JP2005293725A - Inertia latch mechanism and actuator locking mechanism and magnetic disk device using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inertia latch mechanism and an actuator locking mechanism and a magnetic disk device using them which absorb a shock at the time a constituting component of the inertia latch mechanism used in the magnetic disk device occurs collision and suppress occurrence of noise by attenuating excitation force. <P>SOLUTION: The inertia latch mechanism of this invention has an arm member being an inertia lever which latches an actuator and consists of a metal member, and constitutes main shape, and a resin sleeve is fitted to a through hole provided in the arm member, and has a through hole in which a swing shaft can be threaded, and has attenuation action, consisting of a viscoelastic member and a resin projection member is provided at the end part of the arm member, has attenuation action, and consisting of viscoelastic member in an inertia latch mechanism latching the actuator and stays it at a saving position when a shock is applied to the magnetic disk device in the state that the actuator of the device is made to be at the retreating position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inertial latch mechanism that latches an actuator of a magnetic disk device when an external impact is applied to the magnetic disk device, and also includes an inertial latch mechanism, and the actuator is placed in a retracted position when the magnetic disk device is not operating. A highly reliable inertial latch mechanism capable of latching an actuator regardless of which direction the impact swings the actuator, and more particularly to a magnetic disk device including the actuator lock mechanism, The present invention relates to an actuator lock mechanism and a magnetic disk device using the same.

  In a current magnetic disk device, particularly a magnetic disk device mounted on a notebook-type portable personal computer, high reliability against an impact when the magnetic disk device is not operating is required. If the head slider mounted on the actuator moves from the retracted position to the data area on the disk surface due to an impact when the magnetic disk device is not operating, the head slider is attracted to the data area surface or the data area surface is damaged. This can be a fatal failure. There is an actuator lock mechanism as a mechanism for holding the actuator in the retracted position during non-operation and preventing the actuator from swinging due to an impact and moving to the data area surface.

  Further, in recent magnetic disk devices, a head slider load / unload mechanism has been considered for the purpose of preventing the head slider from being attracted to the surface of the evacuation area and enhancing the reliability against the impact. Yes. The load / unload mechanism retracts the head slider in a non-contact manner with respect to the disk surface by holding an actuator on a part called a ramp provided near the outer periphery of the disk when the magnetic disk device is not operating. .

  One actuator lock mechanism uses an inertial latch mechanism. In an actuator lock mechanism using an inertial latch mechanism, the ramp / magnetic lock mechanism of the load / unload mechanism is usually used as an actuator holding mechanism. The inertia latch mechanism operates when an impact is applied to the magnetic disk device, and is a mechanism that latches the actuator using an inertia force generated by the applied impact. This inertial latch mechanism can latch the actuator against a strong impact that cannot be dealt with only by the magnetic lock mechanism or the like. The above-mentioned actuator holding mechanism holds the actuator when a weak impact is applied that prevents the inertial latch mechanism from operating, and increases the reliability of the actuator lock mechanism.

  As an example of an actuator lock mechanism using such an inertia latch mechanism, there is one disclosed in Japanese Patent Application Laid-Open No. 2002-93091 or Japanese Patent Application Laid-Open No. 2003-51165. These prior arts describe that a cushioning material may be provided at a position in contact with the upper and lower surfaces of the inertia arm (inertia lever). Further, it is disclosed that it is constituted by a metal inertia arm (inertia lever) which is concavely fitted on the rotation axis of the inertia arm (inertia lever) and fitted into a protrusion, and further has a protruding shape.

JP 2002-93091 A (summary, FIG. 9) JP 2003-511165 A (Summary, FIG. 3)

  However, since the inertia arms (inertia levers) of the prior art disclosed in Patent Document 1 and Patent Document 2 are made of metal, the inertia arms (inertia levers) are not affected when vibration or impact is applied from the outside. It goes wild and collides with the shaft and bearing holes. In addition, the end of the inertia arm (inertia lever) away from the rotation axis collides with peripheral components. Peripheral parts are usually made of metal, and this impact acts on the disk device as an excitation force with a wide spectrum as if an impact was applied by an impulse hammer, and this adversely affects the positioning system of the actuator lock mechanism. Or contact noise may be generated as a noise due to collision between metals.

  Accordingly, the present invention has been made to solve the above-described problems, and absorbs an impact when a component of an inertial latch mechanism used in a magnetic disk device collides, attenuates an excitation force, and generates noise. It is an object of the present invention to provide an inertial latch mechanism and an actuator lock mechanism for suppressing the above-described problem and a magnetic disk device using the same.

