate about the rotation axis; A ramp block, which is a head holding member, formed with a first step side surface and a third inclined surface respectively having a predetermined angle with respect to the head holding plane on both sides of the head holding plane which is a retracted position of the actuator; It is a head holding method in which the actuator is moved to a retracted position by a configuration consisting of a crash stop for restricting excessive rotation, and the tab portion of the head support arm constituting the actuator is held at the retracted position. A disk apparatus having a configuration having a head holding method.

  By adopting such a head holding method and disk device configuration, when the disk device is stopped, when the tab portion is held on the head holding plane which is the retracted position, even if a large impact is applied from the outside. The first step side surface formed on the recording medium side of the head holding plane of the ramp portion, which is the retracting position of the actuator, and the crush stop that prevents excessive rotation of the actuator to the side away from the recording medium cause the rotation of the actuator. The movement of the tab portion of the head support arm due to the rotation around the movement axis is prevented, and the tab portion does not detach from the recess formed by the first step side surface, the head holding plane, and the third inclined surface. The tab portion is held on the head holding plane, the actuator moves to the recording medium side, collides with the recording medium, and the recording medium Damage to the surface, damage to the components that make up the actuator, or the head slider may come into contact with and pick up from a disk that has stopped rotating, causing damage to the disk during restart, or The occurrence of a serious failure such as inability to restart can be prevented. On the other hand, at the start of the operation of the disk device, a line connecting each contact point between the two pivots of the pivot bearing and the upper surface of the head support arm by a repulsive driving torque generated between the voice coil and the magnet in the VCM is used as a fulcrum. The head support arm is rotated in the direction perpendicular to the surface of the recording medium, and the force to push the tab portion upward is activated. At the same time, the force to rotate the actuator around the rotation axis is activated. It is possible to start the recording / reproducing operation of the disk device by moving the actuator away from the head holding plane which is the retracted position and performing the loading operation so as to move in the direction above the surface of the recording medium. Further, when the disk device is in an emergency stop, the tab portion of the head support arm is guided by the ramp portion constituting the head holding member, and the tab portion is brought into contact with the third inclined surface when moving to the head holding plane which is the retracted position. Thus, the impact due to the contact of the lamp portion received by the tab portion can be suppressed to a small level, and it is possible to prevent the lamp portion or the tab portion from being fatally damaged when the tab portion contacts the lamp portion.

  Therefore, even when the disk device is subjected to a very large impact from the outside when the disk device is stopped, a very stable actuator head holding method having high impact resistance can be realized. The disk device having such a head holding method does not require many individual members to hold the actuator, is inexpensive, requires a small space for holding the head, is suitable for downsizing, and Thus, it is possible to realize an excellent disk device having very high impact resistance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Further, a magnetic disk device will be described as an example of the disk device.

(Embodiment)
1 to 11 are diagrams for explaining a head holding member and a head holding method of an actuator provided in a disk device according to an embodiment of the present invention. FIG. 1 is a plan view showing a schematic configuration of a main part of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a side view showing a configuration of an actuator included in the magnetic disk device shown in FIG. 1, and FIG. 4 is an exploded perspective view showing the configuration of the actuator provided in the magnetic disk device shown in FIG. 4, FIG. 4 is a plan view showing the vicinity of the ramp block when the actuator provided in the magnetic disk device shown in FIG. 1 is in the retracted position, and FIG. FIG. 6A is a cross-sectional view taken along the line BB showing the ramp portion, the tab portion, and the recording medium in FIG. 4, and FIG. 6B is a graph showing the relationship between the drop height h of the tab portion and the collision speed v of the tab portion against the ramp portion, and FIG. 6C is the current supplied to the voice coil and the head. Graph showing the relationship between impact velocity v ₂ of the collision speed v ₁ and the third slope in lifting plane shown in FIG. 6 (d) the tab portion in the power supply stop or emergency stop operation of the magnetic disk apparatus and the ramp portion 7 (a) to 7 (e) are cross-sectional views showing the shapes of various tab portions, and FIG. 8 is an attempt to rotate the actuator to the recording medium side. FIG. 9 is a partially enlarged view showing the vicinity of the head holding plane of the lamp portion, and FIG. 10 (a) is constant. FIG. 10B is a graph showing the relationship between the position of the VCM and the rotation torque of the actuator when the current of the current is supplied, and FIG. 10B is a graph showing the relationship between the position of the VCM and the repulsive driving torque acting on the VCM during the load operation. Is the tab part that presses the side of the first step FIG. 12 is a perspective view showing a schematic configuration of the main part of another magnetic disk device according to the embodiment of the present invention, and FIG. 13 is another diagram in the embodiment of the present invention shown in FIG. It is a disassembled perspective view which shows the structure of the actuator with which a magnetic disc apparatus is provided. 1 and 12, the upper lid is removed and the upper yoke is omitted.

  In FIG. 1, a recording medium 4 having a recording medium layer formed on the surface thereof is placed on a rotor hub portion 3 fixed to a rotating shaft 2 of a spindle motor (not shown) that rotates around a rotation center 1. Yes. On the other hand, a tab portion 8a is formed at one end of the actuator 7 which is a signal conversion element swinging arm pivotally supported around a rotation shaft 5 via a bearing 6, and a tab portion 8a. A head slider 9 on which a magnetic head (not shown) as a signal conversion element is mounted via a gimbal mechanism (not shown) on the rotating shaft 5 side, and a voice coil 10 is arranged on the other end. It rotates around the rotation axis 5 in a direction parallel to the surface of the recording medium 4. Further, an upper yoke 12 having a magnet 11 fixed thereto is located above the voice coil 10 so as to face the voice coil 10, that is, on the side opposite to the recording medium 4 with respect to the actuator 7 provided with the voice coil 10. Is attached to a housing (not shown). A lower yoke 13 is attached to the chassis or other casing below the voice coil 10 so as to face the voice coil 10 with the voice coil 10 interposed therebetween. A voice coil motor (hereinafter referred to as VCM) 19 is configured by the voice coil 10, the magnet 11 fixed to the upper yoke 12 facing the voice coil 10, and the lower yoke 13. In addition, a lamp block 15 which is a head holding member having a lamp portion 14 provided with a guide portion so as to contact the tab portion 8a provided on the actuator 7 and guide the actuator 7 up and down is provided in a chassis or other housing. Installed on the body. By supplying a current to the voice coil 10 facing the magnet 11, the VCM 19 is activated and the actuator 7 is rotated in the radial direction of the recording medium 4. During the operation of the magnetic disk device, the actuator 7 rotates around the rotation shaft 5 and moves on the data recording area of the rotating recording medium 4, and when the magnetic disk device is not operating, the actuator 7 is rotated clockwise. And the actuator 7 is rotated to a predetermined position of the lamp portion 14 which is a retracted position. As is well known, the actuator 7 prevents excessive oscillation in the clockwise direction (the direction opposite to the rotation center 1 of the recording medium 4) or the counterclockwise direction (the direction of the rotation center 1 of the recording medium 4). For this purpose, a crash stop 16 and a crash stop 17 are provided on the chassis or the casing or other structural members. The crush stop 16 is configured to abut against the actuator 7 so as to prevent the actuator 7 from rotating from the ramp portion 14 in the clockwise direction.

  Here, the magnet 11 fixed to the upper yoke 12 facing the voice coil 10 constituting the VCM 19 fixed to the actuator 7 will be described. In FIG. 1, when the actuator 7 rotates and the magnetic head (not shown) is positioned at the center position 18 of the recordable area Ra of the recording medium 4, the voice coil 10 with respect to the position of the actuator 7 at this time. The magnet 11 is magnetized at a position corresponding to the center line 10a in the rotational circumferential direction so that the boundary between the N pole and the S pole of the magnet 11 coincides. At the same time, the radial direction of the rotating shaft 5 of the magnet 11 corresponding to the operating range of the voice coil 10 when the actuator 7 is operating in the recordable area Ra of the recording medium 4 (that is, the longitudinal direction of the actuator 7). The shape of the magnet 11 is set and formed so that the width of the magnet 11 in the radial direction of the rotating shaft 5 when the actuator 7 is at the retracted position is larger than the width at, and is fixed to the upper yoke 12. .

  Next, the configuration of the actuator 7 will be described with reference to FIGS.

  2 and 3, a head slider 9 on which a magnetic head (not shown) is mounted via a gimbal mechanism 21 is arranged on a head support arm 8 having a tab portion 8a on one end and a hole 8b on the other end. The head support arm unit 22 is configured. When the dimple 8c is provided on the lower surface of the head support arm 8 so as to contact the vicinity of the center portion of the head slider 9 and the head slider 9 is attached via the gimbal mechanism 21, the dimple 8c is attached to the gimbal mechanism 21 or the head. The recording medium (see FIG. 3) of the head slider 9 during operation of the magnetic disk device is brought into contact with the substantially central portion of the upper surface of the slider 9 (the surface opposite to the surface on which the magnetic head is mounted). It is possible to flexibly follow unnecessary vibrations in the roll or pitch direction with respect to 4 (not shown). Further, the voice coil 10 is attached to a voice coil holder 23 having a hole 23 a, and a balancer 24 is fixed to the opposite side of the hole 23 a across the voice coil 10 to constitute a voice coil portion 25. Further, the voice coil unit 25 is fixed to the head support arm unit 22 to constitute an actuator subunit 26. The head support arm unit 22 and the voice coil unit 25 are described as separate members. However, the head support arm unit 22 and the voice coil unit 25 are not limited to this and may be integrated into one unit.

On the other hand, a pair of pivots 29a and 29b, in which one end of a leaf spring portion 27, which is an elastic means bent in two stages in a substantially annular shape in a substantially Z shape, serves as a joint portion via a semi-annular spring fixing member 28; It is fixed to a pivot bearing 29 having a hole 29c. Further, the leaf spring portion 27 is passed through the hole portion 8 b of the head support arm 8, and a pair of pivots 29 a and 29 b serving as a joint portion of the pivot bearing portion 29 are brought into contact with the upper surface of the head support arm 8 so that the leaf spring portion 27. The other end of the head is fixed to the lower surface of the head support arm 8, and the actuator subunit 26 and the pivot bearing portion 29 having the head support arm 8 as constituent elements via the leaf spring portion 27 and a pair of pivots 29 a and 29 b are elastic means. The contact points P ₁ and P ₂ of the pair of pivots 29 a and 29 b that are elastically connected by a certain plate spring portion 27 and serve as a joint portion of the pivot bearing portion 29 and the upper surface of the head support arm 8 are used as fulcrums. The leaf spring portion 27 acts so as to push down the tab portion 8a side of the head support arm 8 constituting the actuator subunit 26. Actuator subunit 26 constitute an actuator arm 30 by the plate spring 27, the spring fixing member 28 and the pivot bearing unit 29.

