Recording device and cover

Abstract

Provided is a recording device with which the sealing performance of a gasket having a narrow portion can be improved. The recording device comprises a base 17 in which an internal mechanism 5 is accommodated in a space 3a having an opening part 17a, a cover 19 that is attached to the opening part 17a of the base 17 and that closes the space 3a, and a gasket 29 that extends in a circumferential manner along an outer circumferential part 19a of the cover 19 and that is compressed by contact with the base 17. The gasket 29 includes a wide part 31 of which the width extending from the inside to the outside of the circumferential form is relatively large, and a narrow part 33 of which said width is relatively small. One or both of the cover 19 and the base 17 is provided with a protrusion 37 in the compression direction of the gasket 29, the protrusion increasing the compression ratio of the narrow part 33 in a portion corresponding to the narrow part 33.

Description

Technical Field

[0001] The present invention relates to a recording device such as a hard disk drive and a cover used for the recording device.

Background Art

[0002] A hard disk drive as a recording device houses an internal mechanism including a disk as a recording medium in a space portion, and sealing is required so that dust, moisture, etc. do not enter the space portion.

[0003] In order to ensure such sealing, it is common to provide a gasket between the base and the cover of the housing that partitions the space portion (for example, Patent Document 1). The gasket is provided in a circumferential shape along the outer peripheral portion of the cover that is received by the base, and is compressed and interposed between the cover and the base.

[0004] Due to space constraints, this gasket may sometimes have a narrow portion with a reduced width that partially extends around the inside and outside. The narrow portion can be easily set by changing the discharge conditions such as the discharge amount when applying and curing a liquid gasket discharged from a discharge tool such as a needle to the cover.

[0005] However, since the protruding height from the cover is determined to some extent according to the width when the liquid gasket is discharged, the protruding height becomes smaller compared to other parts of the gasket, which may reduce the sealing performance of the gasket.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem we are trying to solve is that the protrusion height becomes small in the narrow section of the gasket, which could lead to a decrease in sealing performance. [Means for solving the problem]

[0008] The present invention provides a recording device comprising: a base that houses an internal mechanism within a space having an opening; a cover attached to the opening of the base to close the space; and a gasket that extends circumferentially along the outer circumference of the cover and is compressed by contact with the base. The gasket comprises a wide portion with a relatively large width extending both inside and outside the circumferential shape and a narrow portion with a relatively small width. The cover or the base is provided with a projection in the compression direction of the gasket in the portion corresponding to the narrow portion, which increases the compression ratio of the narrow portion.

[0009] Furthermore, the present invention provides a cover that is attached to an opening in a base that houses an internal mechanism within a space and closes the space. The cover comprises an outer periphery that is received by the base, and a gasket that extends circumferentially along the outer periphery and is compressed by contact with the base. The gasket comprises a wide portion with a relatively large width and a narrow portion with a relatively small width over the circumferential inner and outer surfaces. The outer periphery is provided with a projection in the compression direction of the gasket in the portion corresponding to the narrow portion, which increases the compression ratio of the narrow portion. [Effects of the Invention]

[0010] According to the present invention, the protrusions can increase the compression ratio of the narrow width portion with a small protrusion height, thereby improving the sealing performance of the gasket. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a plan view of a recording device according to Embodiment 1 of the present invention. [Figure 2] Figure 2(A) is a schematic cross-sectional view of the recording device shown in Figure 1 along line II-II, and Figure 2(B) is a schematic cross-sectional view of a modified example. [Figure 3]Figures 3(A) and 3(B) are schematic cross-sectional views showing an enlarged portion of Figure 2(A). [Figure 4] Figure 4 is a bottom view of the cover of the recording device shown in Figure 1. [Figure 5] Figure 5 is a bottom view of the cover, showing an enlarged view of the area around the narrow portion of the gasket in Figure 4. [Figure 6] Figure 6(A) is a longitudinal cross-sectional view relating to the line VI-VI in Figure 5, and Figure 6(B) is a longitudinal cross-sectional view showing the cover in Figure 6(A) before it is attached to the base. [Figure 7] Figure 7(A) is a cross-sectional view relating to the VIIA-VIIA line in Figure 5(A), and Figure 7(B) is a transverse cross-sectional view relating to the VIIB-VIIB line in Figure 5(A). [Figure 8] Figure 8 is a cross-sectional view showing the area around the narrow portion of the gasket, relating to a modified example of Embodiment 1 of the present invention. [Figure 9] Figure 9(A) is a longitudinal cross-sectional view showing the area around the narrow portion of the gasket according to Embodiment 2 of the present invention, and Figure 9(B) is a longitudinal cross-sectional view showing the cover of Figure 9(A) before it is attached to the base. [Figure 10] Figure 10 is a cross-sectional view relating to line XX in Figure 9(A). [Figure 11] Figures 11(A) to (C) relate to a modified example of Example 2 and are cross-sectional views showing the area around the narrow portion of the gasket. [Figure 12] Figure 12 is a longitudinal cross-sectional view showing the area around the narrow portion of the gasket according to Embodiment 3 of the present invention. [Figure 13] Figure 13 is a bottom view of the cover showing the area around the narrow portion of the gasket according to Embodiment 4 of the present invention. [Modes for carrying out the invention]

