JP2682506B2 - Magnetic disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device capable of effectively preventing the occurrence of head crush due to an external impact.

[0002]

2. Description of the Related Art The structure of a conventional magnetic disk device will be described with reference to the drawings. First, FIG. 7 is a schematic view showing a normal write / read state.

Here, the magnetic disk device includes a disk-shaped magnetic disk 51, a magnetic head 52 arranged on the magnetic disk 51 for reading and writing data, and the magnetic head 5.
2 and sliders 57a and 57b carrying the magnetic head 5
A head drive unit 53 for positioning the magnetic head 2 at a predetermined position on the magnetic disk 51, and a housing 55 for holding components such as the head drive unit 53 are provided. In addition, the magnetic head 52 pushes the sliders 57a and 57b that generate a levitation pressure for floating above the rotating magnetic disk 51 and the sliders 57a and 57b against the magnetic disk 1 so that the sliders 57a and 57b do not lift too much. It is composed of a suspension 59 for applying pressure. The suspension 59 is formed by bending a plate material of a stainless alloy along the longitudinal direction, and the bent portion 59a produces a spring effect to press the sliders 57a and 57b against the magnetic disk 51.

When the magnetic disk device is operating and the magnetic disk 51 is rotating, the slider 57a,
57b is a balance between the pressure received from the rotating magnetic disk 51 and the pressure received from the suspension 59, which is 0.
It floats on the magnetic disk 51 while maintaining a minute flying distance of about 1 [μm]. When the magnetic disk device does not operate and the magnetic disk 51 is not rotating, the sliders 57a and 57b are positioned by the head drive unit 53 near the outer periphery of the magnetic disk 51 and come into contact with the magnetic disk 51. ing. At this time, a gap of about 2.0 [mm] is secured between the magnetic head 52 and the housing 55.

Next, the operation of the conventional magnetic disk device will be described with reference to the drawings. FIG. 8 is a schematic diagram showing the operation when the conventional magnetic disk device receives a constant impact from the outside. That is, in the magnetic disk device, as shown in FIG.
The impact force is applied from below to above.

According to this, when the magnetic disk device itself receives an impact from the outside due to a drop or the like, a constant acceleration is also applied to the sliders 57a and 57b (magnetic head 52). This acceleration is applied to the magnetic disk 51 among the sliders 57a and 57b that are in contact with the magnetic disk 51.
A moment M ₁ acting in the direction of separating from the magnetic disk 51 is generated on the slider 57b on the lower side of the. When the moment M ₁ is larger than the moment M ₂ that pushes the slider 57b against the magnetic disk 51 by the spring action of the suspension 59, the slider 57b separates from the magnetic disk 51. Further, the greater the impact acceleration acting, the more the suspension 59 bends, and the slider 57b
Moves away from the magnetic disk 51.

Then, the acceleration due to the shock is applied to the slider 57.
Immediately after no longer acting on b, the flexed suspension 59 tries to return to its original state by its own elastic force. As a result, the slider 57b is pushed back to the magnetic disk 51 and collides with the surface of the magnetic disk 51. Then, the larger the acceleration acting due to the impact caused by the drop or the like, the greater the deflection of the suspension 59, and the slider 57b and the magnetic head 52 are largely separated from the magnetic disk 51. Therefore, the impact force at the time of the collision with the magnetic disk 51 is reduced. growing. This is because as the suspension 59 bends more, the elastic energy of the suspension 59 for pushing the magnetic head 52 back to the magnetic disk 51 increases, and the speed of the magnetic head 52 and the slider 57b at the moment of collision with the magnetic disk increases. , Because the kinetic energy increases.

[0008]

However, in the above conventional example, the following inconveniences have occurred. That is, in the above-mentioned conventional example, when the magnetic disk device receives a large impact due to a drop or the like, the suspension is largely bent and the magnetic head is largely separated from the magnetic disk surface. Then, by the reaction, the magnetic head is pushed back to the magnetic disk surface, and collides with the magnetic disk surface with a large impact force,
There is a problem that the magnetic head and the magnetic disk are damaged.