Therefore, during the operation of the magnetic disk device, the load load of the head slider 9 when the head slider 9 attached to the head support arm unit 22 via the gimbal mechanism 21 is floating with respect to the surface of the recording medium 4 is: Compression in the direction of the recording medium 4 as a reaction force due to the deformation of the leaf spring portion 27 with respect to the head support arm unit 22 at the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b serving as the joint portions of the pivot bearing portion 29 The head slider 9 is lifted by the relationship between the biasing force in the direction of the recording medium 4 applied to the head slider 9 and the levitation force in the opposite direction to the head slider 9 and deforms the leaf spring portion 27 to Recording and reproduction of the magnetic disk device is performed while maintaining a certain gap between the recording medium 4 and the recording medium 4.

  Furthermore, a flange 31a having an outer diameter larger than the inner diameter of the hole 29c of the pivot bearing portion 29 on one end side, and a screw portion 31b having an outer diameter smaller than the inner diameter of the hole portion 29c of the pivot bearing portion 29 on the other end side; A hollow flanged cylindrical bearing portion 31 comprising a cylindrical portion 31c having an outer diameter that fits with the hole portion 29c of the pivot bearing portion 29 between the flange 31a and the threaded portion 31b is replaced with a hole portion 29c of the pivot bearing portion 29. The spring fixing member 28 is penetrated through the semi-annular inner side, the leaf spring part 27 in the annular inner side, and the hole 23 a of the voice coil holder 23. Also, it has an inner diameter that fits into the cylindrical portion 31c from the opposite side of the flange 31a and an outer diameter that penetrates the hole portion 23a of the voice coil holder 23, and is substantially the same as the portion that is in contact with the spring fixing member 28. A hollow collar 32 provided with a semi-annular projecting portion 32a having a shape is inserted into the cylindrical portion 31c of the bearing portion 31 so that the projecting portion 32a is on the flange 31a side of the bearing portion 31. The upper surface 32b of the protruding portion 32a is brought into contact with the substantially annular flat portion of the leaf spring portion 27 fixed to the spring fixing member 28. In this way, the collar 32 is sandwiched by the flange 31a and the nut 33 of the bearing 31 together with the flat portion of the spring fixing member 28 and the flat spring portion 27 fixedly contacting the spring fixing member 28, and the actuator arm 30, bearing The actuator 7 is integrally configured by the portion 31, the collar 32 and the nut 33.

Next, the positions of the pair of pivots 29a and 29b provided on the pivot bearing portion 29 constituting the actuator 7 will be described. Each line connecting the contact point P ₁ and the contact point P ₂ the pivot 29a and the pivot 29b is in contact with the upper surface of the head support arm 8 through a shaft center of the rotation axis 5 of the actuator 7 shown in FIG. 1, and, The head support arm 8 constituting the actuator 7 shown in FIG. 1 is formed so as to be perpendicular to the longitudinal center line 8d. Note that the contact point P ₁ and the contact point P ₂ are arranged so as to be symmetrical with respect to the axis of the rotation shaft 5 of the actuator 7, and are in the line connecting the contact point P ₁ and the contact point P _2. It is desirable to make the point substantially coincide with the axis of the rotation shaft 5. According to this structure, the actuator sub-unit 26 of the recording medium around a line connecting the contact point P ₁ and the contact point P ₂ of the pivot 29a and the pivot 29b of the joint portion of the pivot bearing part 29 which constitutes the actuator 7 The head support arm 8 constituting the actuator subunit 26 is rotated counterclockwise by the elastic force of the leaf spring portion 27 and mounted on the head support arm 8. The head slider 9 side is biased toward the recording medium 4. Incidentally, the line connecting the contact point P ₁ and the contact point P ₂ is, has been described as passing through the axis of the pivot shaft 5 of the actuator 7 shown in FIG. 1, not to any limited thereto, the contact point P ₁ and it may be in a line perpendicular to the plane line connecting the contact point P ₂ is formed by a longitudinal center line 8d of the axis and the head support arm 8 of the rotary shaft 5.

Further, the position of the center of gravity of the actuator 7 is made to substantially coincide with the midpoint of the line connecting the contact points P ₁ and P ₂ of the pivot bearing portion 29 that contacts the upper surface of the head support arm 8 constituting the actuator subunit 26. The mass (weight) of the balancer 24 is set, and the balancer 24 is fixed to one end of the voice coil holder 23 constituting the voice coil unit 25. That is, when the actuator 7 is configured, the position of the center of gravity of the actuator 7 is configured to substantially coincide with the axis of the rotation shaft 5 of the actuator 7. Approximately, the position of the center of gravity of the actuator subunit 26 may be substantially coincident with the axis of the rotating shaft 5 as described above, and the deviation from the position of the center of gravity of the actuator 7 is a problem in practice. It is a thing which should not be. Although the balancer 24 is described as being fixed to one end of the voice coil holder 23, the balancer 24 is provided on the head slider 9 side of the head support arm unit 22 depending on the mass (weight) distribution of each component constituting the actuator 7. There are cases where it is necessary.

  By configuring the actuator 7 as described above, the head support arm 8 constituting the actuator 7 can be formed of a highly rigid material, so that the impact resistance against a large external impact is improved, and the head The resonance frequency of the support arm 8 can be increased. Therefore, the vibration mode that has been a problem in the past does not occur and the settling operation is not necessary, so that the actuator 7 can be rotated and positioned at a high speed, and the access speed of the magnetic disk device can be improved. . Further, the leaf spring portion 27 that is an elastic means is not integrally formed with the head support arm 8 so as to be a single member, but is provided as a separate member independent of the head support arm 8. The conflicting demands of increasing the load applied to the head slider 9, increasing the flexibility, and further increasing the rigidity of the structure can be realized independently as actions of the individual components. Therefore, the design of the actuator 7 is simplified, and the degree of freedom in design can be greatly expanded. Moreover, unlike the conventional head support arm, it is not necessary to form a very precise leaf spring part, and the head support arm can be easily formed as compared with the conventional head support arm. The thickness, material, and the like of 27 can be set independently, and the strength and spring constant of the leaf spring portion 27 can be set to predetermined values as desired.

  When the magnetic disk device is stopped, a so-called load / unload method (sometimes abbreviated as U / UL method) in which the actuator 7 rotates around the rotation shaft 5 and moves to the outside of the recording medium 4. As is well known, the ramp portion 14 for guiding the actuator 7 to the retracted position in the unloading operation at this time will be described.

  4 and 5, the lamp block 15 that is a head holding member attached to the chassis or other casing has a lamp portion 14 that protrudes horizontally from the side surface of the lamp attachment portion 41. A part of the recording medium 4 is attached so as to overlap with the upper surface of the recording medium 4 in the axial direction of the rotational center (not shown) of the recording medium 4. The ramp portion 14 has an upper surface 42 including a first inclined surface 14a, a first plane 14b, a second inclined surface 14c, a first step side surface 14d, a head holding plane 14e, and a third inclined surface 14f. Thus, the tab 7 a of the head support arm 8 constituting the actuator 7 described above guides the actuator 7 while coming into contact with the upper surface 42 of the ramp portion 14. Note that the second inclined surface 14c is not necessarily provided.

The first plane 14b and the head holding plane 14e in the ramp unit 14 are planes substantially parallel to a plane perpendicular to the rotation axis of the actuator. The first step side surface 14d adjacent to the loading side of the actuator 7 with respect to the head holding plane 14e is a plane having an angle of α ₁ ° on the loading side from the plane perpendicular to the head holding plane 14e. The height in the axial direction is at least larger than the height in the axial direction of the rotation shaft of the tab portion 8a of the head support arm 8, and is formed to be continuous with the second inclined surface 14c. The third inclined surface 14f adjacent to the unloading side of the actuator 7 with respect to the head holding plane 14e is a plane having an angle of α ₂ ° on the unloading side with respect to a plane perpendicular to the head holding plane 14e. The shaft 5 is formed so that the height in the axial direction of the shaft 5 is at least larger than the height in the axial direction of the rotary shaft 5 in the tab portion 8a of the head support arm 8 and is continuous with the second plane 14g. Has been.

  When a stop command is input to the magnetic disk device, a current is supplied to the VCM 19 while the recording medium 4 is rotated, and the actuator 7 is rotated clockwise to move it outside the recording medium 4. In the vicinity of the outer peripheral portion of the recording medium 4, the tab portion 8 a of the head support arm 8 at one end of the actuator 7 abuts on the first inclined surface 14 a of the ramp portion 14, and further, the actuator 7 is rotated clockwise. The first inclined surface 14a, the first flat surface 14b, the second inclined surface 14c, the first step side surface 14d, and the head holding flat surface 14e of the ramp portion 14 are sequentially guided. The rotation of the actuator 7 stops on the head holding plane 14e. The head holding plane 14e is a retracted position of the actuator 7. The rotation of the recording medium 4 stops while the actuator 7 is guiding the upper surface 42 of the ramp portion 14 or after being guided to the retracted position.

Here, the relationship between the tab portion 8a and the ramp portion 14 of the actuator 7 when the stop command is input to the magnetic disk device and the rotation of the actuator 7 stops will be described. When a stop command is input, the VCM 19 rotates the actuator 7 in the clockwise direction. The tab portion 8a of the actuator 7 is guided so as to be separated from the surface of the recording medium 4 while coming into contact with the upper surface 42 of the ramp portion 14, and reaches the head holding plane 14e. At this time, a magnetic force according to Fleming's right-hand rule acts between the voice coil 10 to which current is supplied to rotate the actuator 7 clockwise and the magnet 11 fixed to the upper yoke 12, and the voice coil The electromagnetic force between the voice coil 10 of the actuator 7 and the magnet 11 depends on the direction of the current to 10 and the polarity of the magnet 11 facing the voice coil 10 of the actuator 7 having the tab portion 8 a on the upper surface 42 of the lamp portion 14. work, the line connecting the contact point P ₁ and the contact point P ₂ of the pivot 29a and the pivot 29b of the pivot bearing 29 as a fulcrum (supporting shaft) and the resulting torque to be rotated the actuator 7 around the line, While the tab portion 8 a of the actuator 7 presses the upper surface 42 of the ramp portion 14, the tab portion 8 a It will be guided upwards.