  In order to solve the above-described problem, the inertial latch mechanism according to the present invention latches the actuator when an impact is applied to the magnetic disk device in a state where the actuator of the magnetic disk device is in the retracted position, thereby In inertial latch mechanism that stops in position,

  A latch lever that can swing between an actuator open position and an actuator position about a first swing shaft, and that latches the actuator by moving from the actuator open position to the actuator latch position when the impact is applied And an inertia moment about the second oscillation axis is greater than an inertia moment about the first oscillation axis of the latch lever, and the actuator When an impact that swings in the first direction is applied, it swings in the first direction, engages with the latch lever at the first engaging portion, moves the latch lever to the actuator latch position, Further, when an impact is applied that the actuator swings in the second direction, the actuator swings in the second direction, and the latch lever in the second engaging portion. An inertia lever that engages, moves the latch lever to the actuator latch position, and latches the actuator, and includes an arm member made of a metal member constituting a main shape, and a through-hole provided in the arm member. A resin sleeve made of a viscoelastic member having a damping action and having a through hole that can be inserted through the second swing shaft; and a viscoelastic member having a damping action provided at an end of the arm member. And a resin protrusion member.

  According to the present invention, by adopting the configuration as described above, the impact when the components of the inertial latch mechanism used in the magnetic disk drive collide is absorbed, the excitation force is attenuated, and the generation of noise is suppressed. An inertial latch mechanism, an actuator lock mechanism, and a magnetic disk device using the same can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
An embodiment applied to a magnetic disk device (HDD) which is a disk device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of an internal configuration of a magnetic disk device according to an embodiment of the present invention. The magnetic disk device includes a disk 1 such as a magnetic disk that is a data recording medium, a spindle motor (SPM) 2 that rotationally drives the disk, an actuator 22 on which a head slider 4 that mounts a head is mounted, and an actuator 22 that swings. A voice coil motor (VCM) 23, a crash stop (not shown) that regulates the swing range of the actuator 22, a ramp block 6 provided at a retracted position of the actuator 22, an inertial latch mechanism 7 of the present invention constituting an actuator lock mechanism, etc. Is housed in the enclosure 10 including the base. This magnetic disk device is provided with an actuator lock mechanism using a load / unload mechanism of the actuator 22 and an inertial latch mechanism. When the operation of the magnetic disk device is stopped, the actuator 22 is unloaded to the retracted position When the magnetic disk device is not operating, the actuator 22 is held in the retracted position. The ramp block 6 constitutes the load / unload mechanism and the actuator lock mechanism.

  The disk 1 is fixed to the rotor portion of the spindle motor 2. The disk 1 is rotationally driven around the spindle axis of the spindle motor 2 when the magnetic disk device is operating, and stops rotating (stills stationary) when the magnetic disk device is not operating. On the surface of the disk 1, tracks on which data and servo information are recorded are concentrically arranged.

  The actuator 22 has a head arm and a coil arm, and is fitted to the swing shaft so as to be swingable. That is, it is provided so as to be able to rotate about the swing axis. The head arm and the coil arm are arranged so as to be opposite to each other with the swing shaft interposed therebetween. The coil arm includes an outer arm and an inner arm. The head arm has a carriage arm and a suspension arm suspended on the carriage arm.

  The suspension arm has a tab for retracting to the ramp block 6. The tab is a portion that is held by the ramp block 6 when the head arm moves to the retracted position. The tab is formed with a convex portion that contacts the lamp block 6. A head slider 4 is mounted on the suspension arm.

  The head slider 4 is attached to the head arm so as to face the upper surface and the lower surface of the disk 1, respectively, and is connected to a control unit (not shown) by trace wiring or the like. The head slider 4 includes a magnetic head that records data from a control unit (not shown) on a track on the surface of the disk 1 and reads the data recorded on the track and sends it to the control unit.

  The VCM 23 includes a voice coil 51 mounted on the inner surface of the coil arm, an upper yoke 23a and a lower yoke (not shown), a permanent magnet (not shown) attached to the lower surface of the upper yoke 23a, and the like. The voice coil 51 is supplied with a drive current from a control unit (not shown). The coil arm is disposed in a space sandwiched between the upper yoke 23a and the lower yoke.