For example, the impact force between the magnetic head and the surface of the magnetic disk caused by dropping is 200 [G].
If (G: gravitational acceleration) is exceeded, a collision dent of the magnetic head is generated on the surface of the magnetic disk, and the magnetic head is also damaged such as cracked or chipped. As a result, it becomes impossible to read and write data normally, resulting in irreparable and fatal injury called head crush.

[0010]

It is an object of the present invention to improve the disadvantages of the above conventional example, and in particular, even when a large impact force is applied to the magnetic disk device due to an operator's inadequacy, the magnetic head and the magnetic disk are prevented from being damaged. An object of the present invention is to provide a magnetic disk device that can be prevented.

[0011]

In order to achieve the above object, in the invention according to claim 1, a disk-shaped magnetic disk and a magnetic head for writing and reading magnetic signals facing the magnetic disk. A slider for carrying the magnetic head on one surface facing the magnetic disk, a head drive section for positioning the magnetic head at a predetermined position on the magnetic disk, and a housing for holding the head drive section. In the magnetic disk device, a stopper means is provided near the other surface of the slider and
The stopper means is integrally formed with the head drive section,
I take the means to say.

According to the second aspect of the invention, the stopper is provided.
The means is made of the same material as the head drive
The other configuration is the same as that of the invention of claim 1.
You.

According to the third aspect of the invention, the slider is
The gap between the other surface of the and the stopper means is approximately 1 mm.
The other configuration is defined in claim 1 or
This is the same as the invention described in 2.

[0014]

[0015]

[0016]

[0017]

According to the present invention, a disk-shaped magnetic disk, a magnetic head for writing and reading magnetic signals facing the magnetic disk, a slider for carrying the magnetic head on one surface, and the magnetic head are provided. In a magnetic disk device including a head drive unit that positions the magnetic disk at a predetermined position and a housing that holds the head drive unit, stopper means is provided near the other surface of the slider. At this time, first, it is assumed that the magnetic disk device has dropped onto the floor or the like due to, for example, an operator's inadequacy.
Then, a constant impact force is applied to the entire magnetic disk device.

When this impact force is applied, a moment acting in a direction separating from the magnetic disk is generated in the slider facing the magnetic disk and the magnetic head, and the slider below the magnetic disk. This moment is
When the moment of pressing the magnetic head toward the magnetic disk by the spring action of the suspension is larger than the moment, the magnetic head separates from the magnetic disk surface. Further, the greater the impact acceleration that acts, the more the suspension bends, and the magnetic head moves away from the magnetic disk surface.

At this time, since the other surface of the slider carrying the magnetic head comes into contact with the stopper means arranged in the vicinity thereof, the amount of flexure of the suspension is appropriately suppressed. As a result, the elastic energy stored by the flexure of the suspension is also small. Immediately after the acceleration due to the impact does not act on the slider, the flexed suspension tries to return to its original state due to its own elastic force. However, since the elastic energy is small, the impact when the magnetic head collides with the magnetic disk surface is also small. Therefore, even if a large impact force is applied to the magnetic disk device, damage to the magnetic disk and the magnetic head is effectively prevented.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. First, FIG. 1 is a view for explaining the principle of the present invention , showing an enlarged view of a magnetic head area of a magnetic disk device.
The magnetic disk device includes a disk-shaped magnetic disk 1, a magnetic head 2 that faces the magnetic disk 1 to write and read magnetic signals, and a slider 7a that carries the magnetic head on one surface facing the magnetic disk. , 7b,
The magnetic head 2 includes a head drive unit 3 for positioning the magnetic head 2 at a predetermined position on the magnetic disk 1, a housing 5 for holding the head drive unit 3, and sliders 7a and 7a.
Stoppers 4a and 4b are provided near the other surface of b.

Explaining these in more detail, the magnetic disk 1 is engaged with a drive motor (not shown) so as to be rotationally driven in a horizontal plane about a magnetic disk rotation shaft (not shown).