Therefore, at the moment when the tab portion 8a passes the second inclined surface 14c of the ramp portion 14, the actuator 7 has a voice coil 10 and a magnet in a direction perpendicular to the surface of the recording medium 4, as shown in FIG. 11, a rotating torque t ₁ due to an electromagnetic force acting between 11 (this electromagnetic force is a force to rotate toward the recording medium 4) and a rotating torque t ₂ due to the urging force of the leaf spring portion 27. When, the resultant force torque T ₁ of the the rotational torque t ₃ when you try to rotate the actuator 7 about the pivot shaft 5 to the opposite side acts from the recording medium 4 side by the VCM 19. 6D, when the current supply to the voice coil 10 is stopped to stop the rotation of the actuator 7, the actuator 7 is rotated by the urging force of the leaf spring portion 27. The resultant torque T ₂ with each inertial rotation torque due to the inertia of each of the torque t ₂ ′ and the rotation torque t ₃ ′ by the VCM 19 acts. Therefore, in the state tab portion 8a of the actuator 7 having an energy by force torque T ₁ or T ₂ of the these rotational torque, a first step side surface 14d in the lamp unit 14, the head holding plane 14e and the third slope It enters the recess 51 formed by 14f.

When a normal stop command is input during the operation of the magnetic disk device, the current supplied to the voice coil 10 of the actuator 7 is controlled according to the position of the tab portion 8a. when 8a enters the force torque T ₁ or T ₂ of the rotational torque is extremely small, the tab portion 8a that has entered the recess 51 in contact with the head holding plane 14e is retracted positions, the head holding plane 14e The tab portion 8a is held on the top.

On the other hand, when the power supply is stopped during the operation of the magnetic disk device, the maximum current is supplied to the voice coil 10 using an internal capacitor (not shown) provided in the disk device, and the actuator 7 is forced to the retracted position at the maximum speed. Try to unload to. Furthermore, when the retracting operation of the actuator 7 is difficult to control, or when an accident due to an external factor such as excessive vibration or shock or some internal factor occurs and an emergency stop command is input to the magnetic disk device, The maximum current is supplied to the voice coil 10 and the actuator 7 is unloaded at the maximum speed to the retracted position. At this time, the current supplied to the voice coil 10 is controlled and disconnected in a time sufficient to save, and since the current supplied to the voice coil 10 is not controlled, a large current flows, and the head force torque T ₁ which tab portion 8a of the supporting arm 8 acts on the tab portion 8a when entering into the recess 51 is large, the tab portion 8a of the head supporting arm 8 that has entered the recess 51 a third inclined surface forming the recess 51 It collides with 14f, and further collides with the crash stop 16, and the rotation of the actuator 7 is stopped. In other words, since the ramp portion 14 receives an impact due to the collision of the tab portion 8a of the actuator 7, in order to reduce the impact received by the ramp portion 14, the side of the head holding plane 14e away from the recording medium 4 ( A third slope 14f that is inclined at a predetermined angle is formed on a surface adjacent to the unload side.

As shown in FIG. 6A, since the third inclined surface 14f is formed so as to be above the head holding plane 14e in the direction perpendicular to the surface of the recording medium 4, the tab portion 8a has the third inclined surface 14f. The distance h ₁ in the direction perpendicular to the surface of the recording medium 4 between the point m ₂ that collides with the head and the intersection m _{1 of} the second slope 14c and the first step side surface 14d is the intersection m ₁ with the head holding plane 14e. Is smaller than the distance h _{2 in the} direction perpendicular to the surface of the recording medium 4. On the other hand, as shown in FIG. 6B, the actuator 7 falls by a distance h corresponding to the drop height of the tab portion 8 a from the intersection point m ₁ in the recess 51, and the actuator 7 is the third slope on the upper surface 42 of the ramp portion 14. The collision speed v when colliding with 14f or the head holding plane 14e increases as the distance h corresponding to the drop height increases. In this case, as described above, it is influenced by the electromagnetic force generated with the spring force of the actuator 7 and the current supplied to the voice coil 10. Further, when a constant current is supplied to the voice coil 10 so as to retract the actuator 7 to the retracted position, the collision speed v ₁ at the head holding plane 14e when the tab portion 8a collides with the head holding plane 14e and stops. when, after impacting on the third inclined surface 14f, the comparatively showing collision speed v ₂ of the third inclined surface 14f in the case of stopping the head holding plane 14e, and a graph as shown in FIG. 6 (c) Become. Accordingly, when the magnetic disk device receives a power supply stop command or an emergency stop command and the rotation of the actuator 7 stops, the actuator 7 is guided by the ramp portion 14 and the tab portion 8a of the actuator 7 collides with the head holding plane 14e. When the collision energy is compared with the case where the collision is stopped after the collision with the third inclined surface 14f and the movement is lowered and stopped on the head holding plane 14e, the collision energy can be reduced in the latter case. . In other words, when the tab portion 8a collides with the third inclined surface 14f and then stops on the head holding plane 14e, the impact received by the third inclined surface 14f due to the collision of the tab portion 8a is greater when the tab portion 8a is subjected to the head. This is smaller than the impact received by the head holding plane 14e due to the collision of the tab portion 8a when the holding plane 14e directly collides and stops.

  In order to further reduce the impact received by the ramp portion 14, the actuator 7 collides with the crash stop 16 before the tab portion 8a collides with the third inclined surface 14f, and then the head passes through the third inclined surface 14f. You may comprise so that the holding | maintenance plane 14e may be reached. In the case of such a configuration, since the energy to rotate the actuator 7 is absorbed by the contact with the crash stop 16, it goes without saying that the impact received by the third inclined surface 14f is further reduced.

After the tab portion 8a of the actuator 7 collides with the third inclined surface 14f of the ramp portion 14, or after colliding with the third inclined surface 14f and colliding with the crash stop 16, the current supply to the voice coil 10 is stopped. Thereafter, the tab portion 8a slides down the third inclined surface 14f toward the head holding plane 14e by the urging force of the leaf spring portion 27, and stops at the head holding plane 14e which is the retracted position. In addition to this operation, the actuator 7 collides with the crash stop 16 before the tab portion 8a of the actuator 7 collides with the third inclined surface 14f, and then reaches the head holding plane 14e via the third inclined surface 14f. May stop. In any of the retracted positions, when the tab portion 8a of the head support arm 8 constituting the actuator 7 is in contact with the head holding plane 14e, the urging force F ₁ generated by the leaf spring portion 27 constituting the actuator 7 is used. Thus, the tab portion 8a presses the head holding plane 14e.

Briefly the angle theta ₂ of the third inclined surface 14f with respect to the head holding plane 14e. Since α ₂ described above is an angle formed by the third inclined surface 14 f on the unloading side from a surface perpendicular to the head holding plane 14 e, there is a relationship of θ ₂ = 90 ° + α ₂ . Therefore, when the current supply to the voice coil 10 is stopped, in order for the tab portion 8a of the actuator 7 to slide down the third slope 14f,
180 ° −θ ₂ = (90 ° −α ₂ ) ° ≧ tan ⁻¹ μ ₂
And,
θ ₂ ≧ 90 °
If it is.

Therefore,
90 ° ≦ θ ₂ ≦ (180 ° −tan ⁻¹ μ ₂ )
Is required.

However, μ ₂ = the coefficient of friction between the tab portion 8a of the actuator 7 and the third slope 14f.

Here, as an example, if μ ₂ = 0.2,
tan ^-1 μ ₂ ≒ 11 °
Therefore, the third inclined surface 14f is 90 ° ≦ θ ₂ ≦ 169 ° with respect to the head holding plane 14e.
By forming so as to have the angle theta _2, it is possible to tab portion 8a of the actuator 7 is slid down until the head holding plane 14e is retracted positions third slope 14f of the lamp unit 14.

  In the above description, the ramp block 15 having the ramp portion 14 for guiding the actuator 7 to the retracted position is provided in the vicinity of the outer peripheral portion of the recording medium 4. However, the present invention is not limited to this and is well known. As described above, when the spindle motor that rotates the recording medium 4 is a fixed shaft type, another lamp portion is attached to the fixed shaft of the spindle motor, or another lamp portion is attached to a structural member such as a housing or a cover of the apparatus. It goes without saying that a ramp block may be provided in the vicinity of the rotation center 1 of the recording medium 4 depending on the mounting structure. In this case, the first inclined surface 14a, the first flat surface 14b, the second inclined surface 14c, and the first step side surface 14d of the ramp portion 14 are on the recording area side (load) of the recording medium 4 with respect to the head holding flat surface 14e. The third inclined surface 14f is provided on the rotation center 1 side of the recording medium 4 with respect to the head holding plane 14e (that is, on the opposite side of the recordable area in this case, that is, on the unload side). It is necessary to provide a configuration in which the magnet is disposed on the recording medium 4 side with respect to the actuator 7 provided with the voice coil 10 so as to face the voice coil 10.

The shape of the tab portion 8a of the head support arm 8 that slides on the upper surface 42 of the ramp portion 14 configured in this manner will be described. In order to slide the first inclined surface 14a, the first flat surface 14b, the second inclined surface 14c, and the first step side surface 14d of the ramp portion 14, the outer peripheral shape of the tab portion 8a is an edge at an outer periphery of at least a half or more. It is necessary that there is no catching part such as a partial circle or a cylindrical shape in which at least half of the circumference is cylindrical. Further, the shape is not limited to a cylindrical shape, and may be an elliptical shape or other shapes as long as the shape has a smoothly changing curved surface. The head support arm 8 having the tab portion 8a is usually formed of a plate-like material. As shown in FIG. 7A, the outer periphery of the head support arm 8 is formed by a well-known processing method such as press processing. The tab portion 8a may be formed by processing so as to have a partial moon shape in which at least half of the circumference is cylindrical. Also, as shown in FIGS. 7B and 7C, the plate-like tab portion 8a is integrally molded with a material such as a resin so that the outer shape has a shape such as a partial moon shape or a cylindrical shape. Also good. However, in the case where the outer periphery of the tab portion 8 is processed by a known processing method such as press processing so as to have a partial moon shape, an angle range exceeding 180 ° as shown in FIG. In order to perform the bending process so as to form a circular shape, a very complicated process is required. Usually, as shown in FIG. 7 (d), the angle is 180 ° or slightly smaller than 180 °. It becomes a shape that is bent so as to have a partial circular shape. Incidentally, when the upper surface 42 of the lamp unit 14 is the tab portion 8a slides, edges e ₁ and e ₂ shown in FIG. 7 (d) is in contact with the upper surface 42 of the lamp unit 14 prevents a smooth sliding it so as not, as shown in FIG. 7 (e), to have a peripheral portion smooth surface in the vicinity of the edge portion e ₁ and e _2, the polishing or laser processing or the like, the machining of the edge process It is desirable to apply.

  Next, a description will be given of a case where the magnetic disk device is subjected to a very large external impact such as vibration during carrying or dropping, or an impact caused by a collision with another object when the magnetic disk device is stopped.