  The lamp block 6 has a plurality of lamps protruding in the horizontal direction from the side surface of the lamp support. Each lamp has a composite plane on the upper and lower sides. These composite planes are provided corresponding to the respective tabs. The upper composite plane includes a first inclined plane and a top plane. These composite planes are directed from the side closer to the outer periphery of the disk 1 to the side farther from the outer side of the disk 1 along the direction of movement of the tab projections accompanying the swing of the suspension arm during unloading, that is, generally along the radial direction of the disk 1. Arranged in the above order. The lamp block 6 is fixed to the enclosure 10 with screws (see FIG. 1). The actuator 22, the VCM 23, and the ramp block 6 constitute a load / unload mechanism.

  2 and 3 are enlarged views of the periphery of the inertial latch mechanism 7 in FIG. 1, 2 and 3, the inertia latch mechanism 7 swings around an inertia arm (inertia lever) 7 b that can oscillate (rotate) about a swing shaft 7 bb and another swing shaft. A latch lever 7a that can move (rotate) and a tip magnet (not shown) for holding the latch lever 7a in the arm open position. The inertia moment of the inertia arm (inertia lever) 7b around the swing shaft 7bb is larger than the inertia moment of the latch lever 7a around another swing shaft.

  The inertia arm (inertia lever) 7b includes a first engagement engagement portion for engaging with the latch lever 7a at the first engagement projection, and a second engagement portion for engagement at the second engagement projection. Is formed. The latch lever 7a includes a latch arm and an auxiliary latch arm that extend at an obtuse angle with respect to the swing axis. The auxiliary latch arm is formed with a magnetic member that is attracted to the chip magnet. A latch protrusion is formed on the latch arm of the latch lever 7a. When the latch lever 7a moves to the actuator latch position, the latch 22 engages with the tip of the inner arm of the actuator 22 to latch the actuator 22.

  When the latch lever 7a is in the actuator open position, the first engagement portion of the inertia arm (inertia lever) 7b is a key portion formed at the first engagement protrusion with the inner surface of the auxiliary arm facing the actuator 22 side. The second engagement portion is in contact with the side surface of the latch arm opposite to the actuator 22 at the second engagement protrusion, or Or slightly away from the side. The inertial latch mechanism 7 and the ramp block 6 constitute an actuator lock mechanism.

  When the magnetic disk device stops operating, a control unit (not shown) sends a drive current to the voice coil 51 of the VCM 23 to unload the head arm of the actuator 22 to the retracted position. Further, when the magnetic disk apparatus starts operation, the head arm is loaded from the retracted position, the head slider 4 is moved from the surface of the disk 1 where the rotation operation is started, and further read from the magnetic head of the head slider 4. Based on the servo data, the head slider 4 is moved onto a desired data track. FIG. 1 shows a state in which the head slider 4 is unloaded to the retracted position.

  When the magnetic disk device is not operating, the head arm and the head slider 4 of the actuator 22 are unloaded to the retracted position. When the head arm is in the retracted position, the tab of the suspension arm is held by the ramp block 6. Further, the disk 1 is stationary. When unloading the head arm, the tab of the suspension arm first comes into contact with the first inclined surface, climbs while sliding on the first inclined surface, and slides on the top deformed surface.

  In the ramp block 6, when the head arm is unloaded in the retracted position and the tab is held in the ramp block 6, the head arm is moved from the retracted position to the disk against a weak impact so that the inertial latch mechanism 7 does not operate. It has a function as an actuator holding mechanism that prevents the head arm from moving to one side or the opposite side and holds the head arm in the retracted position.

  Next, an actuator lock operation when an impact is applied to the magnetic disk device during non-operation will be described. At this time, the inertia latch mechanism 7 operates as follows to latch the actuator 22 and prevent the head arm and the head slider 4 from entering the space where the disk 1 is disposed.

  Next, the operating principle of the inertial latch mechanism 7 of this embodiment will be described. Parts such as the actuator 22 that are swingably provided on the swing shaft are subjected to linear acceleration and angular acceleration due to external impact applied to the magnetic disk device. If the linear acceleration received by the actuator 22 due to the impact is L and the angular acceleration is A, the force (translational force) caused by the linear acceleration L acts on the mass center of gravity Gc of the actuator 22, and the force caused by the angular acceleration A (couple force) ) Works around the oscillation axis. Hereinafter, linear acceleration due to the impact is referred to as linear impact acceleration, and angular acceleration due to the impact is referred to as impact angular acceleration.