Sliders 7a and 7b are provided on both upper and lower surfaces of the magnetic disk 1 via a head drive section 3 and a suspension 9 which will be described later. These sliders 7a, 7b
Is arranged so as to carry a magnetic head 2 described later on one surface on the side facing the magnetic disk 1, and maintains a predetermined gap with the surface of the magnetic disk 1 during operation of the magnetic disk device. Is configured to.

Here, when the magnetic disk drive is operating, the sliders 7a and 7b balance the pressure received from the rotating magnetic disk 1 and the pressure received from the suspension 9, specifically, about 0.1 micron. Leaving on the magnetic disk 1 while maintaining such a minute flying distance. on the other hand,
In the non-operation, the magnetic disk 1 does not rotate and the magnetic head 2
Is positioned near the outer peripheral portion of the magnetic disk 1 by the head drive unit 3 and is in contact with the surface of the magnetic disk 1. Further, the sliders 7a and 7b are configured to be movable in the radial direction of the magnetic disk 1 according to the area where data is recorded when the head drive unit 3 reads and writes magnetic data.

The magnetic head 2 carried by the sliders 7a and 7b has a function of extracting the magnetic data recorded on the magnetic disk 1 as an electric signal.
When the magnetic disk device is in operation, it has a predetermined gap with the surface of the magnetic disk 1.

The suspension 9 extending from the head drive unit 3 and supporting the sliders 7a and 7b at the tip thereof is made of a stainless alloy plate material, and has a portion 9a bent along its longitudinal direction. I have it.
The bent portion 9a has the function of a spring, and the sliders 7a and 7b are pressed against the surface of the magnetic disk 1 with a predetermined pressing force.

Further, as shown in FIG. 1, stopper means 4a, 4b are provided in the vicinity of the other surface of the sliders 7a, 7b (the surface not facing the magnetic disk 1). The stopper means 4a, 4b are arranged in the vertical direction (vertical direction in the drawing) of the sliders 7a, 7b carrying the magnetic head 2.
The magnetic head 2 is installed near the outer periphery of the magnetic disk 1 on which the magnetic head 2 is positioned when the magnetic disk device is not operating. Also, the slider 7
The gap between the other surface of a and 7b and the stopper means 4a and 4b is set to about 1 [mm] so that the stopper means 4 is formed.
The a and 4 b are fixed to the inner wall of the housing 5.

Here, the stopper means 4a, 4b may be provided with a rubber material at the portions contacting the sliders 7a, 7b. This is because the impact can be mitigated so as not to damage the magnetic head 2 when the magnetic head 2 collides with the stopper means 4a, 4b. Also,
The stopper means may be made of a plastic material, and polon or the like is suitable. On the other hand, although the shock absorbing function is small, the stopper means may be made of stainless steel or aluminum alloy. This is because these alloys can adjust the gap between the magnetic head 2 and the stopper means 4a and 4b with high accuracy and at a low cost, as compared with rubber / plastic materials.

However, the material of the stopper means 4a, 4b is
The material is not particularly limited to the above-mentioned materials as long as it has a characteristic that gas and dust are unlikely to be generated. This is because the stopper means 4a and 4b having such characteristics prevent the generation of gas and dust inside the magnetic disk device and prevent the failure of the magnetic disk device. Further, as shown in FIG. 5, if the stopper means 14a and 14b are made of an aluminum alloy, they may be integrated with the housing 15. Furthermore, as shown in FIG.
The a and 24b may be integrated with the head drive unit 23. In this case, the sliders 27a and 27b are
Even if the slider 27a, 27b and the stopper means 24a, 24b do not move relative to each other even when the magnetic head 2 is moved, the stopper means 24a is suitable for a wide range of movement of the magnetic head 2 with a simple structure. , 24b.

Next, the operation and function of the magnetic disk device disclosed in FIG. 1 will be described with reference to FIG. 2. FIG. 2 shows that the magnetic disk device disclosed in FIG. FIG. 6 is a diagram showing a state of a slider 7b and a suspension 9 when is biased. In particular, FIG. 2 shows a case where an impact force is applied from below the magnetic disk device.

