JPH0136195B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic loading mechanism for a slider in a magnetic disk device, a floppy disk device, etc., and in particular, it relates to an automatic loading mechanism for a slider in a magnetic disk device, a floppy disk device, etc. This invention relates to an automatic loading mechanism.

[Conventional technology]

The floating head slider stably floats about 0.2 μm above the disk surface when rotating at a constant speed. The biggest technical problem with this slider is to avoid collision with the disk surface, and high reliability is particularly required in operations in unsteady conditions such as when the slider lands on the ground. As a countermeasure, the IBM Technical
Disclosure Bulletin (IBM Technical Disclosure Bulletin) Vol. 25 No. 10 discloses that a shape memory alloy member is used as a driving part of a slider loading means.

[Problem that the invention seeks to solve]

In the above structure, the arm to which the head is attached and the shape memory alloy member operate in an integrated manner, making it difficult to apply a constant pressing force to the slider. In addition, since the driving force of the shape memory alloy member is directly applied against the spring force of the pressing member that supports the slider, the pressing force and the deformation spring force of the shape memory alloy member cannot be significantly changed. Movement is unstable and operation speed is slow.

An object of the present invention is to provide an automatic slider loading mechanism that can apply a smooth and stable slider pressing force.

[Means for solving problems]

The above object is to use a shape memory alloy member that exhibits a shape memory effect based on thermoelastic martensitic phase transformation, and a spring force disposed to resist the recovery force of the shape memory alloy member. This is achieved by constructing the spring member with a spring member.

[Effect]

When the shape memory alloy member is energized and heated, it lifts the slider via the load arm against the spring member and brings it into an unloaded state. Further, the shape memory alloy member brings the slider into a loaded state by being cooled.

〔Example〕

First, the shape memory effect based on thermoelastic martensitic transformation will be explained. Shape memory alloys such as Ti-Ni alloys have an austenite crystal structure (mother phase) above the phase transformation point. When the temperature drops below the phase transformation point, this phase changes to martensitic phase,
Easily deformed by small external forces. and,
When heated again above the transformation point, this martensite phase elastically returns to the original austenite phase (reverse transformation) according to a certain regular crystal arrangement law.
At this time, it has the property of exhibiting extremely high resilience.

By using an elastic spring as a bias force for martensitic phase deformation at low temperatures,
Reversible operation associated with thermal cycles can be performed.

The present invention focuses on the phenomenon that the martensitic transformation site of a shape memory alloy under elastic spring load stress gradually progresses as it cools, and utilizes the continuous change in recovery force that occurs at this time.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

A magnetic head 2 attached to a part of the slider 1 writes data on a rotating magnetic disk 3 and reads data written on the magnetic disk 3. This slider 1 is attached to the tip of a load arm 5 as a pressing member with a gimbal 4 interposed therebetween. The load arm 5 as a pressing member has an elastic force for pressing the slider 1 against the magnetic disk surface with a constant pressure. Further, the load arm 5 is attached to a movable guide bar 6 at its base, allowing the slider 1 to access any track on the magnetic disk surface. A loading means 7 that opposes the pressing force of the load arm 5 is attached to the guide bar 6 . This loading means 7 includes a pin 8 for lifting the load arm 5 upward, and an elastic leaf spring as an elastic member provided on a support base 9 so as to constantly apply a downward pressing force to the pin 8. 10, and Ni-Ti which is provided on this support stand 9 and has a shape memory recovery force acting in a direction opposite to the elastic force of this elastic leaf spring 10.
It is composed of a shape memory alloy plate 11 as an alloy-based shape memory alloy member, and a current-carrying wire (not shown) for supplying electricity to the shape memory alloy plate 11 and heating the shape memory alloy plate 11 to a transformation point or higher. ing. The pin 8 passes through the load arm 5 in order to lift the load arm 5 upward, has a hook portion at its lower end that engages with the load arm 5, and has a shape memory alloy plate 11 at its upper end. It has a hook portion that engages with.