The actuator 7 that rotates around the rotation shaft 5 receives linear acceleration and angular acceleration due to a large external impact applied to the magnetic disk device. The impact force due to the linear acceleration acts on the center of gravity of the actuator 7, and the magnitude of the impact force depends on the weight of the actuator 7. Further, the impact force due to the angular acceleration acts as a couple at the center of the rotating shaft 5, and the magnitude of the couple generated by the impact force depends on the moment of inertia of the actuator 7. On the other hand, as described above, the center of gravity of the actuator 7 is set so as to substantially coincide with the axis of the rotating shaft 5 around which the actuator 7 rotates. The actuator 7 operates around the axis, and the actuator 7 is rotated around this line with a line connecting the contact points P ₁ and P ₂ of the rotating shaft 5 and the two pivots 29a and 29b as fulcrums (support axes). The force to be moved hardly works, and the actuator 7 hardly turns. However, the actuator subunit 26, the spring fixing member 28, the leaf spring portion 27, and the collar 32 have a force in the axial direction of the rotating shaft 5 due to a component force in the axial direction of the rotating shaft 5 due to an impact force due to linear acceleration. In response, the actuator subunit 26 exerts a force to move in the axial direction of the rotary shaft 5 against the stress of the leaf spring portion 27. Therefore, even if the force to move in the axial center direction of the rotating shaft 5 works and the actuator subunit 26 moves, the tab portion 8a of the head support arm 8 is lifted from the head holding plane 14e of the ramp portion 14. When the movement is completed and restored, the original position before the movement, that is, the head holding plane 14e of the ramp portion 14 is returned.

Further, the couple generated by the impact force due to the angular acceleration works to rotate the actuator 7 around the rotation shaft 5, and pushes the tab portion 8 a of the head support arm 8 against the head holding plane 14 e of the ramp portion 14. The actuator 7 is moved against the friction caused by the pressure (the biasing force F ₁ described above). Therefore, the head slider 9 mounted on the actuator 7 is moved from the retracted position of the actuator 7 toward the recording medium 4 or in the opposite direction due to a large external shock when the magnetic disk device is stopped. The force is generated by the impact force due to the angular acceleration in the impact.

Therefore, when the actuator 7 receives a large external impact to rotate the recording medium 4, the surface perpendicular to the head holding plane 14 e of the lamp unit 14, that is, a plane substantially parallel to the rotation shaft 5. In order to prevent the tab portion 8a of the head support arm 8 from moving in the direction of the recording medium 4 on the first step side surface 14d formed so as to have an angle of α ₁ ° with respect to the loading side, FIG. As shown in FIG. 5, the impact force of the angular acceleration due to the impact received by the tab portion 8a in the acting force acting on the first step side surface 14d at the contact S where the tab portion 8a contacts the first step side surface 14d of the ramp portion 14 is shown. component force Fsinarufa ₁ of the first step side surface 14d direction of F is the force component Fcosarufa ₁ up for the direction perpendicular to the first step side surface 14d of the impact force F of the angular acceleration by impact the tab portion 8a receives Friction force by the component force _{F 1} sin .alpha ₁ in the direction perpendicular to the first step side surface 14d of the urging force _{F 1} of the tab portion 8a for fine head holding plane _{14e μ 1 (Fcosα 1 + F} 1 sinα 1) ( where, mu ₁ the the friction coefficient) between the first step side surface 14d and the tab portion 8a, a first force component _{F 1} cos [alpha] ₁ of the step side 14d direction of the urging force _{F 1} of the tab portion 8a with respect to the head holding plane 14e It must be smaller than the sum. That is, the following (Formula 1) may be satisfied.

_{Fsinα 1 ≦ μ 1 (Fcosα 1} + F 1 sinα 1) + F 1 cosα 1 ··· ( Equation 1)
On the other hand, since μ ₁ > 0, F ₁ > 0, sin α ₁ ≧ 0, and cos α ₁ ≧ 0, there is a relationship of (Expression 2).

μ ₁ F ₁ sinα ₁ + F ₁ cosα ₁ > 0 (Expression 2)
Therefore, the following relationship (Equation 3) is obtained.

_{μ 1 Fcosα 1 <μ 1 (} Fcosα 1 + F 1 sinα 1) + F 1 cosα 1 ··· ( Equation 3)
Therefore, if at least the following (Equation 4) is satisfied, the tab portion 8a does not move in the direction of the recording medium 4.

Fsinα ₁ ≦ μ ₁ Fcosα ₁ (Formula 4)
Therefore, the first step side surface 14d is formed so as to satisfy the following (Formula 5) with respect to a plane perpendicular to the head holding plane 14e.

α ₁ ≦ tan ⁻¹ μ ₁ (Formula 5)
Therefore, if θ ₁ = (90 ° + α ₁ ), θ ₁ satisfies the following (formula 6) with respect to the head holding plane 14e.

90 ≦ θ ₁ = (90 ° + α ₁ ) ≦ 90 ° + tan ⁻¹ μ ₁ (Expression 6)
As an example, if μ ₁ ≧ 0.2, α ₁ ≦ 11 °, and the first step side surface 14d of the ramp portion 14 is θ ₁ = 90 ° to 101 ° with respect to the head holding plane 14e.
By forming so as to have the angle theta _1, tab portion 8a of the head support arm 8 constituting the actuator 7 it is prevented from moving by the first step side surface 14d of the lamp unit 14 in the direction of the recording medium 4 Will be.

When the actuator 7 receives an impact in a direction away from the recording medium 4, the third inclined surface 14f of the ramp portion 14 has an angle of α ₂ ° on the unloading side with respect to a plane perpendicular to the head holding plane 14e. The tab portion 8a, which is formed as described above, receives the impact force of the angular acceleration due to the impact, abuts against the third inclined surface 14f, relieves the impact force, and at the same time, the tab portion 8a contacts with the third inclined surface 14f. Even if 8a slides the actuator 7 on the third inclined surface 14f in a direction away from the recording medium 4, the voice coil holder that constitutes the actuator 7 on the crash stop 16 provided on the chassis or the housing or other structural member 23 is abutted and the actuator 7 is prevented from rotating away from the recording medium 4, and is separated from the head holding plane 14e which is the retracted position. Do not be. However, when the actuator 7 receives an impact in a direction away from the recording medium 4 and the tab portion 8a tries to slide on the third slope 14f in a direction away from the recording medium 4, θ ₂ = Since there is a relationship of 90 + α ₂ , when the angle θ ₂ is considered, the sectional shape of the tab portion 8a of the head support arm 8 constituting the actuator 7 is slightly larger than 180 ° or 180 ° as shown in FIG. In the case of a bent shape that becomes a partial circular shape within a small angle range, the angle of the third inclined surface 14f with respect to the head holding plane 14e is formed so as to have an angle of approximately 90 °. , the edge portion of the tab portion 8a _{e 1} (Fig. 7 (d) refer) occurs a possibility that is caught by the third inclined surface 14f, so that damage to the actuator 7 or ramp block 15 It may occur. Therefore, the angle θ ₂ of the third inclined surface 14f with respect to the head holding plane 14e described above is
θ ₂ = 95 ° to 165 °
Further, as shown in FIG. 9, at the intersection of the head holding plane 14e and the third inclined surface 14f, the radius of curvature r ₀ of the outer shape of the partial moon shape of the tab portion 8a is set. (FIG. 7 (d) refer) and substantially equal to, or may have a shape such as to connect the head holding plane 14e and the third inclined surface 14f so as to have a large radius of curvature r _1. Thus, by making the shape connected with curvature, the contact surface between the tab portion 8a and the upper surface 42 of the ramp portion 14 is enlarged, and the contact stress due to the pressing of the tab portion 8a is reduced. Wear of the portion 14 can be reduced. Whether the width b ₁ of the head holding plane 14e in the direction perpendicular to the rotation center of the rotation shaft 5 of the actuator 7 is substantially the same as the width b ₀ of the tab portion 8a in the same direction (see FIG. 7D). Alternatively, it is desirable to have a width larger than that.

  Next, the movement of the actuator 7 in the direction of the recording medium 4 from the head holding plane 14e, which is the retracted position, in the loading operation at the start of the operation when the operation command is instructed to the magnetic disk device will be described.

  When a current is supplied to the voice coil 10, the actuator 7 is rotated by the VCM 19, and a magnetic force according to Fleming's right-hand rule acts between the voice coil 10 and the magnet 11. The rotation direction of the actuator 7 and the repulsion (attraction) direction toward the magnet 11 are determined by the direction and the polarity of the magnet 11 facing the voice coil 10. An example of the rotational torque applied to the actuator 7 generated by the VCM 19 when a constant current is supplied to the voice coil 10 and the repulsive driving torque in the direction opposite to the magnet 11 direction are shown in FIGS. ). However, FIG. 10B shows the repulsion driving torque when the VCM 19 is instructed to load. FIG. 10 shows the position of the VCM 19 in the actuator 7 when the magnetic head (not shown) is located at the center position 18 of the recordable area Ra of the recording medium 4 shown in FIG. The rotation angle of the VCM 19 with the retracted position direction of the actuator 7 from the position to the + side is the horizontal axis.

When an operation command is instructed to the magnetic disk device, a current is supplied to the voice coil 10, and the actuator 7 is moved in the direction of the recording medium 4 (load side) by the rotational torque of the VCM 19 as shown in FIG. Turn to. At the same time, as shown in FIG. 10B, the actuator 7 is given a repulsive driving torque of the VCM 19 to move the tab portion 8a of the head support arm 8 upward from the head holding plane 14e of the ramp portion 14. And At this time, the rotational torque of the VCM 19 generates a force for moving the actuator 7 toward the recording medium 4 (to the load side), and is driven horizontally in the tab portion 8 a of the head support arm 8 constituting the actuator 7. force _{F 3} acts so as to press the first step side surface 14d of the lamp unit 14. Further, in a direction perpendicular to the repulsive driving torque surface of the actuator 7 recording medium 4 of VCM 19, becomes a torque to be rotated around the line connecting the contact point P ₁ and the contact point P ₂ of the pivot 29a and the pivot 29b , the vertical driving force F ₄ to attempt to lift the tab portion 8a upward acts on the tab portion 8a.

The relation of the acting force that the tab portion 8a tries to press against the first step side surface 14d at the contact T that contacts the first step side surface 14d of the ramp portion 14 will be described with reference to FIG. The horizontal driving force _{F 3} by urging force _{F 1} and VCM19 acting on the tab portion 8a becomes a pressing force to the first step side surface 14d, on the other hand, the vertical driving force _{F 4} by VCM19 the tab portion 8a from the first step side surface 14d It becomes the separation force that tries to separate. Therefore, separating component in the direction perpendicular to the first step side surface 14d of the separating force of the first first step pressing force component in the direction perpendicular to the side surface 14d f ₁ and the tab portion 8a of the pressing force of the step side 14d Depending on the relationship of the force f _2, a vertical driving force F ₄ is set that allows the actuator 7 to move over the first step side surface 14 d of the ramp portion 14 and rotate from the retracted position to the recording medium 4 side (to the load side). be able to.