[0012] The objective of improving the airtightness of a gasket with a narrow section was achieved by providing a projection that increases the compression ratio of the narrow section.

[0013] As shown in the figure, the recording device 1 includes a base 17, a cover 19, and a gasket 29. The base 17 houses an internal mechanism 5 in a space portion 3a having an opening 17a. The cover 19 is attached to the opening 17a of the base 17 to close the space portion 3a. The gasket 29 extends circumferentially along the outer peripheral portion 19a of the cover 19 and is compressed by contacting the base 17. The gasket 29 includes a wide portion 31 having a relatively large width extending around the inside and outside, and a narrow portion 33 having a relatively small width. One or both of the cover 19 and the base 17 include a protruding portion 37 in the compression direction of the gasket 29 that increases the compression rate of the narrow portion 33 at a portion corresponding to the narrow portion 33.

[0014] The gasket 29 may include a transition portion 35 between the wide portion 31 and the narrow portion 33, where the height in the compression direction gradually decreases from the wide portion 31 toward the narrow portion 33.

[0015] When the protruding portion 37 is provided on the cover 19, the end portion 37a in the extending direction of the protruding portion 37 may be located within the transition portion 35. In this case, the end portion 37a of the protruding portion 37 gradually increases in height in the compression direction from the portion on the wide portion 31 side to the portion on the narrow portion 33 side in the extending direction.

[0016] When the protruding portion 37 is provided on the base 17, the end portion 37a in the extending direction of the protruding portion 37 may be located opposite to the transition portion 35. In this case, the end portion 37a of the protruding portion 37 gradually increases in height in the compression direction from the portion on the wide portion 31 side to the portion on the narrow portion 33 side in the extending direction.

[0017] The narrow portion 33 and the wide portion 31 may be eccentric in the width direction of the gasket 29.

[0018] The protruding portion 37 is formed smaller in the width direction of the gasket 29 than the narrow portion 33, and the protruding portion 37 and the narrow portion 33 may be eccentric in the width direction.

[0019] The cover 19 used in the recording device 1, which has a projection 37, has a gasket 29 extending circumferentially along the outer peripheral portion 19a that is supported by the base 17. The gasket 29 has a wide portion 31 with a relatively large width extending both inside and outside the circumference, and a narrow portion 33 with a relatively small width. The outer peripheral portion 19a has a projection 37 in the compression direction of the gasket 29 that increases the compression ratio of the narrow portion 33 in the portion corresponding to the narrow portion 33. [Examples]

[0020] [Recording device configuration] Figure 1 is a plan view of a recording device according to Embodiment 1 of the present invention. Figure 2(A) is a schematic cross-sectional view of the recording device of Figure 1 along line II-II, and Figure 2(B) is a schematic cross-sectional view of a modified example.

[0021] In this embodiment, the recording device 1 is a hard disk drive as a magnetic disk device, and its internal mechanism 5 is housed in the space 3a within the housing 3.

[0022] The internal mechanism 5 includes a disk 7 as a recording medium, as well as a spindle motor 9 and the like. Multiple disks 7 are stacked in the thickness direction of the recording device 1 (hereinafter simply referred to as the "thickness direction") and are rotatably supported by the spindle motor 9. Information is read from and written to these disks 7 through a head (not shown).

