WO2001073788A1

WO2001073788A1 - Hard disk cover

Info

Publication number: WO2001073788A1
Application number: PCT/JP2000/001878
Authority: WO
Inventors: Mitsuo Hori; Tatsuya Aoki
Original assignee: Shishiai-Kabushikigaisha
Priority date: 2000-03-27
Filing date: 2000-03-27
Publication date: 2001-10-04

Abstract

A cover that covers a hard disk contained in a personal computer or the like. Particularly, a hard disk cover that is capable of efficiently reducing the noise produced during the driving of the hard disk and that is easy to produce and is inexpensive. This hard disk cover, which is a cover for covering a hard disk, is characterized by comprising a cover main body, and a vibration controlling sheet stuck to the outer surface of the cover main body, the vibration controlling sheet containing, in the sheet material, an active component that increases the amount of dipolar moment in the sheet material.

Description

¾ ^ Itoda »Hard Disk Cover Technical Field

The present invention relates to a cover for covering a hard disk built in a personal computer or the like. More specifically, the present invention relates to a hard disk cover that can efficiently reduce noise generated when a hard disk is driven, and that is easy and inexpensive to manufacture. Background art

Conventionally, hard disks built into personal computers and the like are directly screwed to the housing and covered with an aluminum cover.

This hard disk is known to generate noise when driven. As a specific countermeasure example of the noise generated when the hard disk is driven, for example, as shown in FIG. 6, a cover body 1 itself was produced by bending a damping steel plate 2 by bending. In addition, as shown in FIG. 7, there was a case where a stainless steel foil 7 was attached to the outer surface of the cover body 5 via an adhesive layer 6.

However, the cover shown in Fig. 6 is manufactured by bending and forming a damping steel sheet having a sandwich structure in which a damping sheet is sandwiched between steel sheets, so that the cover cannot be bent correctly to the shape of the cover. There was a problem. On the other hand, the cover shown in Fig. 7 has sufficient vibration damping performance, but uses expensive stainless steel foil, which goes against the trend of cost reduction in the computer industry in recent years. As such, its use was shunned.

The present invention has been made in view of such circumstances, and provides a hard disk cover that can efficiently reduce noise generated when a hard disk is driven, and that is easy to manufacture and inexpensive. Also for the purpose It is. Disclosure of the invention

The hard disk cover (hereinafter, simply referred to as a cover) of the present invention includes a cover body 21 and a vibration damping sheet 22 as shown in FIG. The cover body 21 is made of an aluminum plate made of aluminum or an aluminum alloy, and has a hard disk D directly screwed to the housing 20 and a drive mechanism such as a drive motor for rotating the hard disk D (see the figure). It is molded to the size and shape to cover

A vibration damping sheet 22 is attached to the outer surface of the cover body 21 via an adhesive layer 23. Examples of the sheet material constituting the vibration damping sheet 22 include polyvinyl chloride, polyethylene, chlorinated polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polyvinylidene fluoride, polyisoprene, and polystyrene. Styrene-butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), isoprene rubber ( Polymer materials such as IR) and blends of these.

Figure 1 shows the arrangement of dipoles 12 inside the damping sheet 11 before the vibration energy is propagated. It can be said that the arrangement state of the dipoles 12 is in a stable state. However, due to the propagation of the vibration energy, the dipoles 12 existing inside the damping sheet 11 1 are displaced, and as shown in FIG. 2, each dipole 12 inside the damping sheet 11 is It will be placed in an unstable state, and each dipole 12 will try to return to a stable state as shown in FIG.

At this time, energy is consumed. It is considered that the vibration energy is absorbed through the displacement of the dipole inside the damping sheet 11 and the energy consumption by the dipole restoring action. Due to such a mechanism of vibration absorption, the larger the amount of dipole moment inside the damping sheet 11 as shown in FIGS. 1 and 2, the more the damping sheet 11 has It is considered that the energy absorption performance also increases. The active ingredient has the function of dramatically increasing the amount of dipole moment inside the damping sheet. The active component itself has a large dipole moment amount or the active component itself has a small dipole moment amount, but when mixed with the sheet material, the dipole moment amount inside the damping sheet A component that can dramatically increase the amount of water.