Pressing component force f ₁ and separating component force f ₂ in the direction perpendicular to the first step side surface 14d, respectively become the following (Equation 7) and (8).

f ₁ = F ₁ sin α ₁ + F ₃ cos α ₁ (Expression 7)
f ₂ = F ₄ sin α ₁ (Expression 8)
Therefore, when the relationship between the pressing component force f ₁ and the separation component force f ₂ satisfies the following (Equation 9):
f ₁ ≦ f ₂ (Equation 9)
The pressing force against the first step side surface 14d of the tab portion 8a does not work. Thus, VCM 19 vertical driving force F ₄ according to rotate the first actuator 7 from the retracted position to overcome the step side 14d to the recording medium 4 side of the lamp unit 14 satisfies the following equation (10) It should be set as follows.

F ₄ ≧ F ₁ (Equation 10)
In addition, when the relationship between the pressing component force f ₁ and the separation component force f ₂ is (Equation 11) shown below,
f ₁ > f ₂ (Formula 11)
The first actuators 7 to rotate the recording medium 4 side beyond the step side surface 14d, the frictional force f ₃ to the first stepped side surface 14d by the pressing force component f ₁ and separating component force f ₂ and tab portion 8a than the first step side surface 14d direction anti resultant force _{f 5} where the component force _{f 4} is applied to the biasing force _{F 1} of the first direction of the step side 14d direction of the component force _{f 6} in the vertical driving force _{F 4} by VCM19 Should be made larger. That is, the frictional force _{f 3} and the component force _{f 4} is represented by the following respective (Equation 12) and (Equation 13).

f ₃ = μ ₁ (f ₁ −f ₂ ) = μ ₁ (F ₁ sin α ₁ + F ₃ cos α ₁ −F ₄ sin α ₁ ) (Equation 12)
f ₄ = F ₁ cos α ₁ (Expression 13)
Thus, anti resultant force _{f 5} is shown below as (Equation 14).

f ₅ = f ₃ + f ₄ = F ₁ cos α ₁ + μ ₁ (F ₁ sin α ₁ + F ₃ cos α ₁ -F ₄ sin α ₁ ) (Formula 14)
On the other hand, the component force _{f 6} of the first step side surface 14d direction of the vertical driving force _{F 4} is represented by the following equation (15).

f ₆ = F ₄ cos α ₁ (Expression 15)
Therefore, in order to rotate the first actuator 7 from the retracted position to overcome the step side 14d to the recording medium 4 side of the lamp unit 14 min first step side surface 14d direction of the vertical driving force F ₄ by VCM19 between the force f ₆ and anti resultant force f _5, the following it is sufficient to satisfy (equation 16).

F ₄ cosα ₁ > F ₁ cosα ₁ + μ ₁ (F ₁ sinα ₁ + F ₃ cosα ₁ −F ₄ sinα ₁ ) (Expression 16)
Therefore, the following (Expression 17) is obtained.

F ₄ > F ₁ + μ ₁ (F ₁ tan α ₁ + F ₃ −F ₄ tan α ₁ ) (Expression 17)
Here, F ₄ > 0
tanα ≧ 0
Therefore, the following (formula 18) is obtained.

F ₁ + μ ₁ (F ₁ tan α ₁ + F ₃ )> F ₁ + μ ₁ (F ₁ tan α ₁ + F ₃ −F ₄ tan α ₁ ) (Equation 18)
Therefore, the vertical driving force F ₄ by the VCM 19 is expressed by the following (Equation 19).

F ₄ > F ₁ + μ ₁ (F ₁ tan α ₁ + F ₃ ) (Equation 19)
Therefore, if the vertical driving force F ₄ by the VCM 19 is set so as to satisfy the above (Equation 19), the actuator 7 is moved from the retracted position to the recording medium 4 side over the first step side surface 14 d of the ramp portion 14. Can be moved.

  Therefore, when the operation of the disk device is started, a repulsive driving torque is generated between the voice coil 10 and the magnet 11 constituting the VCM 19, and the head support arm 8 passes through the axis of the rotating shaft 5 of the actuator 7, and The torque that tries to rotate around a line perpendicular to the center line 8d in the longitudinal direction of the head support arm 8 acts, and a force that moves the tab portion 8a at the tip of the head support arm 8 upward is generated. At the same time, a force for rotating the actuator 7 around the rotation axis is also generated, so that the actuator 7 can be detached from the retracted position and easily moved in the direction on the surface of the recording medium 4.

In the loading operation at the start of the operation, the tab portion 8a is in contact with the first step side surface 14d even when the actuator 7 moves from the head holding plane 14e, which is the retracted position, to the recording medium 4 direction (load side). It tries to slide to the recording medium 4 side along the step side surface 14d. At this time, the cross-sectional shape of the tab portion 8a of the head support arm 8 constituting the actuator 7 becomes a partial circular shape within a range of 180 ° or slightly smaller than 180 ° as shown in FIG. In the case of such a bent shape, if the angle of the first step side surface 14d with respect to the head holding plane 14e is formed to be an angle of about 90 °, the actuator 7 described above can be used as the recording medium 4. As in the case of the third inclined surface 14f when receiving an impact in a direction away from the edge, the edge portion e ₂ (see FIG. 7D) of the tab portion 8a is caught by the first step side surface 14d, and the actuator 7 Or the lamp block 15 may be damaged. Therefore, the angle θ ₁ of the first step side surface 14d with respect to the head holding plane 14e described above is
θ ₂ = 95 ° to 100 °
Further, as shown in FIG. 9, the radius of curvature r ₀ of the partial moon-like shape of the tab portion 8a at the intersection of the head holding plane 14e and the first step side surface 14d as shown in FIG. Figure 7 (d) see) and may be substantially a shape like connecting the head holding plane 14e and the first step side surface 14d so as to be formed curved to have a radius of curvature r ₂ of the same size .

  As shown in FIG. 10B, the repulsion driving torque when the actuator 7 is in the vicinity of the retracted position is large, but the repulsion driving torque when moving over the recording area of the recording medium 4 is very high. It becomes smaller and does not adversely affect the recording / reproducing operation of the magnetic disk device.

  By configuring the magnetic disk device with the actuator 7, the VCM 19 and the ramp block 15 as described above, the head slider 9 constituting the actuator 7 even when a large external shock is applied when the magnetic disk device is stopped (not operating). The tab portion 8a of the head support arm 8 in which is disposed does not separate from the head holding plane 14e of the ramp portion 14 which is the retracted position. Further, when the magnetic disk device is operated, the tab portion 8a is configured by providing the magnet 11 on the opposite side of the recording medium to the actuator 7 provided with the voice coil 10 of the VCM 19 so as to face the voice coil 10. Is easily detached from the head holding plane 14e of the ramp portion 14, and the actuator 7 is rotated so that the head slider 9 faces the surface of the recording medium 4, so that the magnetic disk device can be operated for recording and reproduction. In addition, when an emergency stop command is input to the magnetic disk device, the tab portion 8a of the head support arm 8 provided in the actuator 7 has a first step side surface 14d constituting the upper surface 42 of the ramp portion 14 of the ramp block 15, and the head. It enters the recess 51 formed by the holding plane 14e and the third inclined plane 14f, and passes through the third inclined plane 14f that constitutes the upper surface 42 of the ramp portion 14 that forms the recess 51, to the head holding plane 14e that is the retracted position. Therefore, since the tab portion 8a, that is, the actuator 7 is held in the retracted position, the tab portion 8a collides with the third inclined surface 14f of the ramp portion 14 in which the concave portion 51 is formed, so that the energy of the collision is reduced. Damage to the tab portion 8a of the actuator 7 or the ramp portion 14 of the ramp block 15 due to a collision. It is possible to suppress. Therefore, it is not necessary to use a separate holding member separately from the ramp block for holding the head of the actuator when the magnetic disk device is stopped, reducing the cost of the head holding member, and requiring a large space for holding. It is possible to realize a head holding member that does not. In addition, by using such a head holding member, it is possible to realize a magnetic disk device that is reduced in size without requiring a large space for holding.

  In the above description, the retracted position of the actuator 7 is outside the recording medium 4, and the arrangement position of the magnet 11 at that time is the opposite side of the recording medium 4 side with respect to the actuator 7 provided with the voice coil 10. However, as shown in FIGS. 12 and 13, the lamp block is located inside the recording area of the recording medium 4, that is, near the rotation center 1 of the recording medium 4. 15 is provided on the recording medium 4 side with respect to the actuator 7 on which the voice coil 10 is provided, and another voice coil 104 is provided so as to face the other magnet 105. It is also possible to configure another VCM. Such a configuration will be briefly described below. 12 and 13, the same elements as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  In FIG. 12, the actuator subunit 26 provided in the actuator 7 is pivotally supported around a rotation shaft 5 having a bearing, and by driving a VCM 119 which is a rotation drive means, It can be positioned at a predetermined track position. The actuator 7 is composed of the actuator subunit 26, the bearing portion, and the VCM 119. As the rotation driving means, a VCM 119 as shown in FIG. 12 can be used, but it is responsible for the rotation of the head support arm 8 in a direction horizontal to the surface of the recording medium 4.

  The recording medium 4 can be rotated around the rotation shaft 102 at a predetermined number of rotations by a rotation driving means. For example, a spindle motor can be used as the rotation driving means. The housing 101 holds these in a predetermined positional relationship and is sealed with a lid (not shown) to prevent the recording medium 4 and the head from being deteriorated by external corrosive gas or dust. These structures are the same as those of the magnetic disk apparatus shown in FIG.

  Next, the configuration of the actuator subunit 26 and the actuator 7 included in the magnetic disk device shown in FIG. 12 will be described with reference to FIG.

  In FIG. 13, a plate spring portion 127 made of an elastic member, a head support arm 108, and an arm plate 107 are formed by processing a single plate material. The leaf springs 127 are provided on both sides of the head support arm 108, and these are connected to the extension 107 a of the arm plate 107 at the ends. The leaf spring 127 is also connected to the end 109 side of the head support arm 108. The leaf spring 127 and the extension 107a of the arm plate 107 are fixed to the base arm 106 by, for example, laser welding at positions indicated by Q and S, respectively. Although not shown in FIG. 13, a voice coil portion having a voice coil fixed to a voice coil holder having a hole through which the rotation shaft 5 is passed on the opposite side to the head slider 9 is provided. Together with a magnet (not shown) or the like, a VCM 119 which is a rotation driving means shown in FIG. 12 is configured. The magnetic disk apparatus shown in FIG. 12 does not have a pivot bearing portion in the portion of the rotating shaft 5, and a pivot bearing portion 129 is provided on the head slider 9 side from the rotating shaft 5 as shown below. It has been.