  The direction of the impact angular acceleration A is the direction when the magnetic disk device is a stationary system. The direction of the linear impact acceleration L coincides with the direction of the linear acceleration component received by the magnetic disk device due to the impact. Further, since the impact angular acceleration A is generated by an inertial force that tries to keep the actuator 22 at the original position, the angular acceleration component (center of gravity Gd of the magnetic disk device) is received by the magnetic disk device due to the impact. The direction is reversed. Therefore, when the direction of the angular acceleration component received by the magnetic disk device is clockwise with respect to the mass center of gravity Gd of the magnetic disk device, the impact angular acceleration A counterclockwise with respect to the swing shaft 21 acts on the actuator 22. When a linear impact acceleration L is applied to the actuator 22, linear acceleration in the same direction as the linear impact acceleration L is also applied to the inertia arm (inertia lever) 7b and the latch lever 7a. When the counterclockwise impact angular acceleration A acts on the actuator 22, counterclockwise impact angular acceleration acts on the inertia arm (inertia lever) 7b around the swing shaft 7bb, and the latch lever 7a swings. Counterclockwise impact angular acceleration works around the axis.

  When the linear acceleration and the angular acceleration are constant, the magnitude of the translational force depends on the mass of the part, and the magnitude of the couple depends on the magnitude of the moment of inertia around the swing axis of the part. Considering a circle centering on the swing axis and passing through the mass centroid, the tangential component at the mass centroid of this circle is the effective component, and the normal component at the mass centroid is the invalid component. It is the effective component of linear acceleration (translational force) and angular acceleration (couple) that are responsible for the swinging of the parts. The ineffective component of linear acceleration (translation force) does not contribute to the swinging of the component. Therefore, the resultant force of the couple and the effective component of the translational force is a torque that causes the component to swing. In the actuator 22, the resultant force of the couple due to the impact angular acceleration A and the force due to the effective component Le of the linear impact acceleration L is the torque T that causes the actuator 22 to swing. Coupled by impact angular acceleration A and effective component Le

Both of these forces act in a direction that causes the actuator 22 to swing counterclockwise, so that the actuator 22 swings counterclockwise. Similarly, torque is applied to the inertia arm (inertia lever) 7b so as to swing counterclockwise about the swing shaft 7bb, and the latch lever 7a swings counterclockwise about the swing shaft. The torque to try to work works. If the linear impact acceleration is in the direction of L ′ in the figure, the force due to the effective component of the linear impact acceleration L ′ acts in a direction that causes the actuator 22 to swing clockwise. Therefore, the magnitude of the torque T for swinging the actuator 22 varies depending on the direction of the linear impact acceleration L even if the magnitude and direction of the impact angular acceleration A and the magnitude of the linear impact acceleration L are constant. In other words, the magnitude of the torque T that causes the actuator 22 to swing varies depending on the positional relationship between the swing axis and the mass center of gravity Gc even if the magnitude and direction of the impact angular acceleration A and the linear impact acceleration L are constant. . Further, when the force due to the effective component of the linear impact acceleration L ′ is greater than the couple due to the impact angular acceleration A, the direction of the torque T is reversed. However, the above is only when the swing axis and the mass center of gravity Gc do not match. When the swing axis and the mass center of gravity Gc match, the linear impact acceleration L is the actuator. 22 is not involved in swinging. Similarly, in the inertia arm (inertia lever) 7b and the latch lever 7a, when the swing axis and the center of mass of the mass do not coincide with each other, the magnitude of the torque acting on the lever depends on the direction of the linear impact acceleration or the swing. It depends on the positional relationship between the dynamic axis and the mass center of gravity.

Details of the inertia latch mechanism, actuator lock mechanism, and magnetic disk apparatus of the present invention will be described below with reference to the drawings.
FIG. 1 is a view for explaining the structure of a magnetic disk apparatus according to the present invention.
In the magnetic disk apparatus of the present invention, the magnetic head on the slider 4 and the disk 1 collide with each other due to unexpected vibration and impact when the apparatus is not operating, and both parts are damaged or rubbed against each other to generate dust. In order to prevent this, the magnetic head on the slider 4 is retracted from the disk 1. The retracted magnetic head on the slider 4 is positioned on the ramp block 6 and moves from the ramp block 6 onto the disk 1 simultaneously with the start of the operation of the magnetic disk device.

  When the magnetic head on the slider 4 is in the retracted position, if the ramp block 6 is subjected to a rotational shock or rotational vibration force greater than the holding force for supporting the magnetic head on the slider 4 at a predetermined position, the magnetic disk drive is applied. The inertial force moves the magnetic head on the slider 4 toward the disk 1, and the magnetic head on the slider 4 jumps out of the ramp block 6 and rides on the disk 1.

