Recording device, cover, and method for manufacturing cover

Abstract

To provide a recording device capable of more surely suppressing slippage between fastening sections of a cover and a housing base.SOLUTION: A recording device includes: a fixing face 31 for fastening a housing base 17; a fastening section 33 that is part of a cover 19 fastened to the fixing face 31; a receiving face 27 on a front face and a contact face 29 of a back face in a thickness direction of the fastening section 33; a fastener 21 having a fastening face 21b abutting on the receiving face 27; and a rough face 29a provided on the contact face 29 and having hardness set by heat treatment.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a recording device such as a hard disk drive that accommodates a recording medium in a housing in which an opening of a housing base is closed by a cover, a cover used therefor, and a method for manufacturing the cover. [Background technology]

[0002] A conventional recording device is a magnetic disk device described in Patent Document 1.

[0003] In this magnetic disk drive, the cover is fastened to the spindle shaft of the housing base by contacting it, and the contact surface of the cover with the spindle shaft is roughened.

[0004] Therefore, when an external impact is applied, the surface roughening prevents the spindle shaft from slipping against the cover, making it possible to prevent the spindle shaft from tilting.

[0005] However, there are limits to how much slippage can be suppressed by simple surface roughening alone.

[0006] Such problems regarding the prevention of slippage can occur not only in the spindle shaft but also in the fastening portions between the carriage supporting the head and other covers and the housing base, which affect the impact resistance of the recording device. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-172671 Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved is that there is a limit to how much slippage can be prevented between the fastening portions of the cover and the housing base. [Means for solving the problem]

[0009] The present invention provides a recording device that stores a recording medium inside a housing in which the opening of the housing base is closed by a cover, the recording device comprising: a fastening fixing surface provided on the housing base; a fastening portion provided on the cover and fastened to the fixing surface; a receiving surface on the front surface in the thickness direction of the fastening portion; a contact surface on the back surface in the thickness direction of the mounting portion that abuts against the fixing surface; a fastener having a fastening surface abutting against the receiving surface in the thickness direction; and a rough surface provided on at least one of the contact surface, the fixing surface, and the receiving surface, the rough surface having a hardness set by heat treatment.

[0010] The present invention also provides a cover for closing an opening of a housing base and storing a recording medium inside the housing, the cover having a main body and a fastening portion for fastening, the fastening portion having a rough surface on at least one of the front and back surfaces having a hardness set by heat treatment.

[0011] The present invention also provides a method for manufacturing the above-mentioned cover, which comprises roughening the cover to form a rough portion on at least the front or back surface of the cover that is rougher than an unprocessed portion of the cover, and then heat-treating at least the rough portion to obtain the rough surface with a set hardness. [Effects of the Invention]

[0012] The present invention can more reliably prevent slippage between the fastening portions of the cover and the housing base. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a rear view of a cover used in a magnetic disk drive according to a first embodiment of the present invention. [Figure 2]FIG. 2 is a schematic cross-sectional view of the magnetic disk drive taken along line II-II of the cover in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view showing the fastening portion of the cover of FIG. 2 together with the disk. [Figure 4] FIG. 4 is a schematic cross-sectional view showing the relationship between the hub, spindle shaft, and spindle motor of FIG. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a fastening portion of the cover of FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a fastening portion of a cover according to a modified example of the first embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a fastening portion of a cover according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a fastening portion of a cover according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] The goal of more reliably suppressing slippage between the fastening parts of the cover and housing base is achieved by using a roughened surface whose hardness is set by heat treatment.

[0015] That is, the recording device 1 accommodates a recording medium 5 in a housing 3 in which the opening of a housing base 17 is closed by a cover 19. The recording device 1 includes a fixing surface 31, a fastening portion 33, a receiving surface 27, a contact surface 29, a fastener 21, and rough surfaces 27a, 29a, and 31a.

[0016] The fixing surface 31 is a fastening surface provided on the housing base 17. The fastening portion 33 is a surface provided on the cover 19 and fastened to the fixing surface 31. The receiving surface 27 is a surface provided on the front surface of the fastening portion 33 in the thickness direction. The abutting surface 29 is a surface provided on the back surface of the fastening portion 33 in the thickness direction that abuts against the fixing surface 31. The fastener 21 has a fastening surface 21b that abuts against the receiving surface 27 in the thickness direction. The rough surfaces 27a, 29a, 31a are provided on at least one of the abutting surface 29, the fixing surface 31, and the receiving surface 27, and have a hardness that is set by heat treatment.