The base arm 106 is provided with a pivot bearing portion 129 including pivots 129a and 129b serving as a pair of joint portions, and the pivot bearing portion 129 constitutes a rotating bearing portion that is pivotally supported in the vertical direction of the recording medium. . The head support arm 108 abuts on a pivot bearing portion 129 that is a rotation bearing portion, is elastically held via a leaf spring portion 127, and can rotate only in a direction perpendicular to the surface of the recording medium 4. Note that the pair of pivots 129a and 129b that are the joints of the pivot bearing portion 129, which is a rotational bearing portion, abuts at _two contact points P ₁ and P ₂ of the head support arm 108 as shown in FIG. Yes. Accordingly, the elastic force of the leaf spring portion 127 biases one end of the head support arm 108 to which the head slider 9 is fixed toward the surface of the recording medium 4 (the direction of the center line 10a shown in FIG. 1). A compressive stress is generated at the contact points P ₁ and P ₂ . A line connecting the contact points P ₁ and P ₂ serves as a rotation axis in a direction perpendicular to the surface of the recording medium 4.

  Further, on the head support arm 108, another magnet 105 is fixed to an end portion 109 opposite to one end to which the head slider 9 is fixed, and on the opposite surface with respect to the rotation bearing portion. Another voice coil 104 is provided opposite to another magnet 105 to constitute another VCM. The rotation of the head slider 9 provided at one end of the head support arm in the direction perpendicular to the surface of the recording medium 4 is controlled by the other VCM. Note that the pivots 129a and 129b, which are joint portions of the pivot bearing portion 129, which is a pivot bearing portion, are perpendicular to the longitudinal center line (A-A line) of the head support arm 108 as shown in FIG. It is arrange | positioned in the position symmetrical with respect to this center line (AA line). Accordingly, the urging force to the head slider 9 during the operation of the magnetic disk device, that is, in the state where the head slider 9 floats with respect to the recording medium 4, is a head support arm by the pivots 129 a and 129 b of the pivot bearing portion 129. The biasing force generated by the elasticity of the leaf spring 127 is controlled so as to be balanced with the driving force of the VCM configured by providing another voice coil 104 facing the other magnet 105. .

  Note that the retracted position 103 (corresponding to the ramp block 15 shown in FIGS. 1 and 4) of the actuator 7 provided inside the recording area of the recording medium 4 shown in FIG. 12, that is, in the vicinity of the rotation center 1 of the recording medium 4. Since the structure, configuration, etc. are essentially similar to the contents described with reference to FIGS.

In the above-described embodiment of the present invention, as shown in FIGS. 2 and 3, the first rotation shaft that is the rotation shaft of the bearing portion 31 that becomes the first bearing, and the second bearing. Although the description has been made with the configuration in which the lines passing through the contact points P ₁ and P ₂ that are the second rotation shafts of the joint portion of the pivot bearing portion 29 to be orthogonal to each other, the embodiment of the present invention is limited to this configuration. Is not to be done. For example, a base arm whose one end is fixed to a bearing portion 31 serving as a first bearing is provided, and a joint portion of a pivot bearing portion 29 serving as a second bearing is disposed on the other end side of the base arm, and the base arm is provided. If the other end of the head and the head support arm 8 are fixed by the leaf spring portion 27, a configuration in which the second rotating shaft is provided at a position away from the first rotating shaft becomes possible. In this case, unlike the configuration in which the first rotation axis and the second rotation axis are orthogonal to each other as described with reference to FIGS. 2 and 3, the surface having the first rotation axis and the second rotation axis The plane which has an axis becomes the composition which intersects perpendicularly. FIG. 14 is an example of such a configuration. FIG. 14A is a side view showing another configuration of the actuator provided in the magnetic disk device according to the embodiment of the present invention, and FIG. It is a fragmentary perspective view of the actuator shown to 14 (a). 14, the same elements as those in FIGS. 2 and 3 are denoted by the same reference numerals.

  Hereinafter, an example of a configuration in which the first rotation axis and the second rotation axis illustrated in FIG. 14 are not directly orthogonal will be briefly described. In FIG. 14, a dimple 8 c is provided on the lower surface of the head support arm 8 on the head support arm 8 having a tab portion 8 a at one end so as to contact the vicinity of the center portion of the head slider 9, and the gimbal mechanism 21 is interposed. A head support arm unit 22 is configured by arranging a head slider 9 on which a magnetic head (not shown) is mounted. Since the gimbal mechanism 21 has already been described in the configuration shown in FIGS. 2 and 3, it is omitted to avoid duplication.

On the other hand, one end of a leaf spring portion 27, which is an elastic means bent in two steps in a substantially Z-shaped cross section, is the upper surface on the other end side of the head support arm 8, and the first base arm 201 constituting the pivot bearing. The head support arm 8 and the first base arm 201 constituting the pivot bearing are elastically connected to each other. A pair of pivots 29a and 29b serving as joint portions are formed on the lower surface in the vicinity of the leaf spring portion 27 of the first base arm 201 constituting the pivot bearing. A pair of pivot 29a, 29b constitute the joint portion of the pivot bearing part, an upper surface and each contact point _P 1 of the head supporting arm 8, _{P 2} abuts with the head supporting arm 8 to the contact point _P 1, _{P 2} as a fulcrum The leaf spring portion 27 acts so as to push down the tab portion 8a side. The first base arm 201 constituting the pivot bearing is integrated with a second base arm 202 formed on the side opposite to the joint portion of the leaf spring portion 27, for example, from a hollow cylindrical projection or the like. It is fixedly connected to the connecting portion 203. Further, the contact points P ₁ , P _{1 of} the pair of pivots 29 a, 29 b that are the joints of the pivot bearings where the center of gravity of the head support arm unit 22 provided with the head slider 9 contacts the upper surface of the head support arm 8. _The balancer 204 is fixed to one end of the head support arm 8 by setting the mass (weight) of the balancer 204 so as to substantially match the midpoint of the line connecting the _two . Further, the voice coil holder 23 to which the voice coil 10 is attached is fixed to the other end of the second base arm 202 to constitute the voice coil unit 25.

  The above-described members, that is, the head support arm 8 constituting the head support arm unit 22 and the pair of pivots 29a and 29b serving as joint portions of the pivot bearing portion 29, are connected by the head support arm 8 and the leaf spring portion 27. First base arm 201 constituting the pivot bearing, a second base arm 202 coupled to the first base arm 201 constituting the pivot bearing, and a voice coil portion fixed to the second base arm 202 25 constitutes an actuator 226. Although the second base arm 202 and the voice coil unit 25 are described as separate members, they may be integrated into one unit.

The pressing force with which the slider 9 presses the surface of the recording medium 4 reaches the contact points P ₁ and P ₂ of each of the pair of pivots 29a and 29b serving as the joint portions. The height can be arbitrarily set according to the position of the connecting portion or the fixing portion of the head support arm 8 and the leaf spring portion 27. For example, a large urging force can be applied by forming the leaf spring portion 27 with a thick material with a high rigidity. Alternatively, even if the height of the apexes of the pair of pivots 29a and 29b serving as the joint portions is increased, a large urging force can be applied.

Next, the balancer 204 described above will be described. With reference to the second rotation axis connecting the respective contact points P ₁ and P ₂ of the pair of pivots 29a and 29b, which are joint portions provided on the first base arm 201 constituting the pivot bearing, the slider 9 The distance to the center of gravity is L ₁ , the distance to the center of gravity of the balancer 204 is L ₂ , the mass of the slider 9 is M ₁ , the mass of the balancer 204 is M ₂ , the mass of the rotating portion of the head support arm 8 and the gimbal mechanism When the total mass obtained by adding the masses of 21 is M ₃ , and the distance to the center of gravity at which the added total mass of the rotating portion of the head support arm 8 and the gimbal mechanism 21 is L ₃ is
L ₁ × M ₁ + L ₃ × M ₃ = L ₂ × M ₂ (Equation 20)
And so that may be set mass _{M 2} of the balancer 204.

As described above, when the gravity centers of the slider 9, the gimbal mechanism 21, the rotating portion of the head support arm 8 and the balancer 204 in the actuator unit 207 are set, the slider 9 collides with the recording medium 4 even when an impact force is applied. Can be prevented. For example, it is assumed that an impact force is applied in the direction indicated by Q in FIG. An impact force F ₅ proportional to the mass M ₁ acts on the slider 9. An impact force F ₆ proportional to the mass M ₂ acts on the balancer 204. Further, an impact force F ₇ proportional to the total mass M ₃ acts on the rotating portion of the head support arm 8 and the gimbal mechanism 21.

Since the actuator unit 207 is set so as to satisfy (Equation 20), L ₁ × F ₅ + L ₃ × F ₇ = L ₂ × F ₆ (Equation 21) with respect to these impact forces. )
The relationship holds. As a result, even when an impact is applied from the outside, the actuator unit 207 has the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b which are the joint portions of the first base arm 201 constituting the pivot bearing. No force is generated to rotate around the second rotation axis to be tied. Therefore, it is possible to prevent the slider 9 from colliding with the surface of the recording medium 4 and damaging the magnetic head (not shown) and the recording medium 4 mounted on the slider 9. That is, the center of gravity P of the actuator unit 207 on the line connecting the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b of the first base arm 201 constituting the head support arm and the pivot bearing (see FIG. If it is designed to be substantially the same position as that (not shown), it is possible to realize the actuator 226 constituting the stable actuator unit 207 with less vibration against external impacts and the like. The actuator unit 207 having the greatest impact resistance can be realized when the position of the center of gravity of the actuator unit 207 coincides with the above-described midpoint P. However, the joint of the first base arm 201 constituting the pivot bearing portion can be realized. As long as it is on a line connecting the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b, the actuator unit 207 having practically sufficient impact resistance even if it is displaced from the middle point P can be realized. it can.

Further, if the force acting between the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b of the first base arm 201 constituting the actuator unit 207 and the pivot bearing portion is F ₈ ,
F ₅ + F ₆ + F ₇ > F ₈ (Formula 22)
If so, the two pivots 29a and 29b, which are joint portions of the first base arm 201 constituting the pivot bearing portion, and the actuator unit 207 are separated from each other. But,
F ₅ + F ₆ + F ₇ ≦ F ₄ (Equation 23)
If so, the two pivots 29a and 29b that become the joint portion of the first base arm 201 constituting the pivot bearing portion and the actuator unit 207 are not separated from each other. The vertical driving force F ₄ that satisfies such a condition is caused by an internal stress generated from the rotational moment generated by the leaf spring portion 27 of the head support arm 8, and this force can be arbitrarily set as described above. Therefore, it is easy to prevent the two pivots 29a and 29b, which are joint portions of the first base arm 201 constituting the pivot bearing portion, from being separated from the actuator unit 207 even when receiving an impact force.