For example, when vibration energy of a predetermined magnitude is applied to a vibration damping sheet under a predetermined temperature condition, the amount of dipole moment generated inside the vibration damping sheet formed by sufficiently melting the sheet material and the active component is: As shown in Fig. 3, under the same conditions, the amount of dipole moment generated inside the damping sheet containing no active ingredient increases to 3 times, the force, and 1 ° times the amount of dipole moment. It is. Along with this, the energy consumption due to the dipole restoration operation when the above-mentioned energy is added will also increase dramatically, and it is thought that the vibration energy absorption performance far exceeds the prediction . Examples of active ingredients that induce such effects include N, N-dicyclohexylbenzothiazyl-2-sulfenamide (DCHBSA), 2-mercaptobenzozothiazole (MBT), and dibenzothiazylsulfide (MBTS). , N-cyclohexylbenzothiaziruyl 2-snolephenamide (CBS), N-tert-butylbenzothiazirulu-2-sulfenamide (BBS), N-oxydiethylenebenzothiazirulu-2-sulfenamide ( OBS), N, N-diisopropylbenzothiazyl_2-sulfenamide (DPBS) and other benzothiazyl group-containing compounds.

Benzotriazole with an azole group bonded to the benzene ring as the mother nucleus, and a phenyl group bonded to the nucleus. 2- (2'-hydroxyl-3 '-(3 ", 4", 5 ", 6" 1) 5'-methyl Phenyl} —Benzotriazole (2HPMMB), 2— {2′-one-hydroxyl 5′—methylphenyl} —benzotriazole (2HMPB), 2- {2′-one-hydroxyl 3′—t 1-butyl-1-5'-methylphenyl} 1-5-chlorobenzototriazole (2HBMPCB), 2- {2'-dihydroxy-1-3 ', 5'-dibutylbutyrolene} -5-chloro Mouth One or more compounds selected from compounds having a benzotriazole group such as benzotriazole (2HDBPCB),

One or more compounds selected from compounds having a diphenylacrylate group such as ethyl-2-cyano-3,3-diphenylacrylate;

Alternatively, compounds having a benzophenone group, such as 2-hydroxy-14-methoxybenzophenone (HMBP) and 2-hydropenoxy-4-methoxybenzophenone-15-snorrephonic acid (HMBPS). One or more selected from the group consisting of:

The content of the active ingredient is preferably from 10 to 200 parts by weight per 100 parts by weight of the sheet material. For example, when the content of the active ingredient is less than 10 parts by weight, the effect of increasing the amount of dipole moment cannot be obtained, and when the content of the active ingredient exceeds 200 parts by weight, However, they may not be sufficiently compatible or may not have sufficient sheet strength.

In determining the active component contained in the vibration damping sheet, it is preferable to select a material having a similar value in consideration of the compatibility between the active component and the sheet material, that is, the SP value.

The amount of the dipole moment varies depending on the type of the above-mentioned sheet material and active ingredient. Also, even when the same sheet material or active ingredient is used, the amount of dipole moment varies depending on the temperature at which the vibrational energy is transmitted. Also, the magnitude of the dipole moment changes depending on the magnitude of the transmitted vibrational energy. For this reason, considering the temperature and vibration energy when applying the cover, the maximum It is desirable to select and use a sheet material and an active ingredient so as to obtain a large dipole moment.

The above-mentioned active ingredients are not limited to one kind, and two or more kinds can be mixed. In this case, at least two or more active components having different glass transition points can be included in the sheet material to extend the temperature range in which vibration absorption is exhibited. For example, a combination of DCHP and DCHBSA, and a combination of DCHP, DCHBSA and ECDPA can be mentioned.