[0017] The fixed surface 31 may be provided on the end of the fixed shaft 13 facing the opening provided in the housing base 17 .

[0018] The hardness of the rough surfaces 27a, 29a, 31a can be set appropriately depending on the counterpart, and in one embodiment, may be set higher than the counterpart.

[0019] The mating side may have a roughened surface 31a that is mated with the roughened surface 29a.

[0020] The hardness of the roughened surface 31a can be set appropriately, and in one embodiment, may be set to the same hardness as that of the roughened surface 29a.

[0021] The fixed shaft 13 may be a shaft for supporting the recording medium 5 .

[0022] The fixed shaft 13 may be, for example, a shaft that rotatably supports a recording medium such as a disk 5 or a magnetic tape. Alternatively, the fixed shaft 13 may be the shaft of a carriage that rotatably supports a head for reading and writing information.

[0023] The cover 19 has a main body 20 and a fastening portion 33. The fastening portion 33 has rough surfaces 27a and 29a on at least one of the front and back surfaces, the rough surfaces having a hardness set by heat treatment.

[0024] The manufacturing method of the cover 19 is to roughen the cover 19 to form a rough portion on at least the front or back surface of the cover 19 that is rougher than the unprocessed portion of the cover 19, and to heat-treat at least the rough portion to obtain the rough surfaces 27a and 29a with set hardness.

[0025] The roughening process can be performed by, for example, blasting, laser processing, roughening plating, or the like. [Example]

[0026] [Recording Device] Fig. 1 is a rear view of a cover used in a magnetic disk device according to a first embodiment. Fig. 2 is a schematic cross-sectional view of the magnetic disk device taken along line II-II of the cover in Fig. 1. Fig. 3 is a schematic cross-sectional view showing a fastening portion of the cover in Fig. 2 together with a disk. Fig. 4 is a schematic cross-sectional view showing the relationship between the hub, spindle shaft, and spindle motor in Fig. 2.

[0027] As shown in FIGS. 1 to 4, the recording device 1 is a hard disk drive serving as a magnetic disk device, and houses an internal mechanism (not shown) in a housing 3, including a plurality of disks 5 serving as recording media that rotate around an axis.

[0028] The recording medium 1 is not limited to a magnetic disk device, but may be another disk device such as an optical disk device, or a recording device other than a disk device. For example, the recording device may be a tape-embedded drive. In this case, the recording medium is a tape film wound between tape reels and rotated around the axis of the tape reels.

[0029] The plurality of disks 5 are supported by a hub 9 of a spindle motor 7. The hub 9 is supported so as to be rotatable relative to a spindle shaft 13. The spindle motor 7 drives the hub 9 to rotate relative to the spindle shaft 13.

[0030] A spacer 11 is interposed between adjacent disks 5 in the axial direction. The disk 5 at the upper end of the spindle shaft 13 in the axial direction is held by a clamp 15. Information is read and written to these disks 5 via a head (not shown).

[0031] The spindle shaft 13 is a fixed shaft in this embodiment, and is a shaft for supporting the disk 5, which is a recording medium. The fixed shaft may also be a carriage that rotatably supports a head gimbal assembly (not shown) that supports a head.

[0032] The lower axial end of the spindle shaft 13 is fixed to the bottom of a housing base 17 that forms the lower part of the housing 3. The upper axial end of the spindle shaft 13 is fastened to a cover 19 of the housing 3 by a bolt 21, which is a fastener.

[0033] The housing base 17 has a box-like configuration with a wall portion 17a on its outer periphery. The housing base 17 has an opening defined by the wall portion 17a at the upper end in the axial direction of the spindle shaft 13. The material of the housing base 17 is a metal such as aluminum, but is not limited to this.

[0034] The opening of the housing base 17 is closed by a cover 19. Therefore, the cover 19 closes the opening of the housing base 17 and constitutes the housing 3 together with the housing base 17.