[0023] Note that the recording device 1 is not limited to a magnetic disk drive, but may be other disk drives such as an optical disk drive, or other recording devices other than disk drives. For example, the recording device 1 may be a tape-embedded drive as shown in Figure 2(B). In this recording device 1, the tape film 13 as a recording medium wound between two tape reels 11 and the head assembly 15 for reading and writing information are housed as an internal mechanism 5 in the space 3a of the housing 3.

[0024] The housing 3 consists of a base 17 and a cover 19, and seals or encloses the inside.

[0025] The base 17 is made of a metal such as aluminum and is constructed in a box shape with an opening 17a on one side in the thickness direction that communicates with the space 3a. The base 17 only needs to be box-shaped capable of housing the internal mechanism 5 including the disk 7, and any suitable shape can be adopted to that extent. In this embodiment, the base 17 is, for example, substantially rectangular in plan view. Note that "plan view" means the view from the thickness direction and does not distinguish between the top surface and the bottom surface.

[0026] The base 17 is closed by attaching a cover 19 to one of the openings 17a in the thickness direction. This seals the space 3a within the housing 3 that houses the internal mechanism 5. This sealed space 3a may be filled with a gas that has less resistance than air, such as helium.

[0027] The outer periphery of the base 17 is provided with a side wall portion 21a in a circular manner, and the opening 17a of the base 17 is demarcated by the side wall portion 21a. The outer periphery of the base 17 is the outer periphery region surrounding the internal mechanism 5, and in this embodiment, it refers to the portion where the side wall portion 21a is provided.

[0028] The side wall portion 21a is integrally erected from the plate-shaped bottom wall portion 21b of the base 17. However, the side wall portion 21a can also be formed integrally by joining separately formed parts to the bottom wall portion 21b of the base 17.

[0029] The side wall portion 21a is provided with a fastening portion 23 and a cover receiving portion 25.

[0030] The fastening portion 23 of the base 17 is the portion that fastens the cover 19 to the base 17. In this embodiment, there are multiple fastening portions 23, for example, six, spaced apart in the circumferential direction of the base 17. The fastening portions 23 may also be formed in a circumferential shape along the outer circumference of the base 17. The circumferential direction of the base 17 refers to the circumferential direction along the side wall portion 21a of the base 17.

[0031] The fastening portion 23 receives the cover 19 by joining it in the thickness direction. In this joined state, the cover 19 is fastened to the fastening portion 23 by fasteners, such as bolts 27. The cover 19 is also fastened to the spindle motor 9 by bolts 27. In addition to bolts 27, rivets or the like may be used as fasteners.

[0032] The cover support portion 25 receives the outer periphery 19a of the cover 19, with the gasket 29 attached to the cover 19 interposed between them. This compresses the gasket 29 in the thickness direction between the cover support portion 25 and the cover 19.

[0033] In this embodiment, the cover receiving portion 25 is provided in a circumferential manner in plan view along the side wall portion 21a of the base 17. However, the cover receiving portion 25 may be provided only partially on the outer periphery of the base 17.

[0034] The cover receiving portion 25 has a receiving surface 25a. The receiving surface 25a is configured to be flat along the width direction. The gasket 29 abuts against this receiving surface 25a to receive the outer periphery 19a of the cover 19. Note that the receiving surface 25a does not have to be flat; it may have irregularities such as bumps or ridges as long as it can abut against the gasket 29.

[0035] Figure 4 is a bottom view of the cover of the recording device shown in Figure 1.

[0036] The cover 19 is made of a metal plate such as stainless steel, as shown in Figures 1 to 4. The cover 19 is formed as a flat plate that covers the opening 17a of the base 17 as a whole. In this embodiment, the cover 19 is substantially rectangular in plan view, corresponding to the base 17. However, the shape and other forms of the cover 19 are not particularly limited as long as they cover the opening 17a of the base 17. The material of the cover 19 is also arbitrary.

[0037] The cover 19 covers the opening 17a of the base 17, with its outer periphery 19a being supported by the base 17. Specifically, the outer periphery 19a of the base 17 is supported in the thickness direction by the cover receiving portion 25 of the base 17. The outer periphery 19a is a circumferential portion supported by the base 17. A sealing gasket 29 is attached to the outer periphery 19a of the cover 19.

