JPH0773613A - Magnetic disk unit - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a magnetic disk device capable of achieving both thinning of the device and high seek performance. [Structure] The coil 13 is formed on the bottom wall portion of the housing 2 facing the coil 13 constituting the voice coil motor 12.
Through hole 17 is formed over the swing range of
The magnet yoke 16 of the voice coil motor 12 is arranged so as to fill the through hole 17 in the housing 2, and the magnet 15 held by the magnet yoke 16 is attached to the housing 2
Housed inside. As a result, the bottom wall portion of the housing 2 which has not been used up to now is utilized as a space for attaching the magnet 15, and the magnet 15 having a large thickness corresponding to the entire thickness of the wall portion of the housing 2 is used.
Was used for the voice coil motor 12, the thickness of the magnetic disk device was reduced, and the seek time of the magnetic disk device was shortened.

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 for recording / reproducing information on / from a magnetic disk.

[0002]

2. Description of the Related Art In a magnetic disk drive using a magnetic disk, the magnetic head moves relative to the recording surface of the magnetic disk to record data on a track set on the recording surface.

For moving the magnetic head, a carriage is used to swingably support a magnetic head assembly incorporating the magnetic head, and the magnetic head assembly is swingably driven by a voice coil motor. Is being done.

Conventionally, such a voice coil mode has been used.
The coil is composed of a coil, a magnet provided on both sides of the coil, and a magnet yoke.
The whole is housed together with the magnetic disk in a protective case (consisting of a housing and a top plate that closes an opening of the housing).

More specifically, as shown in FIGS. 15 and 16, the voice coil motor a is installed in parallel with the bottom wall of the housing d of the protective case c together with the installation of the carriage b. It has a coil e, and a fan plate-shaped first magnet yoke h is provided on the side of the top plate f sandwiching the coil e.
Is mounted on the inner surface of the bottom wall of the housing d on the opposite side to the fan-shaped magnet i held by the fan-shaped second magnet yoke h, and the yoke is bossed. Part j
It is configured to be screwed through. This allows
In the voice coil motor a, when a current is applied to the coil e, a thrust force for rotating the carriage b is generated. Incidentally, k indicates a magnetic disk installed in the housing d, and m indicates a suspension holding a magnetic head (not shown).

[0006]

The magnetic disk drive is
One of the main performances is expressed by a term called "seek time". This shows the movement time required when the magnetic head moves to the target track of the magnetic disk. In the magnetic disk device, the shorter this seek time is,
It can be said that it has excellent performance.

To reduce the seek time, the driving thrust generated from the voice coil motor a is increased. That is, in order to improve the seek performance, the voice coil motor a may be increased by using the magnet i having a large thickness t.

Here, there is a strong demand for the magnetic disk device to be thin due to downsizing of equipment incorporating the magnetic disk device, and not only the above-mentioned seek performance but also the height of the device, that is, It is also required to keep the thickness dimension T low.

However, since the magnetic disk device has a structure in which all the components constituting the voice coil motor a are accommodated in the protective case c, when the magnet i becomes thick, it is affected. The thickness T of the magnetic disk device
Limited protection case c
There was a limit in improving seek performance.

On the other hand, in the magnetic disk device disclosed in Japanese Patent Laid-Open No. 4-78072, a recess is formed in the bottom wall portion of the housing facing the coil, and a magnet yoke holding a magnet is provided in the recess. A magnetic disk device housed therein has been proposed.

According to this, in such an outside arrangement of the magnet, if the bottom wall portion of the recess is thinned, a thick magnet can be used for the voice coil motor a, but the bottom wall portion of the recess is a coil. Since it is interposed between the magnet and the magnet, the bottom wall portion of the magnet becomes an obstacle and cannot be made large enough to bring about a remarkable effect.

That is, as the magnet i becomes thicker, the thickness T of the magnetic disk device also becomes thicker.
For this reason, it is still difficult to improve the seek performance within the limited protection case c.

The present invention has been made in view of the above circumstances, and its purpose is to provide a magnetic disk capable of achieving both thinning of the apparatus and high seek performance. To provide a device.