Next, loading and unloading operations will be explained using FIGS. 2 and 3. FIG. 2 shows the loading and unloading means before the disk rotation starts. In this initial state, the shape memory alloy plate 11 is in the martensitic phase, and the yield force is set to be smaller than the elastic force of the elastic leaf spring 10. Therefore, the pin 8 is It is pushed down. Therefore, the load arm 5 is in a non-contact state with the lower end hook of the pin 8.

Immediately before starting rotation of the magnetic disk, electricity is applied to the shape memory alloy plate 11 to heat the shape memory alloy plate 11 to a temperature higher than the phase transformation point. As a result, the shape memory alloy plate 11 elastically returns to the austenite phase (reverse transformation), and a shape memory recovery force greater than the elastic force of the elastic leaf spring 10 acts upward. The upward shape memory restoring force of the shape memory alloy plate 11 causes the pin 8 to move upward, and in conjunction with this, the lower end hook of the pin 8 engages the load arm 5 and lifts it upward. That is, an unloading operation is performed. FIG. 3 shows this state. In this state, the magnetic disk is started to rotate and continues to rotate up to a predetermined rotation speed. When the magnetic disk reaches a predetermined rotational speed, the heating of the shape memory alloy plate 11 is stopped. Thereby, the electrical heating of the shape memory alloy plate 11 is stopped. As a result, the shape memory alloy plate 11
is cooled and martensitic transformation occurs, and the upward restoring force gradually decreases and becomes smaller than the elastic force of the elastic leaf spring 10. This shape memory alloy plate 11
Due to the decrease in the yield force of the pin 8, the pin 8 is pushed back downward, and accordingly, the load arm 5, which is engaged with the lower end hook of the pin 8, is released from the upward lifting force and moves the slider toward the magnetic disk. Press it onto the surface with constant pressure. That is, a loading operation is performed.

In this embodiment, the martensitic transformation region of the shape memory alloy plate 11 gradually progresses and expands as the temperature decreases, so that the slider lands extremely smoothly. Furthermore, since the loading and unloading operations are performed by the spring force of the elastic leaf spring 10 and the recovery force of the shape memory alloy plate 11,
The force can be greater than the pressing force of the slider. Thereby, the operation of the slider can be stabilized and the operation speed can be increased.

Furthermore, since the loading means 7 having the shape memory alloy plate 11 and the elastic leaf spring 10 and the load arm 5 to which the slider 1 is attached are not integrated in their operation, a constant pressing force is always applied to the slider 1 during loading. can be granted. This means that even if the pressing force of the shape memory alloy plate 11 fluctuates due to environmental temperature or aging, or if the pressing force fluctuates due to insufficient precision adjustment during assembly, the load arm 5 This is because fluctuations are not transmitted.

In addition, since the shape memory alloy plate 11 and the load arm 5 are not integrated, the shape memory alloy plate 11
It becomes easy to energize and heat, and operation control becomes easy.

Further, since the driving source members of the loading means 7 are only the elastic leaf spring 10 and the shape memory alloy plate 11, there is an effect that cost can be reduced and assembly can be facilitated.

Next, another embodiment of the present invention will be described with reference to FIGS. 4 to 14. The embodiment shown in FIG. 4 is shown in FIG.
The elastic member and the shape memory alloy member in the embodiment explained in FIG.
It has been replaced with 3. The shape memory alloy coil 13 has a memorized shape that expands when heated above the transformation point.

In this embodiment, an elastic compression spring 12 is disposed between the middle hook of the pin 8 and the support 9, and a shape memory alloy coil 13 is disposed between the upper hook of the pin 8 and the support 9. It is arranged. Even with this configuration, loading and unloading operations similar to those of the embodiment shown in FIGS. 1 to 3 can be performed and similar effects can be obtained.