Further, the two pivots 29a serving as the joint portion of the first base arm 201 constituting the pivot bearing portion with respect to the impact force in the direction indicated by R in FIG. 14, that is, in the direction parallel to the surface of the recording medium 4. 29b, the center of gravity of the actuator unit 207 coincides with the second rotation axis connecting the contact points P ₁ and P ₂ of the actuator 29b, so that no rotational moment is generated in the actuator unit 207. 4 can be prevented from colliding.

Therefore, during the operation of the magnetic disk device, the load load of the head slider 9 when the head slider 9 attached to the head support arm unit 22 via the gimbal mechanism 21 is floating with respect to the surface of the recording medium 4 is: Compressive stress in the direction of the recording medium 4 as a reaction force due to deformation of the leaf spring portion 27 with respect to the head support arm unit 22 due to the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b serving as joint portions of the pivot bearing portion The head slider 9 is lifted by the relationship between the urging force in the direction of the recording medium 4 applied to the head slider 9 and the levitation force in the opposite direction, and the leaf spring portion 27 is deformed, so that the recording with the head slider 9 is performed. The recording / reproducing of the magnetic disk device is performed while maintaining a certain gap between the medium 4 and the configuration shown in FIGS. It does not change.

Next, the position of the pair of pivots 29a and 29b provided so as to be the joint portion of the first base arm 201 constituting the pivot bearing portion will be described once again. The lines connecting the contact points P ₁ and P ₂ at which the pivot 29 a and the pivot 29 b serving as the joint portions contact the upper surface of the head support arm 8 are perpendicular to the longitudinal center line 8 d of the head support arm 8. The center line 8d in the longitudinal direction of the head support arm 8 is formed so as to be perpendicular to the axis of the first rotation shaft of the bearing portion 31. With this configuration, the actuator unit 207 rotates in a direction perpendicular to the surface of the recording medium 4 around a line connecting the contact points P ₁ and P ₂ of the pair of pivots 29a and 29b serving as a joint. The head support arm 8 constituting the actuator unit 207 rotates counterclockwise by the elastic force of the leaf spring 27, and the head slider 9 mounted on the head support arm 8 is biased toward the recording medium 4. Will be. Incidentally, the line connecting the contact point P ₁ and the contact point P _2, a first line perpendicular to the plane formed by the longitudinal center line 8d of the axis and the head support arm 8 of the pivot axis of the bearing portion 31 if well, it is desirable to arrange so that the symmetrical positions from each other with respect to the center line 8d and the contact point P ₁ and the contact point P _2.

  The actuator 226 described with reference to FIG. 14 receives an emergency stop command due to an external factor such as a ramp for guiding the actuator 226 in the unloading operation and guiding the tab portion 8a to the retracted position, and an impact. In this case, the crash stop that causes the voice coil holder 23 of the voice coil unit 25 to collide with the actuator 226 to prevent excessive rotation of the actuator 226 is not shown. Even in the actuator 226 in which the first bearing and the second bearing are separated, the ramp portion and the crash stop shown in FIGS. 1 and 4 to 7 can be applied as they are. Therefore, here, in order to avoid duplication, description of the configuration and operation of the ramp unit and crash stop is omitted.

  Further, in the actuator 226 shown in FIG. 14, the base arm is divided into the first base arm 201 and the second base arm 202 constituting the pivot bearing and fixedly coupled by the coupling portion 203. In addition to such a configuration example, for example, the first base arm 201 constituting the pivot bearing is configured by fitting the hole portion of the coupling portion 203 of the first base arm 201 constituting the pivot bearing to the bearing portion 31. A configuration in which the second base arm 202 is an integrated base arm is also possible.

In the example shown in FIG. 14 described above, the pair of pivots 29a and 29b, which are the joint portions of the first base arm 201 constituting the pivot bearing, are brought into contact with the upper surface of the head support arm at the respective contact points P ₁ and P ₁ . _As shown in FIG. 15, a pair of pivots 29a and 29b serving as joints are formed on the head support arm, and the lower surface of the base arm and the respective contact points P ₁ , it may be configured to abut at P _2. FIG. 15A is a partial side view showing another configuration of the actuator provided in the magnetic disk apparatus according to the embodiment of the present invention, which is an example of the configuration in which the pivot is formed toward the head support arm. FIG. 16B is an exploded perspective view of the actuator shown in FIG. In FIG. 15, the same elements as those in FIG.

In FIG. 15A, the second base arm, the bearing portion, and the voice coil portion are omitted, and a pair of pivots 29a serving as joint portions constituting the pivot bearing serving as the second bearing, 29b is formed on the other end side of the head support arm 8 having the tab portion 8a at one end, and the lower surfaces of the first base arm and a pair of joints 29a and 29b serve as contact points P ₁ , only contact with are configured in P ₂ is different from the actuator structure shown in FIG. 14 (a). Other configurations, operation methods, and the like are the same as those of the actuator shown in FIG.

  In the above description, the shape of the pivot is not mentioned, but the first base arm 201 or the head support arm 8 is brought into contact with the first base arm 201 or the head support arm 8 like a cone, a polygonal pyramid, a hemisphere, or a semi-ellipsoid. Any shape is acceptable. In addition to a semi-cylindrical or semi-elliptical cylinder having a so-called kamaboko shape, it is also possible to make contact with a line using a polyhedral ridge line. FIG. 15B shows an example of a pivot using a half cylinder.

  Further, in the embodiment of the present invention, the structure in which the pivot is formed toward the head support arm 8 is the first as shown in FIGS. 1, 2 and 3 in addition to the structure shown in FIG. Of course, it is also possible to adapt to a configuration in which the rotation shaft and the second rotation shaft are integrated to form an integrated rotation bearing.

Even in the configuration shown in FIG. 15, when an emergency stop command is input by an external factor such as a ramp for guiding the actuator in the unloading operation and guiding the tab portion 8 a to the retracted position, and an impact, Although a crash stop that collides a voice coil holder (not shown) of the voice coil unit for suppressing excessive rotation of the actuator is not shown, in the magnetic disk device according to the embodiment of the present invention, a pipette bearing is used. A pair of pivots 29a and 29b that form the joint portion to be formed is formed on the other end side of the head support arm 8 having the tab portion 8a at one end portion, and a pair that serves as a joint portion with the lower surface of the first base arm. pivot 29a, also an actuator having a configuration 29b is in contact with the contact point _P 1, _{P 2,} or 1, and FIG. 4 Lamp unit shown in FIG. 7, it will be appreciated that it is possible to crash stop is directly adapted.

  In the above description of the embodiment of the present invention, the magnetic disk device has been described as an example. However, the present invention is not limited to this, and a non-contact type disk recording / reproducing device such as a magneto-optical disk device or an optical disk device. It goes without saying that it may be applied to.

  As described above, according to the embodiment of the present invention, the degree of freedom in designing the actuator is drastically increased, the head support arm constituting the actuator is formed of a highly rigid material, and a large impact from the outside, etc. In addition to improving the impact resistance to the head slider, the load load on the head slider incorporated in the actuator can be increased, and it has high impact resistance against external vibration or impact during the operation of the disk device. The resonance frequency of the head support arm can be increased, the actuator can be rotated and positioned at a high speed, and an excellent actuator having a high access speed can be realized.

  In addition, when the magnetic disk device is operated so that the power is stopped or an emergency stop command is input and the tab portion of the head support arm is held in the retracted position, the tab portion is connected to the ramp portion. 3, the collision energy at this time can be suppressed to be small, and damage to the tab portion or the ramp portion can be suppressed. In addition, when the disk device is stopped (not operating), that is, when the actuator is held at the retracted position, the actuator is set at the center of gravity of the rotational axis of the linear acceleration against a large external impact. The actuator tries to move in response to a component force in the axial direction and a couple due to angular acceleration, but the first step side surface of the ramp portion or the crash stop moves the tab portion of the head support arm constituting the actuator. The head can be held on the head holding plane of the lamp unit, which is the retracted position of the actuator, and the head can be held in the retracted position with a simple configuration. Realization of a member becomes possible.

  Accordingly, the head support arm having the head slider and the tab portion is configured to rotate about a line that passes through the axis of the rotation shaft of the actuator and is perpendicular to the longitudinal center line of the head support arm. The first step side surface and the third inclined surface at a predetermined angle with respect to the head holding plane on both sides of the actuator and the head holding plane of the ramp portion that guides and holds the tab portion at the retracted position of the actuator By combining the ramp portion provided with the crush stop and the crash stop, it is possible to realize an actuator head holding method having very high impact resistance.

  A head support arm having a head slider and a tab portion in a direction perpendicular to the recording medium surface around a line perpendicular to the longitudinal center line of the head support arm and passing through the axis of the rotation shaft of the actuator An actuator configured to rotate is disposed so as to be rotatable about a rotation axis, and is arranged at a predetermined angle on each side of the head holding plane of the lamp unit, which is a retracted position of the actuator. 1 step side surface and a third slope, and a ramp portion that guides the tab portion of the head support arm when the operation is stopped, and a crash stop for preventing the actuator from excessively swinging, a chassis, a housing, or other structural member And a magnet fixed to the upper yoke on the opposite side of the recording medium across the actuator on which the voice coil is disposed. By arranging the lower yoke on the medium side to configure the VCM and configuring the disk device to rotate the actuator by supplying current to the voice coil, the access speed can be increased and the operation Extremely high impact resistance during or during operation stop, reducing manufacturing costs without requiring multiple individual parts to hold the actuator in the retracted position, and large space for holding the head Therefore, it is possible to realize an excellent disk device that can be easily reduced in size.

  The head holding member according to the present invention uses a head holding member having a simple configuration to hold the actuator equipped with the signal conversion element in the retracted position, and has a low manufacturing cost and high impact resistance. It is a member and is useful for a magnetic recording / reproducing apparatus using a magnetic head, and a non-contact type disk recording / reproducing apparatus such as a magneto-optical disk apparatus, an optical disk apparatus, and the like.