First, when the magnetic disk device receives a large impact such as a drop, the same acceleration is applied to the sliders 7a and 7b facing the magnetic disk device. Therefore, a moment M ₁ acting in the direction of separating the slider 7b from the magnetic disk 1 is generated by the acceleration generated by the impact on the slider 7b arranged on the lower surface of the magnetic disk 1 in FIG. Therefore, the moment M ₁ obtained by the following equation (1) is reduced by the spring effect of the suspension 9 obtained by the equation (2).
Is larger than the moment M ₂ pressing the bottom surface of the magnetic disk (M ₁ > M ₂ ), the slider 7 b moves away from the surface of the magnetic disk 1. Further, letting M ₃ be the moment for separating the slider 7b from the lower surface of the magnetic disk 1 by a distance of X [m], the following relationship is derived.

M ₁ = 9.8 × a × α {(m ₁ × L ₁ ) + (m ₂ × L ₂ )} (1) M ₂ = 0.0098 × W × L ₁ ………………………………………… (2)

Here, each symbol indicates the following values.

M ₁ Moment [N / m] acting in the direction of separating the slider 7 b from the magnetic disk 1 by impact [N / m] M ₂ Moment [N / m] for pressing the slider against the surface of the magnetic disk 1 by the spring action of the suspension 9.
m] W ... Spring load of suspension 9 [gf] a ... Acceleration due to impact acting on magnetic disk device [G] α ... Transmission coefficient of acceleration m ₁ ... Mass of slider [kg] m ₂ ... Mass of suspension 9 [kg ] L ₁ ... Distance from rotation center of magnetic head 2 to center of gravity of slider 7b [m] L ₂ ... Distance from rotation center of magnetic head 2 to center of gravity of suspension 9 [m]

Further, the apparent moment that the slider 7b acts to separate from the lower surface of the magnetic disk 1 is M
_If these relationships are expressed using M ₁ and M ₂ described above as 3, the formula (3) is obtained.

M ₃ = M ₁ −M ₂ …………………………………………………… (3)

When the slider 7b is separated from the lower surface of the magnetic disk 1 by the moment M ₃ , the distance between the sliders 7b is X, and the relationship between the moment M ₃ and the distance X is expressed by equation (4) and equation (4). It becomes like 5).

M ₃ = k × X × L ₁ ……………………………………………………… (4) X = M ₃ ÷ (k × L ₁ ) ……… …………………………………………… (5)

Here, k represents the spring constant of the suspension 9.

In the above equations (1) to (2), W = 5
α = 1.5, m ₁ = 6.4 × 10 ⁻⁶ , m ₂ = 40 × 10
^-6 , L ₁ = 15.21 × 10 ^-3 , L ₂ = 6.15 × 10
^-3 , k = 18 is substituted, and M ₃ is calculated based on these calculated results. Then, the value of M ₃ is substituted into the equation (5) to calculate the separation distance X.

Here, FIG. 3 shows the relationship between the impact acceleration a biased by the magnetic disk device and the separation distance X. According to FIG. 3, the acceleration a acting on the magnetic disk device
Is larger, the amount of bending of the suspension 9 is larger, the slider 7b is separated from the lower surface of the magnetic disk 1, and the separation distance X is also larger. For example, the separation distance X becomes about 1 [mm] when the acceleration is 200 [G], and
If you do not take any measures when the acceleration is 250 [G],
It reaches about 1.9 [mm].

Further, FIG. 4 shows the separation distance X and the slider 7b.
FIG. 3 is a diagram showing a relationship between a magnetic head 2 and a damaged state. According to FIG. 4, it was found that the slider 7b, the magnetic head 2 and the magnetic disk 1 were not damaged if the separation distance X was 1 [mm] or less. On the other hand, the separation distance X is 1
When it exceeds [mm], the magnetic disk 1 begins to be damaged such as a dent, and when the distance X becomes about 2 [mm],
The magnetic head 2 also begins to receive damage such as cracks and chips.