The embodiment shown in FIG.
This is an example implemented with consideration given to application to a magnetic disk device having. Shape memory alloy coil 14 as a shape memory alloy member that shrinks when heated above its transformation point
is installed between elastic leaf springs 15 and 16 as elastic members, and below the transformation point, the elastic leaf springs 15 and 1
6 is an example in which a bias force acts to stretch the shape memory alloy coil 14. In this embodiment, when the shape memory alloy coil 14 is heated above its transformation point, it contracts against the spring force of the elastic leaf springs 15 and 16. As a result, the load arm 5 moves via the pin 8 connected to the elastic leaf springs 15 and 16, and an unloading operation is performed.

Further, when the current heating to the shape memory alloy coil 14 is stopped, the shape memory alloy coil 14 is cooled down to a temperature below the phase transformation point, and its recovery power gradually decreases. As a result, the pin 8 is connected to the elastic leaf spring 1
The engagement with the load arm 5 is released by spring forces 5 and 16, and the slider 1 is pressed onto the magnetic disk surface with a constant pressure. That is, a loading operation is performed.

In the embodiment shown in FIG. 6, a silicone resin 17 is used as an elastic member that applies a bias force, and is coated on the outside of a shape memory alloy wire 18 as a shape memory alloy member. The figure shows the initial stopped state, and when the magnetic disk starts rotating, the shape memory alloy wire 18 is energized to cause the shape memory alloy wire 1
8 is heated above the transformation point and a large recovery force acts upward, moving the load arm 5 upward and pushing up the slider 1. In this embodiment, in addition to being able to significantly reduce the number of components, silicone resin 17 is used at the contact point with the load arm 5.
It also has excellent vibration resistance.

In addition, the entire shape memory alloy wire is made of silicone resin 17
This has the effect of lowering the heat transfer coefficient to the outside temperature and making it easier to heat.

The embodiment shown in FIG. 7 uses a plate spring 19 as the elastic member that applies the bias force. The figure shows the initial stopped state, and when the magnetic disk starts rotating, the shape memory alloy plate 20 as a shape memory alloy member is heated by electricity, and the recovery force of the shape memory alloy plate 20 acts upward, pushing the slider 1. increase. This embodiment has the advantage of being extremely thin.

In the embodiment shown in FIGS. 8 to 10, the slider 1
The push-up force is applied to the portion of the load arm 5 on the guide bar 6 side, and both figures show the initial stopped state. In these embodiments, the support 9 of the loading means 7
is rotatably supported on the guide bar 6 by a pin 21. The load arm 5 is attached to this support stand 9. In the embodiment shown in FIG. 8, a U-shaped shape memory alloy wire 22 is used as a shape memory alloy member, a tension spring 23 is used as an elastic member that applies a bias force, and these are arranged between a guide bar 6 and a support base 9. It is set up. When the magnetic disk starts to rotate, when the U-shaped shape memory alloy wire 22 is heated by electricity, a restoring force acts in a direction in which it expands against the tension spring 23. As a result, the support base 9 rotates around the pin 21 and pushes up the slider 1. In this embodiment, since no external force is applied to the load arm 5, there is an effect that no distortion occurs.

In the embodiment shown in FIG. 9, a compression spring 24 is used as an elastic member that applies a bias force, a shape memory alloy wire 25 is used as a shape memory alloy member, and these are arranged between a guide bar 6 and a support base 9. ing. Further, the guide bar 6 is provided with the above-mentioned shape memory alloy wire 25.
A heating element 26 is provided as a heating means.

When the rotation of the magnetic disk starts, the shape memory alloy wire 25 is heated by passing heat through the heating element 26. As a result, a restoring force acts on the shape memory alloy wire 25 in the direction of expanding it against the spring force of the compression spring 24. As a result, the support base 9 rotates around the pin 21 and pushes up the slider 1. In this embodiment, since no external force is applied to the load arm 5, there is an effect that no distortion occurs. Furthermore, since the heating element 26 is provided separately, there is no need to directly heat the shape memory alloy wire 25 with electricity, and the shape memory alloy wire 25 can be easily attached.

The embodiment shown in FIG. 10 is constructed so that information can be written and read on both the front and back surfaces of the magnetic disk 3 using the magnetic heads 2, 2.