[0014]

In order to achieve the above object, a magnetic disk drive according to a first aspect of the present invention is a wall portion on one side of a main body case which faces a coil constituting a voice coil motor. A through hole is formed over the swing range of the coil, and a second magnet yoke constituting a voice coil motor is arranged so as to fill the through hole. The magnet held by the magnet yoke is housed in the main case.

In the magnetic disk drive according to a second aspect of the present invention, in addition to the first aspect, a seal for sealing the gap between the through hole exposed to the outside and the second magnet yoke. It is in the provision of a ruler member.

According to a third aspect of the present invention, there is provided a magnetic disk device, wherein a wall portion on both sides of a main body case facing a coil constituting a voice coil motor is provided over the swing range of the coil.
A first magnet yoke forming a voice coil motor is arranged so as to form a first through hole and a second through hole and to fill the first through hole. A second magnet yoke constituting a voice coil motor is provided in the second through hole so as to fill the through hole.
This is because the magnet held by the magnet was housed in the case of the main body.

According to a fourth aspect of the magnetic disk drive of the present invention, in addition to the third aspect, the first through hole has an opening larger than the swing range of the coil, and the coil swings at the opening edge. And forming a receiving portion that is disposed between the first and second magnet yokes and receives the edge portion of the first magnetic yoke.

According to a fifth aspect of the magnetic disk drive of the present invention, in addition to the third aspect, each first through hole exposed to the outside,
A seal member is provided to seal a gap between the second through hole, the first magnet yoke and the second magnet yoke.

[0019]

According to the magnetic disk drive of claim 1,
The entire thickness of the wall on one side of the body case, which has not been used up to now, is utilized as a space for attaching the magnet.

This makes it possible to use, in the voice coil motor, a magnet which provides a large thrust by the thickness of the wall portion of the main body case, that is, a magnet having a large thickness dimension.

As a result, the seek time can be shortened while the thickness of the magnetic disk device is kept low. According to the magnetic disk drive of the second aspect, in addition to the above, through the gap between the through hole and the second magnet yoke,
Dust is prevented from entering the inside of the device.

According to the magnetic disk drive of the third aspect, the entire thickness of the wall portions on both sides of the main body case, which has not been used up to now, can be utilized as a space for attaching the magnet. It will be possible.

This makes it possible to use a magnet for producing a large thrust force corresponding to the thickness of the wall portion of the main body case to be utilized, that is, a magnet having a large thickness dimension for the voice coil motor.

As a result, as in the first aspect, the seek time can be shortened while suppressing the thickness of the magnetic disk device to be low. According to the magnetic disk drive of the fourth aspect, in addition to the third aspect, the receiving portion for receiving the first magnet yoke and the coil do not overlap each other, and the first magnet yoke is correspondingly provided. Close to the coil.

That is, the first magnet yoke can be brought as close to the coil as possible with respect to the coil, and the thickness dimension of the magnetic disk device can be further reduced and the magnet can be made larger accordingly. It will be possible.

According to the magnetic disk drive of the fifth aspect, in addition to the third aspect, the first through hole, the second through hole, the first magnet yoke and the second magnet yoke are provided. Dust is prevented from entering the inside of the device through the gap.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention shown in FIGS.
A description will be given based on the embodiment. FIG. 1 shows an overall exploded view of a magnetic disk device using, for example, a magnetic disk to which the present invention is applied, in which reference numeral 1 is a protective case (corresponding to a main body case).

The protective case 1 comprises a housing 2 whose upper surface is open and a top cover 3 which closes the opening of the housing 2. The housing 2 and the top cover-3 are fixed by a fixing screw 1a.

On the left side of the housing 2 which is closed by the top cover-3, for example, 2 as shown in FIGS. 2 and 3.
A plurality of magnetic disks 4 are housed so as to overlap with each other at a predetermined interval in the vertical direction. These magnetic disks 4, 4
Is directly connected to a hub 5 of a spindle motor (not shown) mounted on the housing 2. That is, the magnetic disks 4, 4 are rotated at high speed by the spindle motor.