[0035] The cover 19 is made of a metal plate such as stainless steel. The cover 19 has a main body 20 and a fastening portion 33 for fastening, which will be described later. A gasket 23 is interposed between the cover 9 and the housing base 19. This seals the space inside the housing 3 that houses the disk 5. Note that it is also possible to configure the space inside the housing 3 to be closed by the cover 9, but not to seal it by omitting the gasket 23.

[0036] [Cover fixing structure] FIG. 5 is a schematic cross-sectional view showing a part of the fixing structure of the cover of FIG.

[0037] 2, 3, and 5, the cover 19 is fastened and fixed to the housing base 17 by a fastening structure. This fastening structure fastens a fastening portion 33 of the cover 19 to a fastening surface 31 for fastening.

[0038] The fixing surface 31 is a surface to which the cover 19 is fastened and is provided on the housing base 17. In this embodiment, the fixing surface 31 is provided on the end (the upper end in the axial direction in this embodiment) of the spindle shaft 13 that faces the opening of the housing base 17. Note that the fixing surface 31 may also be provided on the wall portion 17a of the housing base 17.

[0039] The fixing surface 31 is a plane perpendicular to the axis of the spindle shaft 13, but may also be an inclined surface inclined with respect to the axis of the spindle shaft 13. The fixing surface 31 has a hole 13a at the axis position of the spindle shaft 13. The hole 13a is a female thread for fastening the cover 19. The spindle shaft 13 may have a male thread instead of a female thread.

[0040] The fastening portion 33 is a part of the cover 19 that is fastened to the fixing surface 31. The fastening portion 33 protrudes from the main body 20 toward the spindle shaft 13 inside the housing 3, and is concave on the front surface in the thickness direction of the cover 19 and convex on the back surface. The thickness direction coincides with the axial direction. Hereinafter, the axial direction will be used synonymously with the thickness direction. The front surface of the cover 19 is the surface located outside the housing 3, and the back surface is the surface located inside the housing 3. This fastening portion 33 has a receiving surface 27 and a contact surface 29 on the front and back surfaces in the axial direction, respectively.

[0041] The receiving surface 27 is a surface that receives the head portion 21c of the bolt 21 (described later) on the surface of the fastening portion 33 in the axial direction. The abutting surface 29 is a surface that abuts against the fixing surface 31 in the axial direction. The receiving surface 27 and the abutting surface 29 are flat surfaces that are perpendicular to the axis of the spindle shaft 13, but may also be inclined surfaces that are inclined with respect to the axis of the spindle shaft 13.

[0042] A through hole 25 is provided along the axial direction between the receiving surface 27 and the facing surface 29. The through hole 25 communicates with the hole 13a of the spindle shaft 13. The fastening portion 33 is fastened to the fixing surface 31 via the through hole 25 by a bolt 21 serving as a fastener. Note that if a male thread is provided on the spindle shaft 13, a nut may be used as the fastener instead of the bolt 21. The fastener is not limited to the bolt 21, and may be a rivet or the like.

[0043] The bolt 21 has a fastening surface 21b that axially abuts against the receiving surface 27. In this embodiment, the bolt 21 has a shank 21a and a head 21c, and the periphery of the shank 21a of the head 21c forms the fastening surface 21b. The shank 21a is a male thread and protrudes toward the fastening surface 21b side of the head 21c.

[0044] In this embodiment, the surface 29 is formed as a rough surface 29a. Therefore, the fastening portion 33 of the cover 19 has a hardness set by heat treatment on at least one of the front and back surfaces.

[0045] Rough surface 29a has irregularities set within a range less than the thickness of cover 19, for example, irregularities of about 0.8 μm. Rough surface 29a is formed over the entire surface 29, but may be formed only partially. This rough surface 29a is mated with fixed surface 31, which is the counterpart, by fastening with bolts 21.

[0046] In this embodiment, the hardness of the rough surface 29a is higher than the hardness of the fixing surface 31, and the rough surface 29a bites into the fixing surface 31. This biting prevents the rough surface 29a from sliding against the fixing surface 31.