In this embodiment, two support stands 9, 9 are rotatably supported on the guide bar 6 by pins 21. A load arm 5 having a slider 1 at its tip is attached to each of the supports 9, 9. A tension spring 27 as an elastic member for applying a bias force is disposed between the supports 9, 9. Further, a shape memory alloy coil 28 as a shape memory alloy member is disposed between the guide bar 6 and the intermediate point of the above-mentioned tension spring 27. The location of the shape memory alloy coil 28 is selected so that the two supports 9, 9 rotate in the same way around the pin 21.

When the magnetic disk starts rotating, when the shape memory alloy coil 28 is energized and heated, the shape memory alloy coil 28 contracts, and the shape memory alloy 28 and the tension spring 2
7 is moved to the side opposite to the slider from the center of rotation of both support stands 9, 9. As a result, the load arms 5, 5 are rotated by the spring force of the tension spring 27, and lift the sliders 1, 1. According to this embodiment, since no external force is applied to the load arm 5,
This has the effect of not causing distortion. Furthermore, two sliders can be loaded and unloaded with one shape memory alloy member, and since it is a dorug mechanism, it has the effect of being stable even when the slider is lifted up.

The embodiment shown in FIG. 11 is constructed so that information can be written and read simultaneously on two magnetic disks 3, 3 using two magnetic heads 2, 2. In this embodiment, the support base of the loading means 7 consists of an outer cylinder 9' slidably supported on the guide bar 6. Further, the slider side end 9a' of this outer cylinder 9' is formed with an inclined part, and when the outer cylinder 9' slides in the slider direction, it engages with the hotter 31 formed on the load arm 5. and the load arm 5 is rotated. A compression spring 32 as an elastic member for applying a bias force and a shape memory alloy coil 33 as a shape memory alloy member are disposed between the guide bar 6 and the outer cylindrical body 9' serving as a support base. The figure shows an initial stopped state in which the sliders 1, 1 are pressed onto the surfaces of the magnetic disks 3, 3 by the spring force of the compression spring 32.

When the magnetic disk starts rotating, the shape memory alloy coil 33 expands against the spring force of the compression spring 32, and slides the outer cylinder 9' toward the cylinder. As a result, the inclined end portion of the outer cylindrical body 9' engages with the hotter 31, rotates the load arm 5, and pushes the slider 1 up from the magnetic disk surface. According to this embodiment, since the driving force of the loading means 7 is applied in a direction parallel to the magnetic disk surface, the loading means can be made very thin.

The embodiment shown in FIG. 12 is similar to FIG.
It is constructed so that information can be written and read on both the front and back surfaces of the magnetic disk 3 using magnetic heads 2, 2, and the figure shows both sliders 1, 1.
The initial state is shown in which the disk is pressed onto the magnetic disk surface. On the support base 9 of the loading means 7, a shape memory alloy ring 34 as a shape memory alloy member is disposed between the load arms 5, 5. When the shape memory alloy ring 34 is not heated and the temperature is below the phase transformation point, it has an elliptical shape as shown in the figure, and its shape is selected so that it has a slight gap with the load arms 5, 5. A tension spring 3 is used as an elastic member for applying a bias force.
5 has both ends fixed in the short diameter direction of the shape memory alloy ring 34. In addition, the support stand 9 has
A heating element 36 is provided for heating the shape memory alloy ring 34.

When the rotation of the magnetic disk starts, the shape memory alloy ring 34 is heated by energizing the heating element 36. As a result, a large recovery force acts on the shape memory alloy ring 34 against the spring force of the tension spring 35, and the shape changes from an elliptical shape to a circular shape. The shape memory alloy ring 34 engages with the load arms 5, 5 during the transformation from the elliptical shape to the circular shape, gradually rotates the load arms 5, 5, and pushes the sliders 1, 1 from both the front and back sides of the magnetic disk. increase.

According to this embodiment, two sliders can be loaded and unloaded with one shape memory alloy member. Furthermore, since the shape memory alloy ring, tension spring, and heating element are integrated, assembly and installation are extremely easy.