Based on these results, in this embodiment,
The movable range of the magnetic head 2 (slider 7b) is about 1 [m
m] or less, the stopper means 4b is fixed to the wall surface of the housing. That is, about 1 [mm] from the other surface of the slider 7b that does not contact the magnetic disk 1
The stopper means 4b is arranged with a space of.
Therefore, the slider 7b will not collide with the stopper means 4b and the suspension 9 will not bend even if the slider 7b is accelerated by a large impact.

Subsequently, the acceleration due to the shock is applied to the slider 7b.
Immediately after the suspension 9 stops working, the flexed suspension 9 tries to return to its original state.
Then, the slider 7b is pushed back to the lower surface of the magnetic disk 1 and comes into contact with the lower surface of the magnetic disk 1. However, in this embodiment, since the separation distance X does not exceed 1 [mm], damage to the magnetic head 2 and the magnetic disk 1 caused by collision is significantly reduced as compared with the conventional case.

[0044]

Since the present invention is constructed and functions as described above, by providing the housing means of the magnetic disk device with the stopper means, it is possible to suppress the amount of flexure of the suspension even when a large impact is caused by a drop or the like. The vertical movable range of the magnetic head, that is, the maximum deflection amount can be set to an appropriate value. The impact force generated between the magnetic head and the magnetic disk due to the bending amount of this suspension is 200
[G] or less. Therefore, even if the magnetic head is pushed back to the magnetic disk surface by the restoring force of the bent suspension and collides with the magnetic disk surface, the magnetic head and the magnetic disk are not damaged. As a result, there is an excellent effect that the magnetic data can be normally read and written even when the magnetic disk device receives a large shock due to a drop or the like.

Further, since the stopper means is integrally formed with the head drive portion or the housing, in this case, the relative position of the slider and the stopper means does not change, so that the magnetic head can be moved in a wide range with a simple structure. Also, it can properly serve as a stopper means. Further, in manufacturing the magnetic disk device, it is possible to suppress the number of parts, and as a result, it is possible to reduce the manufacturing cost, which is an excellent effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating the principle of the present invention.

FIG. 2 is a cross-sectional view showing a state when an impact force is applied to the magnetic disk device disclosed in FIG.

FIG. 3 is a diagram showing a relationship between a distance X at which a magnetic head of a magnetic disk device according to an embodiment of the present invention is separated from a magnetic disk surface and an acceleration a acting on the magnetic head.

FIG. 4 is a diagram showing the relationship between the damage to the magnetic head and the magnetic disk of the magnetic disk device of one embodiment of the present invention and the distance X at which the magnetic head is separated from the magnetic disk surface.

5 is a schematic diagram of a modified example of the magnetic disk device disclosed in FIG. 1. FIG.

FIG. 6 is a schematic view of a magnetic disk device according to a first embodiment of the invention.

FIG. 7 is a schematic diagram of a conventional magnetic disk device.

FIG. 8 is a cross-sectional view showing a state in which an impact is applied to a conventional magnetic disk device.

[Explanation of symbols]

 1, 11, 21 Magnetic disk 2, 12, 22 Magnetic head 3, 13, 23 Head drive unit 4a, 14a, 24a Stopper means 4b, 14b, 24b Stopper means 5, 15, 25 Housing 7a, 17a, 27a Slider 7b, 17b, 27b slider 9, 19, 29 suspension

Claims (3)

(57) [Claims] 1. A disk-shaped magnetic disk, a magnetic head for writing and reading a magnetic signal facing the magnetic disk, a slider for carrying the magnetic head on one surface facing the magnetic disk, and A magnetic disk device comprising a head drive section for positioning a magnetic head at a predetermined position on the magnetic disk and a housing for holding the head drive section, wherein a stopper means is provided near the other surface of the slider.
In addition, the stopper means is integrated with the head drive section.
A magnetic disk device having the above-mentioned configuration . 2. The stopper means and the head drive section
The magnet according to claim 1, wherein the magnets are made of the same material.
Qi disk device. 3. The other surface of the slider and the stopper
It is characterized in that the gap with the means is set to about 1 mm.
The magnetic disk device according to claim 1 or 2.