On the right side of the housing 3, a rotary carriage assembly 6 is housed as shown in FIG. The carriage assembly 6 includes a housing 2
It has a rotatable carriage 7 which is rotatably supported. As shown in FIG. 3, on the front end side of the carriage 7, there are four arms 9 ... 9
(Only shown clearly). A magnetic head assembly 10 is connected to each tip of each of these arms 9.

The magnetic head assembly 10 comprises a suspension 11 in the form of a strip plate, and a magnetic head (neither of which is shown) supported on the tip of the suspension 11 via a gimbal. This magnetic head assembly 10 includes a suspension 11
Mount the mount (not shown) formed on the rear end of the arm 9
The carriage 7 is mounted on the carriage 7 by connecting to the carriage 7.

Reference numeral 10a is a control board connected to each magnetic head through a flat cable 10b.
On the other hand, a voice coil motor 12 for swinging the carriage 7 is accommodated on the right side of the housing 2.

Here, this voice coil motor 12
In the following, 13 is a coil wound in a fan shape. The coil 13 is supported between two support rods 7a, 7a protruding rearward from the rear end of the carriage 7. The coil 13 is held in parallel with the bottom wall 2a of the housing 2 by being supported by the support rods 7a, 7a. That is, the coil 13 is swingably displaced about the rotation fulcrum of the carriage 7.

As shown in FIGS. 3 and 4, a magnet yoke is provided on the side of the top cover-3 which sandwiches the coil 13.
A magnet 14 (first magnet yoke) is arranged close to the coil 13. The magnet yoke 14 extends in a fan shape along the swing range of the coil 13.

A magnet yoke 16 (second magnet yoke) holding a magnet 15 is disposed on the bottom wall 2a side of the housing 2 with the coil 13 sandwiched therebetween. The magnet 15 and the magnet yoke 16
Also extends in a fan shape, following the swing range of the coil 13.

In addition, each pair of magnet yokes 14,
16 has a fan shape slightly larger than the magnet 15. The magnet 15 has a mounting structure designed to save space, and is installed on the bottom wall 2 a of the housing 2.

That is, as shown in FIGS. 1 to 3, the bottom wall 2a of the housing 2 facing the coil 13 is provided with a through hole 17 over the swing range of the coil 13. As shown in FIGS. 2 to 4, the through hole 17 has a fan-shaped opening 17a corresponding to the outer shape of the magnet yoke 16 formed on the outer side, and a fan-shaped opening having a slightly smaller outer shape than the opening 17a formed on the inner side. In combination with the opening 17b. Reference numeral 17c is a step formed at the boundary between the opening 17a and the opening 17b to serve as a yoke support seat.

The magnet yoke is inserted into the opening 17a from the outside of the housing 2 so as to fill the opening 17a.
The plug 16 is inserted. And this magnet yoke 1
6 is fixed to the housing 2 by, for example, small screws (not shown) screwed from the peripheral edge of the yoke toward each part of the step 17c.

The tip of the magnet 15 has an opening 17
It projects to the inside of the housing 2 through a and 17b and is close to the coil 13. Due to the structure of penetrating the bottom wall 2a, the bottom wall 2a is utilized as a part of the mounting space, and the magnet 15 and the magnet yoke 1
6 is housed in the housing 2.

The magnet yoke 16 and the coil 1
The magnet yoke 14 above 3 is a magnet yoke.
Screws 19 and 1 that are screwed from both ends of the magnet 14 toward bosses 18 projecting from both ends of the magnet yoke 16.
It is concluded by 9. As a result, the magnet yoke 14 and the magnet 15 are arranged on both sides of the coil 13 with the narrowest gap therebetween.

The voice coil mode thus constructed
The entire cover 12 is housed in the protective case 1 by attaching the top cover 3 to the housing 2. Then, the thrust generated by the voice coil motor 12 causes the magnetic head to swing between the innermost circumference and the outermost circumference of the magnetic disk 4, so that data is recorded on the recording surface of the magnetic disk 4. The data can be recorded and the recorded data can be reproduced.