[0038] The gasket 29 extends circumferentially along the outer circumference 19a of the cover 19. The gasket 29 protrudes in the thickness direction from the outer circumference 19a and is compressed by contact with the base 17. Specifically, the gasket 29 protruding from the outer circumference 19a of the cover 19 contacts the cover receiving portion 25 of the base 17 and is compressed and interposed between the base 17 and the cover 19 as the cover 19 is fixed to the base 17.

[0039] In this embodiment, the protrusion direction and compression direction of the gasket 29 coincide with the thickness direction, but they can be different. Furthermore, the protrusion direction and compression direction of the gasket 29 can be different as long as the gasket 29 can be compressed to ensure airtightness. In this embodiment, unless otherwise specifically required, the protrusion direction and compression direction will be described as the thickness direction.

[0040] The compressed gasket 29 seals the space between the cover 19 and the base 17. In this embodiment, the gasket 29 is compressed between the cover 19 and the cover receiving portion 25 of the base 17, sealing the space between the cover 19 and the cover receiving portion 25.

[0041] In this embodiment, the gasket 29 is a liquid gasket such as FIPG (Foamed In Place Gasket). That is, the gasket 29 is pre-applied to the outer circumference 19a of the cover 19 by dispensing from a needle or the like and fixed in place by curing.

[0042] Figure 5 is a bottom view of the cover 19, showing an enlarged view of the area around the narrow portion 33 of the gasket 29 in Figure 4. Figure 6(A) is a longitudinal section view of Figure 5 along the line VI-VI, and Figure 6(B) is a longitudinal section view of Figure 6(A) before it is attached to the base 17. Figure 7(A) is a cross section view of Figure 5(A) along the line VIIA-VIIA, and Figure 7(B) is a transverse section view of Figure 5(A) along the line VIIB-VIIB.

[0043] The gasket 29 in this embodiment includes a wide portion 31 and a narrow portion 33.

[0044] The wide portion 31 is the part of the gasket 29 that has a relatively large width both inside and outside its circumference, while the narrow portion 33 is the part of the gasket 29 that has a relatively small width both inside and outside its circumference.

[0045] The narrowed portion 33 is formed by reducing the width of a part of the gasket 29 in the extending direction due to space constraints such as avoiding interference with the internal mechanism 5. One or more narrowed portions 33 are provided in the extending direction.

[0046] The wide portion 31 and the narrow portion 33 are arranged concentrically in the width direction in a cross-section perpendicular to the extension direction of the gasket 29. Concentric means that the centers of the wide portion 31 and the narrow portion 33 in the width direction coincide in the width direction.

[0047] The width and height of these wide portions 31 and narrow portions 33 are set when the liquid gasket is dispensed from an applicator such as a needle. Specifically, the width and height of the liquid gasket when it is dispensed from the applicator and cured have a correlation that prevents either one from being made larger or smaller than the other within a single layer. The width and height of the wide portions 31 and narrow portions 33 are set according to this correlation. For this reason, the height of the narrow portion 33 is lower than that of the wide portion 31, in proportion to its width.

[0048] The widths of the wide section 31 and the narrow section 33 refer to the largest width (maximum width) in the wide section 31 and the narrow section 33, respectively, in the free state, but they may also be the smallest width (minimum width) or the average width. The widths of the wide section 31 and the narrow section 33 are constant, but they may be varied in the extension direction. The free state is an unloaded state in which no compressive load is acting on the gasket 29, and in this embodiment, it is the pre-closed state before the opening 17a of the base 17 is closed by the cover 19.

[0049] The heights of the wide section 31 and the narrow section 33 refer to the largest height (maximum height) in the wide section 31 and the narrow section 33, respectively, in a free state, but they may also be the smallest height (minimum height) or the average height. The heights of the wide section 31 and the narrow section 33 are constant, but they may be varied in the extension direction.

[0050] The width (and height) of the wide section 31 and the narrow section 33 can be adjusted by changing discharge conditions such as the discharge amount of the gasket 29, the movement speed of the applicator such as a needle, and the distance between the applicator and the coating surface of the cover 19. The movement speed of the applicator refers to the movement speed in the extension direction.

[0051] A transition section 35 is provided between the narrow section 33 and the wide section 31. The transition section 35 gradually decreases in width and height from the wide section 31 towards the narrow section 33. Gradual decrease in width and height means that the width and height decrease continuously or in steps. In this embodiment, the transition section 35 has inclined surfaces on both sides in the width direction and the surface in contact with the cover 19, which will be described later, and the width and height are reduced, but the shape can be arbitrarily set.