1 is a plan view showing a schematic configuration of a main part of a magnetic disk device according to an embodiment of the present invention. 1 is a side view showing the configuration of an actuator provided in the magnetic disk device shown in FIG. 1 is an exploded perspective view showing the configuration of an actuator provided in the magnetic disk device shown in FIG. FIG. 1 is a plan view showing the vicinity of a ramp block when an actuator provided in the magnetic disk device shown in FIG. FIG. 4 is a cross-sectional view taken along the line BB showing the vicinity of the lamp portion and the recording medium in FIG. (A) is an enlarged partial sectional view for explaining the relationship between the tab portion and the ramp portion when the power supply of the magnetic disk apparatus according to the embodiment of the present invention is stopped or during an emergency stop operation. (B) is the drop height of the tab portion. A graph (c) showing the relationship between h and the collision speed v of the tab part to the ramp part shows the supply current to the voice coil, the collision speed v ₁ on the head holding plane, and the collision speed v ₂ on the third slope. (D) is an enlarged partial sectional view for explaining another relationship between the tab portion and the ramp portion when the magnetic disk device is powered off or during an emergency stop operation. (A)-(e) is sectional drawing which shows the shape of the various tab parts used for embodiment of this invention Explanatory drawing which shows the force in which a tab part presses the 1st level | step difference side surface of a lamp | ramp part when the impact which tries to rotate the actuator in embodiment of this invention to the recording medium side is received. The elements on larger scale which show the head holding plane vicinity of the lamp | ramp part in embodiment of this invention In the embodiment of the present invention, (a) is a graph showing the relationship between the position of the VCM when a constant current is supplied and the rotational torque of the actuator (b) is the repulsive drive acting on the VCM position and VCM during the load operation. Graph showing torque relationship Explanatory drawing which shows the action force of the tab part which presses the 1st level | step difference side surface in embodiment of this invention The perspective view which shows schematic structure of the principal part of another magnetic disc apparatus in embodiment of this invention. FIG. 12 is an exploded perspective view showing the configuration of an actuator provided in another magnetic disk device according to the embodiment of the present invention shown in FIG. FIG. 14A is a side view showing another configuration of the actuator included in the magnetic disk device according to the embodiment of the present invention. FIG. 14B is a partial perspective view of the actuator shown in FIG. FIG. 15A is a partial side view showing another configuration of the actuator provided in the magnetic disk device according to the embodiment of the present invention. FIG. 15B is an exploded perspective view of the actuator shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotation center 2,102 Rotating shaft 3 Rotor hub part 4 Recording medium 5 Rotating shaft 6 Bearing 7,226 Actuator 8,108 Head support arm 8a Tab part 8b, 23a, 29c Hole part 8c Dimple 8d, 10a Center line 9 (Head ) Slider 10 Voice coil 11 Magnet 12 Upper yoke 13 Lower yoke 14 Ramp part 14a First slope 14b First plane 14c Second slope 14d First step side face 14e Head holding plane 14f Third slope 14g Second Plane 15 Lamp block 16, 17 Crash stop 18 Center position 19,119 VCM
21 Gimbal mechanism 22 Head support arm unit 23 Voice coil holder 24, 204 Balancer 25 Voice coil part 26 Actuator subunit 27, 127 Leaf spring part 28 Spring fixing member 29, 129 Pivot bearing part 29a, 29b, 129a, 129b Pivot 30 Actuator Arm 31 Bearing portion 31a Flange 31b Thread portion 31c Cylindrical portion 32 Collar 32a Projection portion 32b, 42 Upper surface 33 Nut 41 Lamp mounting portion 51 Recess 101 Housing 103 Retraction position 104 Different voice coil 105 Different magnet 106 Base arm 107 Arm plate 107a extending portion 109 end 201 first base arm 202 and the second base arm 203 coupled portion 207 actuator unit b _{0, b 1} width e _{1, 2} the edge portion _{F, F 5, F 6,} F 7 impact force F ₁ biasing force F _{3, F 4} driving force _h, h _1, h ₂ height (distance)
L ₁ , L ₂ , L ₃ distance m ₁ intersection m ₂ collision point M ₁ , M ₂ , M ₃ mass P ₁ , P ₂ contact point Ra recordable area r ₀ , r ₁ , r ₂ radius of curvature S, T Contact points t ₁ , t ₂ , t ₂ ′, t ₃ , t ₃ ′, T ₁ , T ₂ Torque α ₁ , α ₂ , θ ₁ , θ ₂ angle μ ₁ , μ ₂ Friction coefficient

Claims (21)

When the actuator is unloaded in response to an operation stop command of the disk device, a tab portion formed at one end of a head support arm constituting the actuator is guided to a retracted position, and the tab portion is held at the retracted position. A head holding member,
The escape position is
A head holding plane for holding the tab portion;
A first step side surface formed on the loading side of the head holding plane with a predetermined angle with respect to the head holding plane;
A third slope formed at a predetermined angle with respect to the head holding plane on the unloading side of the head holding plane;
A head holding member comprising: 2. The head according to claim 1, wherein the head holding plane and the first step side surface, and the head holding plane and the third inclined surface are each continuous by a curved surface having a predetermined radius of curvature. Holding member. The curvature radius of the curved surface that makes the head holding plane and the first step side surface and the head holding plane and the third inclined surface continuous is substantially the same as the outer peripheral surface of the tab portion formed at the tip of the head support arm. The head holding member according to claim 2, wherein the head holding member is an arc having the same or larger curvature radius. The predetermined first angle θ ₁ formed by the first step side surface with respect to the head holding plane is 90 ° ≦ θ ₁ ≦ 101 °.
And
The predetermined second predetermined angle θ ₂ formed by the third inclined surface with respect to the head holding plane is 90 ° ≦ θ ₂ ≦ 169 °.
The head holding member according to claim 1, wherein the head holding member is a head holding member. In the direction perpendicular to the rotation center of the rotation shaft of the actuator, the width of the head holding plane is formed to be larger than the width of the tab portion of the head support arm. The head holding member according to any one of claims 1 to 4. A recording medium rotatably disposed around a rotation axis;
A head support arm having a head and a tab portion at one end and rotatable around a first rotation axis parallel to the rotation axis by a first bearing disposed at a position away from the rotation axis; ,
A second bearing disposed between the head and the first bearing and rotatable about a second rotation axis perpendicular to a longitudinal center line of the head support arm;
Two or more abutting portions on the second rotating shaft and abutting on the head support arm or the second bearing;
A leaf spring portion connecting the head support arm and the second bearing;
A ramp portion for holding the tab portion when the head support arm is retracted;
A head holding method in a disk device comprising:
A third inclined surface with which the tab portion abuts, a first step side surface for preventing the tab portion from moving from the retracted position toward the recording medium, and a head holding plane for holding the tab portion at the retracted position. When the tab portion moves to the retracted position in the ramp portion formed with
A force in a radial direction of the recording medium and a direction perpendicular to the radial direction and a biasing force of the leaf spring portion are applied to the head support arm to move the head support arm in the radial direction of the recording medium;
Of the forces acting on the head support arm, after the tab portion is brought into contact with the third inclined surface of the ramp portion by at least the biasing force of the leaf spring portion, the tab portion becomes the retracted position. A method of holding a head, wherein the head is held on a head holding plane. The head support arm has a voice coil connected to the head support arm via a voice coil holder;
The head holding method according to claim 6, wherein the head support arm swings around the first rotation shaft by supplying current to the voice coil and driving the voice coil. Having a crash stop contacting the voice coil holder;
The head holding method according to claim 7, wherein the crash stop restricts excessive swinging of the head support arm. When the tab portion is moved to the retracted position, the voice coil holder is applied to the crash stop before the tab portion abuts against the third inclined surface during the retracting until the tab portion is held at the retracted position. The head holding method according to claim 8, wherein the head is held in contact. A recording medium rotatably disposed around a rotation axis;
A head support arm having a head and a tab portion at one end and rotatable around a first rotation axis parallel to the rotation axis by a first bearing disposed at a position away from the rotation axis; ,
A second bearing disposed between the head and the first bearing and rotatable about a second rotation axis perpendicular to a longitudinal center line of the head support arm;
Two or more abutting portions on the second rotating shaft and abutting on the head support arm or the second bearing;
A leaf spring portion connecting the head support arm and the second bearing;
A ramp portion for holding the tab portion when the head support arm is retracted;
With
A head holding plane that holds the tab portion as a retracted position of the tab portion, and is formed on the recordable area side of the recording medium with respect to the head holding plane and having a predetermined angle with respect to the head holding plane. And a third slope formed on the opposite side of the recordable area of the recording medium with respect to the head holding plane and having a predetermined angle with respect to the head holding plane. Having the lamp part formed,
When the tab portion moves to the retracted position, a force in a radial direction of the recording medium and a direction perpendicular to the radial direction and a biasing force of the leaf spring portion are applied to the head support arm, and the head support arm Is moved in the radial direction of the recording medium,
Of the forces acting on the head support arm, at least by the biasing force of the leaf spring portion, the tab portion is held on the head holding plane which is the retracted position after contacting the third slope of the ramp portion. A disk device characterized by being made. The disk device according to claim 10, wherein the second bearing is a pivot bearing having a pivot as a contact point. The disk apparatus according to claim 10, wherein the pivot is a vertex of a cone or a pyramid. 11. The disk device according to claim 10, wherein the second bearing is a pivot bearing having one point of a curved surface that makes contact as a contact point or a contact ridge line as a contact line. The head support arm has a voice coil connected to the head support arm via a voice coil holder;
11. The disk device according to claim 10, wherein the head support arm swings around the first rotation shaft by supplying current to the voice coil and driving it. Having a crash stop contacting the voice coil holder;
15. The disk device according to claim 14, wherein the crash stop restricts excessive swinging of the head support arm. When the tab portion is moved to the retracted position, the voice coil holder is crashed before the tab portion comes into contact with the third inclined surface until the tab portion is held at the retracted position. The disk device according to claim 15, wherein the disk device abuts against a stop. 11. The disk device according to claim 10, wherein the tab portion of the head support arm has a pressing force to press a head holding plane of the ramp portion when the recording medium stops rotating. The ramp portion is disposed in the vicinity of the outer periphery of the recording medium, and the first magnet is disposed on the opposite side of the recording medium side with respect to the head support arm so as to face the voice coil. The disk device according to claim 10. The ramp portion is disposed in the vicinity of the rotation center of the recording medium, and the second magnet is disposed on the recording medium side with respect to the head support arm so as to face the second voice coil. The disk device according to claim 18. When the tab portion slides on the first step side surface, the friction coefficient between the tab portion and the first step side surface is μ ₁ , and the tab portion slides on the third inclined surface. When the friction coefficient between the tab portion and the third inclined surface is μ ₂ , a predetermined first angle θ ₁ formed by the first step side surface with respect to the head holding plane and the head holding The predetermined second angle θ ₂ formed by the third inclined surface with respect to the plane is 90 ° ≦ θ ₁ ≦ (90 ° + tan ⁻¹ μ ₁ ) with respect to the head holding plane, respectively.
90 ° ≦ θ ₂ ≦ (180 ° −tan ⁻¹ μ ₂ )
The disk device according to any one of claims 10 to 19, wherein the disk device is formed so as to be The predetermined first angle θ ₁ formed by the first step side surface with respect to the head holding plane and the predetermined second angle θ ₂ formed by the third inclined surface with respect to the head holding plane are: 90 ° ≦ θ ₁ ≦ 101 ° with respect to the head holding plane, respectively
90 ° ≦ θ ₂ ≦ 169 °
21. The disk device according to claim 20, wherein the disk device is formed so that

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