Therefore, an inertia latch mechanism is a mechanism for preventing the magnetic head on the slider 4 from riding on the disk 1 when the above force is applied to the magnetic disk device.
The structure of the inertial latch mechanism 7 includes an inertia arm (inertia lever) 7b, a latch lever 7a, and a tip of the inner arm of the actuator 22.
The inertial latch mechanism will be described with reference to FIGS.
FIG. 2 is a schematic diagram showing the positional relationship of each component of the inertial latch mechanism when the magnetic disk device is not operating. When the magnetic disk device is in a non-operating state, the magnetic head on the slider 4 is positioned on the ramp block 6, and the side of the actuator 22 on which the tip of the inner arm is provided is pressed against and supported by a rubber material stopper. Yes.

  The inertia arm (inertia lever) 7b and the latch lever 7a are attached with the center 7bb of the respective rotating shafts lightly constrained to the housing 10 so that free movement is possible. The inertia lever 7b is inserted between the mating protrusion and the second engagement portion protrusion, and the first engagement protrusion of the latch lever 7a and the first engagement portion of the inertia lever 7b are also connected to the second engagement of the latch lever 7a. It arrange | positions so that protrusion and the 2nd engaging part of the inertia lever 7b may engage.

FIG. 3 is a diagram showing a state in which an impact is received in the direction of the rotation axis when the magnetic disk device is in a non-operating state.
The detailed structure and operation of the inertia arm (inertia lever) 7b of this embodiment will be described with reference to FIGS. As shown in FIG. 2, a resin, particularly a resin sleeve 7bd made of a viscoelastic member having a damping action, and a vibration / impact from the outside are applied as a part for receiving a rotating shaft 7bb of an inertia arm (inertia lever) 7b. The resin, particularly this resin, has a damping action 7be made of a viscoelastic member that has a damping action on the part that is in contact with the surrounding parts, especially at each end of the inertia arm (inertia lever) 7b away from the rotating shaft 7bb. It has a structure to add.

  The resin slave 7bd and the resin protrusion 7be are formed so as to protrude in the direction of the rotation shaft 7bb from the arm member 7ba made of a metal member constituting the main shape of the inertia arm (inertia lever) 7b. The through hole provided in the arm member 7b is filled and attached. In particular, the resin slave 7bd is further provided with a through hole for inserting the rotation shaft 7bb. Further, the through holes provided in the arm member 7ba for attaching the resin protrusion 7be are respectively provided at the end portions of the corresponding arm member 7ba across the rotation shaft 7bb.

  Next, FIG. 3 shows the situation at the time of collision of the inertia arm (inertia lever) 7b according to this embodiment, and its operation will be described. When the magnetic disk device receives an impact in the direction of the rotation axis, that is, the vertical direction, the rotation shaft 7bb and the resin sleeve 7bd collide with each other. Further, the resin protrusion 7be provided at the end of the inertia arm (inertia lever) 7b collides with the enclosure 10 serving as a base. At this time, the resin sleeve 7bd and the resin projection 7be absorb the impact when they collide, attenuate the excitation force, and suppress the generation of noise.

  Here, FIG. 4 shows the results of evaluating the bending elastic modulus of the resin used for the resin sleeve 7bd and the resin protrusion 7be of this embodiment and the positioning accuracy when vibration is applied from the outside. The vertical axis of this graph indicates the positioning accuracy of the inertia arm (inertia lever) 7b, and the larger the value, the worse the accuracy. Further, the horizontal axis indicates the bending elastic modulus of the resin part material mounted on the inertia arm (inertia lever) 7b. As shown in FIG. 2, when the gap between the resin protrusion 7be attached to the end of the inertia arm (inertia lever) 7b and the upper yoke 23a provided on the upper part is 7bf, this gap is 0.2 mm. Yes, the attenuation coefficient is about 0.1.

  As a result of evaluation using several kinds of resin materials for the resin sleeve 7bd and the resin protrusion 7be, it was found that there is a strong positive correlation between the bending elastic modulus and the positioning accuracy. In the magnetic disk apparatus according to the present embodiment, since the apparatus specification can be satisfied with the target positioning accuracy 1, it has been found that a material having a bending elastic modulus of 1000 MPa or less may be used. Accordingly, the resin sleeve 7bd and the resin protrusion 7be are configured to have a bending elastic modulus of 1000 MPa or less.