[0052] For example, the width and height of the transition section 35 may decrease in a parabolic shape, or one side may be inclined and the other parabolic. Furthermore, as a shape in which the width and height gradually decrease, it may be a shape in which multiple sections with continuously decreasing width and height are connected by sections with constant width and height, or a shape in which multiple sections with constant width and height but different widths and heights are connected.

[0053] In the portion of the gasket 29 corresponding to the narrow portion 33, the cover 19 is provided with a projection 37. The projection 37 is a projection in the thickness direction, which is the compression direction of the gasket 29, that increases the compression ratio of the narrow portion 33. The portion of the cover 19 corresponding to the narrow portion 33 refers to the portion where the narrow portion 33 is provided. Therefore, in this embodiment, the projection 37 raises the narrow portion 33. Raising means making the narrow portion 33 higher in the thickness direction compared to when the projection 37 is not present.

[0054] The compression ratio can be expressed as (Hh) / H, where h is the height of the gasket 29 in the compressed state and H is the height of the gasket 29 in the free state. Increasing the compression ratio of the narrow section 33 means increasing the compression ratio of the narrow section 33 compared to when there is no protrusion 37. This increase in the compression ratio of the narrow section 33 can be made larger, smaller, or the same as the compression ratio of the wide section 31. In any case, it is preferable to make the difference between the compression ratio of the narrow section 33 and the compression ratio of the wide section 31 small.

[0055] This configuration suppresses fluctuations in the protrusion height in the thickness direction of the gasket 29 in its free state between the narrow portion 33 and the wide portion 31, and increases the compressibility of the narrow portion 33. This makes it possible to improve the sealing performance of the gasket 29.

[0056] Note that the protrusion height refers to the height in the thickness direction of the gasket 29 from the portion of the cover 19 without the protrusion 37, and is different from the height of the gasket 29 in the thickness direction. In this embodiment, the protrusion height of the gasket 29 is the same between the narrow portion 33 and the wide portion 31 in the free state. However, this protrusion height can also be made larger or smaller for the narrow portion 33 than for the wide portion 31.

[0057] In this embodiment, the projection 37 is integrally provided with the cover 19. Specifically, the projection 37 is formed by drawing or pressing the cover 19 to cause a portion corresponding to the narrow portion 33 to protrude in the thickness direction toward the inner surface 19b. The inner surface 19b is located inside the housing 3 when the cover 19 is attached to the base 17. The outer surface 19c is located outside the housing 3 when the cover 19 is attached to the base 17.

[0058] The projection 37 may be formed separately from the cover 19 and then fixed to the cover 19. The fixing method can be any appropriate method, such as adhesive bonding or welding. When the projection 37 is integrated with the cover 19, it has barrier properties equal to or better than those of the gasket 29. When the projection 37 is separate from the cover 19, it is preferable that it has barrier properties equal to or better than those of the gasket 29.

[0059] In this embodiment, the projection 37 has an end portion 37a in the extension direction located within the transition portion 35. The height of the end portion 37a gradually increases in the thickness direction from the wide portion 31 side to the narrow portion 33 side in the extension direction. By providing the transition portion 35 in accordance with this end portion 37a, the gasket 29 can be smoothly transitioned from the wide portion 31 to the narrow portion 33 while suppressing fluctuations in the protruding height. This ensures the airtightness of the gasket 29.

[0060] The gradual increase in the height of the end portion 37a means that the height increases continuously or in steps. In this embodiment, the height of the end portion 37a increases continuously in an inclined manner, but the shape can be arbitrarily set.

[0061] For example, the height of end 37a may increase in a parabolic shape. Alternatively, the height may gradually increase, resulting in a shape where multiple parts with continuously increasing heights are connected at a point of constant height, or a shape where multiple parts with constant but different heights are connected.

[0062] The main body portion 37b between the ends 37a of the projection portion 37 is flat and has a constant height in the thickness direction. The height of this main body portion 37b defines the height of the projection portion 37 in the thickness direction. Preferably, the height of the projection portion 37 in the thickness direction is greater than 0 and less than twice the height difference (difference in thickness direction) between the narrow portion 33 and the wide portion 31 in the free state. More preferably, the height of the main body portion 37b is 0.5 to 1.5 times the height difference between the narrow portion 33 and the wide portion 31 in the free state. This is because it is preferable to suppress fluctuations in the height between the narrow portion 33 and the wide portion 31 in order to ensure the airtightness of the gasket 29. In this embodiment, the height of the projection portion 37 is less than the plate thickness of the cover 19 and is the same as the height difference between the narrow portion 33 and the wide portion 31.