FIG. 13 is shown for reference as an example of a structure related to the present invention. In this reference example, a recess 37 is provided at the root of the load arm 5, and the recess 37 acts as an elastic member to buckle and deform out of plane. shape memory alloy coil 3
8 and 39 are engaged. When either the shape memory alloy coil 38 or 39 is heated, it expands and presses into the recess 37 portion. This figure shows a state in which the load arm 5 is pushed upward by pressing the recess 37 from above. In this example, even if heating of both of the two shape memory alloy members is stopped, the movement of the one heated last is maintained, resulting in a flip-flop effect.

FIG. 14 is shown for reference as another example of a structure related to the present invention. In the reference example shown in FIG. 14, the load arm 5 is formed as an elastic member so that the center is curved upward, and the shape is a shape memory alloy member that memorizes a downward curved shape. Memory alloy plates 40 and 41 are bonded together as shown in the figure. By changing this curved shape, the tip of the load arm 5 can be directed downward or upward. This reference example has the advantage of requiring only a very small thin piece of shape memory alloy member and being easy to assemble.

〔Effect of the invention〕

As described above, according to the present invention, the slider pressing force can be made smooth and stable, and a constant pressing force can be applied to the slider during loading.

[Brief explanation of drawings]

Figures 1 to 3 are diagrams for explaining one embodiment of the present invention, where Figure 1 is a side view, Figure 2 is a sectional view of the loading means before starting disk rotation, and Figure 3 is when starting disk rotation. 4, 5, 6, 7, 8, 9
10, 11, and 12 are diagrams illustrating other embodiments of the present invention, and FIGS. 13 and 14.
The figure is a diagram showing a structure related to the present invention for reference. DESCRIPTION OF SYMBOLS 1...Slider, 2...Magnetic head, 3...Magnetic disk, 4...Gimbal, 5...Load arm, 6...Guide bar, 7...Loading means, 8...Pin, 9...Support stand ,10,15,1
6... Elastic leaf spring, 11, 20... Shape memory alloy plate, 12... Elastic compression coil spring, 13, 14,
28... Shape memory alloy coil, 18, 22, 25
...Shape memory alloy wire, 34...Shape memory alloy ring.

Claims (1)

[Scope of Claims] 1. A slider equipped with a magnetic head for writing information on a disk and reading information from the disk, and a slider that is fixed at the tip and that applies a pressing force to the slider onto the disk surface. A pressing member for applying the pressing force, and a loading means for a slider provided to oppose the pressing force of the pressing member, and the loading means for the slider exhibits a shape memory effect based on thermoelastic martensitic phase transformation. It has a shape memory alloy member and an elastic member having a spring force that resists the recovery force of the shape memory alloy member, and during loading, the force by the shape memory alloy member and the elastic member is not transmitted to the pressing member,
An automatic slider loading mechanism characterized in that the automatic slider loading mechanism is configured to transmit force from the shape memory alloy member and the elastic member to the pressing member during unloading. 2. The loading means includes a support base provided on the guide bar to which the pressing member is attached, a shape memory alloy member attached to the support base, and a spring force applied against the recovery force of the shape memory alloy member. The slider automatic loading mechanism according to claim 1, characterized in that the slider automatic loading mechanism is comprised of an elastic member disposed on the support base so as to have the same effect as the slider automatic loading mechanism, and a means for transmitting the driving force of the driving section to the pressing member. . 3. As a means for transmitting the driving force of the loading means to the pressing member, a pin member is movably attached to the support base, and one end of the pin member is provided with a hook portion that engages with the shape memory alloy member and the elastic member, 2. The automatic slider loading mechanism according to claim 1, wherein the other end is provided with a hook portion that does not engage with the pressing member during loading but engages with the pressing member during unloading. 4. The loading means includes a support base rotatably supported by a guide bar and provided with a pressing member, a shape memory alloy member attached between the guide bar and the support base, and a recovery mechanism for the shape memory alloy member. The automatic slider loading mechanism according to claim 1, further comprising an elastic member disposed between the guide bar and the support base so as to have a spring force against the force. .