A sheet-shaped seal 20 (seal member) is attached to the lower surface of the magnet yoke 16 exposed on the outer surface of the housing 2 and the outer surface portion of the housing 2 around the yoke. A gap 21 is sealed between the edge of the opening 17a attached to the outside and the peripheral edge of the magnet yoke 16.

When installing the voice coil motor 12 in such a magnetic disk device, the magnet 15 is first attached to the housing 2 in which the magnetic disk 4 has been assembled.

This is a through hole 17 from the bottom of the housing 2.
To the magnet yoke 1 with the magnet 15 side first.
6 is inserted. As a result, as shown in FIG. 2, the opening 17a of the through hole 17 is filled with the magnet yoke 16, and the tip of the magnet 15 and the boss portion 18 penetrate the opening 17b and project into the housing 2. Go.

Then, using a small screw, this magnet yo
The hook 16 is fixed on the step 17c. After that, the carriage 7 having the magnetic head assembly 6 and the coil 13 is rotatably supported by the housing 2. At this time, the magnetic head assembly 6 is placed beside the magnetic disk 4. Further, the substrate 10a is fixed in the housing 2.

Next, the magnet yoke 14 is mounted on the boss end protruding into the housing 2, and screws 19, 19 are screwed from the end of the magnet yoke 14 to the boss portion 18,
The magnet yoke 14 is screwed into the housing 18 to fix it, and the seal 2 is attached to the bottom surface of the magnet yoke 14 exposed on the bottom surface of the housing 2 and the peripheral bottom surface portion.
0 is attached, and the gap 2 around the magnet yoke 14
Seal 1

Then, using a jig (not shown), each magnetic head assembly 6 placed on the side of the magnetic disk 4 is moved to the magnetic disk 4 side, and each magnetic head is moved to the front and back of each magnetic disk 4. Place it on the recording surface. Then, the coil 13 closely faces the magnetized surface of the magnet 15 and the lower surface of the magnet yoke 14.

This completes the assembly of the voice coil motor 12 as shown in FIG. Then, the top cover-3 is screwed to the housing 2 to close the opening of the housing 2 with the top cover-3.

As a result, in the closed protective case 1,
Magnetic disk 4, carriage assembly 6, voice
A magnetic disk device, which houses devices such as a coil and motor 12, is assembled.

Looking at the magnet 15 of the voice coil motor 12 built in such a magnetic disk device,
As shown in the cross-sectional view of FIG. 4, it can be seen that the entire thickness of the bottom wall 2a of the housing 2, which has not been used up to now, is utilized as a mounting space to be mounted on the housing 2.

This means that the magnet 15 that provides a large thrust force, that is, the thickness t of the bottom wall 2 of the housing 2, that is, the thickness t is increased by the thickness H, as compared with the conventional magnets. The magnet 15 can be used for the voice coil motor 12.

As a result, the seek time, which is one of the main performances of the magnetic disk device, can be shortened while keeping the thickness T of the magnetic disk device low. Therefore, with the structure in which the magnet 15 is attached through the bottom wall 2a of the housing 2, it is possible to sufficiently improve both the thinning of the magnetic disk device and the high seek performance, and a high-performance magnetic disk. A disk device can be realized.

Moreover, the magnet yoke 1 with the seal 20.
By sealing the gap 21 existing in the peripheral portion of 6, the dust and the like do not enter the inside of the magnetic disk device having high precision through the gap 21.

5 to 8 show a second embodiment of the present invention. This embodiment is a modification of the first embodiment, and is a sheath.
Instead of a sheet-like sheet, a filler 23 made of a resin material or the like is used to seal the gap 21.

That is, in this embodiment, the filling 23 is filled in the entire area of the gap 21 so that dust and the like do not enter the inside of the magnetic disk device through the gap 21.

9 to 11 show a third embodiment of the present invention. In this embodiment, not only the magnet 25 but also
The magnet yoke 14 also employs a structure in which the wall portion is mounted and utilized.