[0063] The main body portion 37b maintains a high degree of flatness due to the effect of the ribs. By positioning the narrow portion 33 of the gasket 29 on this highly flat main body portion 37b, it is possible to further improve the airtightness.

[0064] The widthwise end portion 37c of the projection 37, like the end portion 37a, gradually increases in height from both sides in the widthwise direction toward the main body portion 37b. In this embodiment, the height of the end portion 37c increases continuously in an inclined manner, but like the end portion 37a, its shape can be arbitrarily set.

[0065] [Manufacturing of recording devices] The recording device 1 of this embodiment is manufactured by attaching a cover 19 to the base 17 of the housing 3 which houses the internal mechanism 5 including the disk 7, thereby closing the space 3a of the housing 3 which houses the disk 7.

[0066] In other words, the cover 19 with the gasket 29 attached is positioned facing the opening 17a of the base 17 in the thickness direction. In this state, the cover 19 and the base 17 are brought close to each other, and the tip of the gasket 29 is brought into contact with the cover receiving portion 25 of the base 17.

[0067] When the cover 19 and base 17 are brought closer together, the gasket 29 is compressed between the cover 19 and the base 17. In this embodiment, the protruding height of the gasket 29 at the narrow portion 33 is increased by the rise provided by the projection 37. As a result, the compression ratio of the gasket 29 at the narrow portion 33 is increased. Consequently, the gasket 29 is sufficiently compressed not only at the wide portion 31 but also at the narrow portion 33, improving the overall airtightness.

[0068] Furthermore, since the height of the projection 37 is less than twice the height difference between the narrow portion 33 and the wide portion 31, it suppresses height fluctuations between the narrow portion 33 and the wide portion 31, thereby further ensuring the airtightness of the gasket 29. In particular, in this embodiment, the height of the projection 37 is set to be the same as the height difference between the narrow portion 33 and the wide portion 31, and the protruding height of the gasket 29 is the same between the narrow portion 33 and the wide portion 31. As a result, the tip of the gasket 29 in the thickness direction is smooth between the narrow portion 33 and the wide portion 31. Consequently, the airtightness of the gasket 29 is reliably improved.

[0069] Furthermore, in this embodiment, the transition section 35 between the narrow section 33 and the wide section 31 gradually decreases in height toward the narrow section 33. On the other hand, the end portion 37a of the projection 37 is located within the transition section 35, and its height gradually increases toward the narrow section 33. As a result, fluctuations in the protruding height of the gasket 29 are more reliably suppressed, improving the sealing performance.

[0070] Figure 8 is a cross-sectional view showing the area around the narrow portion of the gasket 29, relating to a modified example of Embodiment 1 of the present invention.

[0071] In the modified example shown in Figure 8, the projection 37 is the part that is sheared when it punches through the outer casing 39 of the cover 19.

[0072] Before shearing, the projection 37 is integrally continuous with the connecting portion 41, spanning the portion that will become the outer casing 39, and together with the connecting portion 41, it forms a rib shape. The connecting portion 41 refers to the portion that partially connects the outer casing 39 of the cover 19 to a frame or the like outside the product. When the projection 37 is sheared relative to the connecting portion 41, a corner portion 43c is provided by preventing sagging between the surface 43a and the fracture surface 43b according to the shearing direction. The shearing direction is from the outer surface 19c of the cover 19 toward the inner surface 19b.

[0073] In this modified form, the gasket 29 can be positioned closer to the corner 43c on the projection 37, which can accommodate space constraints. [Examples]

[0074] Figure 9(A) is a longitudinal cross-sectional view showing the area around the narrow portion of the gasket according to Embodiment 2 of the present invention, and Figure 9(B) is a longitudinal cross-sectional view showing the cover of Figure 9(A) before it is attached to the base. Figure 10 is a transverse cross-sectional view along line XX in Figure 9(A). In Embodiment 2, the basic configuration is the same as that of Embodiment 1, so the same reference numerals are used for corresponding components, and redundant explanations are omitted. The longitudinal cross-section in Figure 9(A) is a cross-section along the extension direction of the gasket.