[0047] The roughening of the cover 29 is performed by abrasive processing. In this embodiment, the roughening is performed by blasting. In the blasting, it is preferable to use a projectile made of the same material as the cover 19. By performing the roughening processing on the cover 19, a rough portion is formed that is rougher than the unprocessed portion of the cover 19 that has not been roughened.

[0048] The roughening process may be performed on the entire back surface or the entire front and back surfaces of the cover 19. The roughening of the surface 29 can also be performed by other roughening processes such as laser processing or roughening plating. In laser processing, the surface 29 is roughened using a pulse laser or the like. In roughening plating, the surface 29 is roughened using, for example, matte or semi-bright nickel plating.

[0049] The rough portion, which is the roughened front surface 29, is hardened by heat treatment to form a rough surface 29a. In this embodiment, the rough surface 29a has a higher hardness than the fixing surface 31, which is the counterpart.

[0050] However, it is sufficient that rough surface 29a suppresses slippage relative to fixed surface 31. For this reason, the hardness of rough surface 29a may be an absolute hardness that suppresses slippage, rather than a relative hardness relative to the mating fixed surface 31. In this case, the hardness of rough surface 29a of front surface 29 may be not only higher than that of fixed surface 31, but also the same as or lower than that of fixed surface 31, as the optimum hardness for suppressing slippage between front surface 29 and fixed surface 31.

[0051] The heat treatment is preferably performed by partial quenching, which is a partial heat treatment. Specifically, in partial quenching, only the fastening portion 33 of the cover 19 is heated to, for example, about 260°C and then cooled. This heat treatment not only sets the hardness of the roughened surface 29a but also forms an oxide film to suppress contamination.

[0052] In addition, in the inventors' experiments, the roughened surface 29a did not disappear even when heated to a temperature of approximately 1000°C. In this case, the blasting material remaining on the surface of the cover 19 is assimilated, reducing the risk of contamination of the cover 19. Furthermore, if the roughened surface 29a is roughened by plating, the baking step during the roughened plating process can be used as a heat treatment to set the hardness. That is, the baking step can improve the adhesion of the roughened plating, and this adhesion improvement has the effect of blending the roughened plating with the base material (cover 19), thereby achieving the set hardness of the roughened surface 29a. This eliminates the need for a separate heat treatment in the case of roughened plating, simplifying the formation of the roughened surface 29a. However, it is also possible to perform a separate heat treatment in addition to the baking step for roughened plating.

[0053] Heat treatment by partial quenching of the cover 19 can suppress deformation of the main body 20 of the cover 19. In addition, the fastening portion 33 where heat treatment is performed is convex with respect to the main body 20 of the cover 19, suppressing deformation due to heat treatment. Therefore, in this embodiment, deformation of the cover 19 as a whole can be suppressed. Note that the entire cover 19 may be heated during heat treatment.

[0054] As described above, in this embodiment, the fastening portion 33 of the cover 19 is fastened to the fixing surface 31 of the spindle shaft 13 by the bolt 21. At this time, the rough surface 29a of the front surface 29 of the fastening portion 33 is aligned with the fixing surface 13 of the spindle shaft 13. Therefore, the rough surface 29a of the cover 19 prevents slippage between the fastening portion 33 and the fixing surface 13 of the spindle shaft 13.

[0055] Therefore, tilting of the spindle shaft 13 relative to the housing 3 and displacement of the spindle shaft 13 relative to the cover 19 can be more reliably prevented.

[0056] Furthermore, in this embodiment, the hardness of the rough surface 29a for preventing slippage is set by heat treatment, so that contamination can be prevented by forming an oxide film or the like.

[0057] In addition, in this embodiment, the rough surface 29a of the first surface 29 is set to have a higher hardness than the mating fixed surface 31, so that the rough surface 29a bites into the fixed surface 31, more reliably suppressing slippage between the first surface 29 and the fixed surface 31.

[0058] [Variations] FIG. 6 is a schematic cross-sectional view showing a fastening portion of a cover according to a modified example of the first embodiment.

[0059] In the modified example of Fig. 6, the forward surface 29 is flat and the receiving surface 27 is provided with a rough surface 27a. Note that the rough surface may be provided on both the forward surface 29 and the receiving surface 27. Furthermore, the rough surface 27a is provided on the entire receiving surface 27, but it may be provided on only a part of it.