  FIG. 5 shows the calculation results. The vertical axis shows the acceleration given to the magnetic disk device side when the inertia arm (inertia lever) 7b vibrates and collides, and the horizontal axis shows the elastic constant (bending elastic modulus, thickness, cross-sectional area) of each resin member. Calculated in consideration). From this graph, it was found that there is a strong correlation between the flexural modulus and the generated acceleration, as described above. That is, it has been found that vibration and noise can be suppressed by lowering the flexural modulus if the damping rate and clearance are the same. In other words, when the equivalent of 2500 MPa is used, the acceleration value can be reduced to about 1/5 and the noise power can be reduced to 1/5. It becomes possible to do.

  By adopting the configuration described above, an inertia latch mechanism and an actuator lock mechanism that absorb the shock when the components of the inertia latch mechanism used in the magnetic disk device collide, attenuate the excitation force, and suppress the generation of noise. In addition, a magnetic disk device using the same can be provided.

  Needless to say, the present invention is not limited to the magnetic disk device described above, but can be applied to other disk devices using a rotary actuator, for example, a magneto-optical disk device and an optical disk device.

1 is a block diagram showing an outline of a system configuration in a magnetic disk device according to an embodiment of the present invention. The figure which shows the structure of the inertial latch mechanism which concerns on embodiment of this invention. The figure which shows the state which received the external impact in the inertial latch mechanism which concerns on embodiment of this invention. The figure which shows the relationship between the bending elastic modulus of resin used for the resin sleeve which concerns on embodiment of this invention, and positioning accuracy when a vibration is applied from the outside. The figure which showed the relationship between the elastic constant of resin which concerns on embodiment of this invention, and impact acceleration.

Explanation of symbols

1 …… Disk device 2 …… Spindle motor (SPM)
4 ... Head slider 6 ... Ramp block 7 ... Inertia latch mechanism 7a ... Latch lever 7b ... Inertia latch (inertia lever)
7ba: Arm member 7bb: Rotating shaft 7bd ... Resin sleeve 7be ... Resin protrusion 7bf ... Clearance gap between resin protrusion and upper yoke 10 ... Enclosure (base)
22 …… Actuator 23 …… Voice coil motor (VCM)
23a …… Upper yoke 51 …… Voice coil

Claims (6)

In an inertial latch mechanism that latches the actuator when an impact is applied to the magnetic disk device in a state where the actuator of the magnetic disk device is in the retracted position, and stops at the retracted position.
A latch lever that can swing between an actuator open position and an actuator position about a first swing shaft, and that latches the actuator by moving from the actuator open position to the actuator latch position when the impact is applied When,
The actuator is capable of swinging about a second swing shaft, and the moment of inertia about the second swing shaft is greater than the moment of inertia of the latch lever about the first swing shaft, and the actuator is When an impact that swings in the direction of is applied, it swings in the first direction, engages with the latch lever at the first engaging portion, moves the latch lever to the actuator latch position, and When an impact is applied that the actuator swings in the second direction, the actuator swings in the second direction, engages with the latch lever at the second engaging portion, and moves the latch lever to the actuator latch position. An inertia lever that latches the actuator, and is fitted into an arm member made of a metal member constituting a main shape, and a through hole provided in the arm member, and the second lever An inertia lever having a resin sleeve made of a viscoelastic member having a damping action having a through-hole through which a moving shaft can be inserted, and a resin projection member made of a viscoelastic member having a damping action provided at an end of the arm member And an inertia latch mechanism.   2. The inertia latch mechanism according to claim 1, wherein the resin sleeve has a structure projecting vertically from the through hole provided in the arm member in the second swing axis direction.   The resin protrusion member is filled in a mounting through hole provided at an end of the arm member of the inertia lever, and has a structure protruding in the vertical direction in the second swing axis direction. The inertial latch mechanism according to claim 1. The inertial latch mechanism according to claim 1, wherein a bending elastic modulus of a viscoelastic member constituting the resin slave provided in the inertial lever is 1000 MPa or less. An inertial latch mechanism according to any one of claims 1 to 2,
An actuator lock mechanism comprising: an actuator holding mechanism that holds the actuator in the retracted position against a weak impact that the inertia latch mechanism does not work. A disk recording medium;
A head slider having a head element for recording data on the disk recording medium and reading the recorded data;
A head arm on which the head slider is mounted;
An actuator that unloads the head arm to the retracted position and loads the head arm from the retracted position so that the head slider approaches the surface of the disk recording medium;
A magnetic disk drive comprising the actuator lock mechanism according to claim 5.

Images