That is, the top cover-3 has a through hole 17
Similarly to the above, the through hole 25 is provided over the swinging range of the coil 13, and the other magnet yoke 14 is fitted in the through hole 25.

More specifically, the peripheral portion of the through hole 25 is recessed. As a result, a vertical wall 25a directed downward is formed at the peripheral edge of the through hole 25, and a horizontal wall 25b is formed at the lower end of the vertical wall 25a so as to continuously project inward from the same end.

As a result, a fan-shaped opening 26a corresponding to the outer shape of the magnet yoke 14 is formed in the outer portion of the through hole 25, and a fan-shaped opening 26b having a slightly smaller outer shape than the opening 26a is also formed in the inner portion. is doing. Of course,
A horizontal wall 25b which is a boundary between the opening 26a and the opening 26b serves as a yoke support seat (reception portion).

Then, the top cover-3 is provided in the opening 26a.
The magnet yoke 14 is inserted from the surface (outside) of the above so as to fill the opening 26a. The magnet yoke 14 is fixed by a fixing means such as an adhesive or a screw (not shown), and the magnet yoke 14 is held in a state of protruding from the top cover-3 to the back surface.

As a result, when the top cover 3 is attached to the housing 2, the magnet yoke portion exposed from the opening 26a comes close to the coil 13. In addition, the top surface of the magnet yoke 14 exposed from the surface of the top cover-3 and the top cover-3 around it.
A seal 28 is affixed to the surface portion of the above, and a gap 29 between the magnet yoke 14 and the opening 26a is sealed.

The magnet cover is attached to the top cover-3.
If the structure for mounting the cable 14 is used, the magnet yo
The distance from the top cover-3 required to mount the brake 14 to the magnet yoke 14 is shortened.

This means that the magnet 15 is attached to the thickness of the thick part of the top cover 3 which has not been used up to now, and also in the gap between the top cover 3 and the magnet yoke 14. Can be used as a space for

As a result, it is possible to provide a high-performance magnetic disk device which is further thinned and has higher seek performance than the first embodiment. Needless to say, since the seal 28 seals the gap 29 in the peripheral portion of the magnet yoke 14, dust and the like will not enter the inside of the highly accurate magnetic disk device through the gap 29. .

Moreover, as shown in FIG.
The opening 26b having an opening area larger than the swing range of No. 3 is used, and the horizontal wall 25b is connected to the opening 26b and the coil 1.
The horizontal wall 25b for receiving the magnet yoke 14 and the coil 13 are adopted by adopting the structure arranged between the swing range of No. 3 and the swing range of No.
Since it does not need to be overlapped, the magnet yoke 14 can be brought closer to the coil 13 accordingly.

That is, the magnet yo
The disk 14 can be brought as close as possible, and the thickness dimension of the magnetic disk device can be further reduced by that much, and
The magnet 15 can be enlarged.

12 to 14 show a fourth embodiment of the present invention. This embodiment is a modification of the third embodiment,
Instead of a sheet-like sheet, a gap 23 is sealed by using a filler 23 made of a resin material or the like.

That is, in this embodiment, the filler 23 is filled in the entire space of the gap 29 so that dust or the like does not enter the inside of the magnetic disk device through the gap 29. In the second to fourth embodiments, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

[0069]

As described above, claim 1 and claim 3
According to the invention described in (1),
The entire thickness of the wall portion of the voice coil can be used as a space for attaching the magnet of the voice coil motor, so a magnet that provides a large thrust by the thickness of the wall portion is used as the voice coil.・ Can be used for motors.

Therefore, the seek time can be shortened while suppressing the thickness of the device to a low level, and the magnetic disk device can be made sufficiently thin and high-sealed. Can be provided.

According to the second and fifth aspects of the present invention, in addition to the effects of the first and third aspects, dust and the like enter the inside of the apparatus through the gap at the peripheral edge of the magnet yoke. It is possible to prevent intrusion. According to the invention described in claim 4, the effects of claims 1 and 3 can be further enhanced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view for explaining an overall configuration of a magnetic disk device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a housing to which a magnet of the voice coil motor of the embodiment is attached.