[0060] The hardness of the rough surface 27a is set to be higher than that of the fastening surface 21b of the bolt 21, which is the mating side.

[0061] Therefore, the same effects as those described above can be achieved in the modified example as well. [Example]

[0062] 7 is a schematic cross-sectional view showing a fastening portion of a cover according to Example 2 of the present invention. Note that Example 2 has the same basic configuration as Example 1, and the same or corresponding components are designated by the same reference numerals, and redundant explanations will be omitted.

[0063] In this embodiment, the contact surface 29 is provided with a rough surface 29a, and the fixing surface 31 is provided with a rough surface 31a. That is, the fixing surface 31, which is the counterpart, has the rough surface 31a with which the rough portion 29a is fitted.

[0064] The roughened surface 31a can be formed in the same manner as the roughened surface 29a. However, the roughened surface 31a is set to the same hardness as the roughened surface 29a. Note that the roughened surface and the roughened surface are relative terms, and the fixed surface 29 may have the roughened surface, and the fixed surface 31 may have the roughened surface. The rest is the same as in Example 1.

[0065] In this embodiment, in addition to the same effects as those of the first embodiment, the engagement between the rough surface 29a and the rough surface 31a can more reliably suppress slippage between the front surface 29 and the fixed surface 31. [Example]

[0066] 8 is a schematic cross-sectional view showing a fastening portion of a cover according to Example 3 of the present invention. Note that Example 2 has the same basic configuration as Example 1, and the same or corresponding components are designated by the same reference numerals, and redundant explanations will be omitted.

[0067] In the third embodiment, unlike the first embodiment, the abutting surface 29a is configured as a flat surface and the fixing surface 31 is provided with a rough surface 31a. The rough surface 31a can be formed in the same manner as in the first embodiment.

[0068] The hardness of the rough surface 31a is set to be higher than that of the mating surface 29. The rest is the same as in the first embodiment.

[0069] Therefore, the third embodiment can also achieve the same effects as the first embodiment. [Explanation of symbols]

[0070] 1. Recording device 3. Housing 5. Disk (recording medium) 13 Spindle shaft (fixed shaft) 17 Housing Base 19 Cover 21 Bolts (fasteners) 21b Fastening surface 27 Receiving surface 27a Rough surface 29 For the time being 29a Rough surface 31 Fixed surface 31a Rough surface 33 Fastening part

Claims

1. A recording device that accommodates a recording medium in a housing having an opening in a housing base that is closed by a cover, a fastening surface provided on the housing base; a fastening portion provided on the cover and fastened to the fixing surface; a receiving surface on a surface in a thickness direction of the fastening portion; a surface of a rear surface of the mounting portion in the thickness direction that abuts against the fixing surface; a fastener having a fastening surface that abuts against the receiving surface in the thickness direction; a roughened surface provided on at least one of the first surface, the fixing surface, and the receiving surface, the roughened surface having a hardness set by heat treatment; A recording device comprising:

2. 2. The recording device of claim 1, The fixing surface is provided on an end of a fixing shaft that is provided on the housing base and faces the opening. Recording device.

3. 3. The recording device of claim 1, The rough surface is set to have a higher hardness than the mating surface. Recording device.

4. 3. The recording device of claim 1, The mating side of the rough surface has a roughened surface to which the rough surface is mated. Recording device.

5. 5. The recording device of claim 4, The roughened surface has the same hardness as the roughened surface set by heat treatment. Recording device.

6. 3. The recording device of claim 2, the fixed shaft is a shaft for rotatably supporting the recording medium; Recording device.

7. a cover for closing an opening of a housing base and accommodating a recording medium in the housing, A main body portion and a fastening portion for fastening are included. The fastening portion has a rough surface having a hardness set by heat treatment on at least one of the front surface and the back surface. cover.

8. A method for manufacturing the cover of claim 7, roughening the cover to form a rough portion on at least the front surface or the back surface, the rough portion having a roughness greater than that of an unprocessed portion of the cover; and heat-treating at least the rough portion to obtain the rough surface having a set hardness. How the cover is manufactured.

9. A method for manufacturing the cover of claim 7, The roughening process is a blasting process, a laser process, or a roughening plating process. How the cover is manufactured.

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