In addition to the active ingredient, the above-mentioned sheet material is filled with fillers such as my scales, glass pieces, glass fiber, carbon fiber, calcium carbonate, barite, and precipitated barium sulfate for the purpose of further improving the absorption performance. You can also. Filler amount is 10 ~ 90 weight

% Is preferred. For example, when the filling amount of the filler is less than 10% by weight, the absorption performance is not sufficiently improved even if the filler is filled, and conversely, even if the filling amount of the filler exceeds 90% by weight. However, if filling could not be actually performed, or if the mechanical strength of the vibration damping sheet formed of the sheet material is reduced, adverse effects would be caused.

The vibration damping sheet applied to the cover of the present invention is formed into a sheet by mixing the above-mentioned sheet material, active component, and filler with known molding means. In this case, other sheets such as a bulking agent and a coloring agent are used. Components can also be added as needed.

It should be noted that the scope of the present invention is defined in “Claims”, and all changes and modes included in the scope can be adopted. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram showing a dipole inside the damping sheet.

FIG. 2 is a schematic diagram showing a state of a dipole inside the vibration damping sheet when vibration energy is transmitted.

Figure 3 shows the dipole inside the damping sheet when the active ingredient is blended. FIG. 4 is a schematic view showing the state of FIG.

FIG. 4 is a partially cutaway perspective view showing a cover that covers the hard disk. FIG. 5 is a graph showing the sum of the sound pressure levels of the embodiment and Comparative Examples 1 and 2.

FIG. 6 is an enlarged sectional view showing a conventional cover.

FIG. 7 is an enlarged sectional view showing another conventional cover. Example

Fig. 4 shows a hard disk D (cantilever support type HD) directly screwed to the housing 20. The hard disk D and a drive mechanism (not shown) such as a drive motor for rotating the hard disk D are covered with a cover. ing.

The cover includes a cover body 21 made of an aluminum plate and a vibration damping sheet 22 attached to the outer surface of the cover body 21 via an adhesive layer 23.

In the vibration damping sheet 22, DCHB SA1 was added at a rate of 5.4% by weight to CPE 16.6% by weight, and further, 68% by weight of my force scale and 2% by weight of a flame retardant were added. Then, the mixture was put into a kneading roll set at 160 ° C and kneaded, and the obtained kneaded material was sandwiched between dies heated to 180 ° C and heated for 180 seconds. A sheet pressed to a thickness of 1 mm using a press machine at a pressure of 80 kg · f / cm ² for 30 seconds was used.

The hard disk D is rotated while being covered with the cover according to this embodiment, and the sound pressure at a plurality of sound pressure measurement points on the cover at that time is measured with a condenser microphone, and the sum of the sound pressure levels is plotted. 5

In addition, as a comparison, when the cover body of the above embodiment was covered with a conventional cover in which stainless steel foil was stuck via an adhesive (Comparative Example 1), when the cover body was covered with a cover having only the cover body (Comparative Example) Similarly, for Example 2), the sound pressure on each force bar was measured, and the sum of the sound pressure levels is shown in Fig. 5.

From Fig. 5, the cover according to Comparative Example 2 consisting of only the cover body is 92 d Compared to B, the cover of Comparative Example 1 with the stainless steel foil attached was 88 dB, the sound pressure was reduced by as much as 14 dB, and it had excellent vibration absorption. Was confirmed.

However, the cover according to the working example had a sound pressure drop of 85.9 dB, a drop of as much as 16.1 dB, and had excellent vibration absorption far exceeding that of the cover of Comparative Example 2. It was confirmed that.

Claims

Scope of word blue

1. A cover that covers the hard disk,

A cover body, and a vibration damping sheet attached to the outer surface of the cover body, wherein the vibration damping sheet contains an active ingredient in the sheet material that increases the amount of dipole moment in the sheet material. Hard disk cover.

2. The active ingredient is one or more compounds selected from compounds having a benzothiazyl group, compounds having a benzotriazole group, compounds having a diphenylacrylate group, and compounds having a benzophenone group. 2. The hard disk cover according to claim 1, wherein:

3. The hard disk cover according to claim 1, wherein the active ingredient is contained in an amount of 100 to 200 parts by weight based on 100 parts by weight of the sheet material.