FIG. 3 is a perspective view showing a housing to which the voice coil motor of the embodiment is attached.

FIG. 4 is a diagram showing voices housed in the protective case of the embodiment.
FIG. 3 is a sectional view of a magnetic disk device showing a coil motor.

FIG. 5 is an exploded perspective view for explaining an overall configuration of a magnetic disk device according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a housing to which a magnet of the voice coil motor of the embodiment is attached.

FIG. 7 is a perspective view showing a housing to which the voice coil motor of the embodiment is attached.

FIG. 8: Voices housed in the protective case of the embodiment
FIG. 3 is a sectional view of a magnetic disk device showing a coil motor.

FIG. 9 is an exploded perspective view for explaining the overall configuration of a magnetic disk device according to a third embodiment of the present invention.

FIG. 10 is a partially cutaway perspective view of the magnetic disk device showing the top cover to which the magnet yoke of the embodiment is attached.

FIG. 11 is a cross-sectional view of the magnetic disk device showing the voice coil motor housed in the protective case of the embodiment.

FIG. 12 is an exploded perspective view for explaining the overall configuration of a magnetic disk device according to a fourth embodiment of the present invention.

FIG. 13 is a partially cutaway perspective view of the magnetic disk device showing the top cover to which the magnet yoke of the embodiment is attached.

FIG. 14 is a cross-sectional view of the magnetic disk device showing the voice coil motor housed in the protective case of the embodiment.

FIG. 15 is an exploded perspective view showing a voice coil motor used in a conventional magnetic disk device together with the structure of the magnetic disk device.

FIG. 16 is a voice coil mode of the magnetic disk device.
FIG. 3 is a cross-sectional view of the magnetic disk device showing the configuration of the data.

[Explanation of symbols]

1 ... Protective case (main body case) 2 ... Housing 3 ... Top cover 4 ... Magnetic disk 7 ... Carriage 9 ... Arm 12 ... Voice coil motor 13 ... Coil 14 ... (first) Magnet yoke 15 ... Magnet 16 ... (second) Magnet yoke 17 ... Through hole 17a ... Opening (first through hole) 17b ... Opening (second)
Through hole) 20 ... Seal (sealing member) 21 ... Gap 23 ... Filling material (sealing member) 28 ... Seal (sealing member)
29) Gap

Claims (5)

[Claims] 1. A coil attached to a carriage is provided in a main body case, and a plate-shaped first coil is provided on one side sandwiching the coil.
, And a plate-shaped magnet held by a second magnet yoke on the other side to constitute a voice coil motor for swinging and driving the carriage. In the magnetic disk device, the main body case has a through hole formed in a wall portion facing the other side of the coil over the swing range of the coil, and the through hole is formed in the through hole. The magnetic disk device characterized in that the second magnet yoke is arranged so as to fill the space, and the magnet is housed in the main body case. 2. A seal member for sealing the same portion is provided in a gap between the through hole exposed to the outside and the second magnet yoke. 1. The magnetic disk device according to 1. 3. A coil attached to a carriage is arranged in a main body case, and a plate-shaped first coil is provided on one side sandwiching the coil.
, And a plate-shaped magnet held by a second magnet yoke on the other side to constitute a voice coil motor for swinging and driving the carriage. In the magnetic disk device according to the present invention, the main body case has a first through hole and a second through hole on the respective wall portions facing the one side and the other side of the coil over the swing range of the coil. A through hole is formed, the first magnet yoke is disposed in the first through hole so as to fill the same hole, and the first through hole is formed in the second through hole. A magnetic disk drive comprising a second magnet yoke and the magnet housed in the main body case. 4. The first through hole has an opening larger than the swing range of the coil, and is arranged at the opening edge between the swing range of the coil and the first magnet yoke. 4. The magnetic disk drive according to claim 3, wherein a receiving portion is formed to receive the edge portion of the magnetic disk. 5. The clearance between the first through hole and the second through hole exposed to the outside and the first magnet yoke and the second magnet yoke is sealed at the same portion. The magnetic disk drive according to claim 4, further comprising a seal member for controlling the magnetic field.