[0075] In this embodiment, the projection 37 is provided on the base 17 instead of the cover 19.

[0076] The projection 37 is integrally formed with respect to the base 17 by pressing, cutting, or the like in the portion corresponding to the narrow portion 33. The portion corresponding to the narrow portion 33 refers to the portion that faces the narrow portion 33 in the thickness direction when the cover 19 is attached to the base 17. The projection 37 may also be formed separately from the base 17 and fixed by welding, adhesive, or the like.

[0077] The projection 37 is formed as a solid convex ridge in a longitudinal cross-section along the extension direction. The end portion 37a of the projection 37 in the extension direction has a gradually increasing height in the thickness direction from the portion on the wider portion 31 side to the portion on the narrower portion 33 side. The end portion 37a may also be formed as a surface along the thickness direction.

[0078] In a cross-section perpendicular to the extension direction, the height of the projection 37 increases gradually from both sides in the width direction toward the main body 37b, even at the end 37c in the width direction. The end 37c may also be formed from a surface along the thickness direction.

[0079] The height of the main body portion 37b of the projection 37 is the same as the height difference between the wide portion 31 and the narrow portion 33. This increases the compression ratio of the narrow portion 33. The height of the main body portion 37b of the projection 37 may be greater than or less than the height difference between the wide portion 31 and the narrow portion 33. In the vertical cross-section of Figure 9(B), if the shape of the projection 37 does not match the shape of the recess 29a formed by the narrow portion 33, the gap between the projection 37 and the recess 29a is filled by the deformation of the gasket 29. This gap setting also allows for adjustment of the compression ratio of the wide portion 31 and the narrow portion 33.

[0080] The width of the main body portion 37b of the projection 37 is greater than the width of the narrow portion 33 and less than the width of the wide portion 31. However, the width of the main body portion 37b of the projection 37 can be the same as or smaller than the width of the narrow portion 33.

[0081] Figures 11(A) to (C) relate to a modified example of Embodiment 2 and are cross-sectional views showing the area around the narrow portion 33 of the gasket 29. Note that the cross-sections in Figures 11(A) to (C) are cross-sections in a direction perpendicular to the extension direction.

[0082] In the modified example shown in Figure 11(A), the width of the main body portion 37b of the projection 37 is made smaller than the width of the narrow portion 33. The projection 37 bites into the narrow portion 33 in the width direction at its center, making it difficult for the narrow portion 33 to shift relative to the projection 37.

[0083] The modified examples in Figures 11(B) and (C) show that the narrow portion 33 and the projection 37 of the gasket 29 are eccentric in the width direction. Here, eccentricity refers to the displacement in the width direction between the center of the narrow portion 33 and the center of the projection 37 in the width direction in a cross-section perpendicular to the extension direction of the gasket 29.

[0084] In the modified examples shown in Figures 11(B) and (C), the projection 37 is formed to be smaller in the width direction than the narrow portion 33. The projection 37 bites into the inside of the narrow portion 33 in the width direction, making it difficult for the narrow portion 33 to shift inward in the width direction of the gasket 29 relative to the projection 37.

[0085] In Figure 11(B), the projection 37 is positioned offset outward from the inner edge of the cover receiving portion 25 of the base 17, while in Figure 11(C), the projection 37 is positioned on the inner edge of the cover receiving portion 25 of the base 17. The configurations in Figures 11(A) to (C) can also be applied to the projection 37 provided on the cover 19 of Embodiment 1.

[0086] In this Example 2 and its modified form, the same effects and advantages as in Example 1 can be achieved. [Examples]

[0087] Figure 12 is a longitudinal cross-sectional view showing the area around the narrow portion of the gasket according to Embodiment 3 of the present invention. Since Embodiment 3 shares the same basic configuration as Embodiment 1, the same reference numerals are used for corresponding components, and redundant explanations are omitted.

[0088] In this embodiment, the protrusions 37A and 37B are provided on the cover 19 and the base 17, respectively.

[0089] The projection 37A is configured in the same manner as in Example 1, and the projection 37B is configured in the same manner as in Example 2. Note that the projections 37A and 37B may have the same cross-sectional shape.

[0090] The narrow portion 33 is formed with a height in the thickness direction that is even smaller than that of Examples 1 and 2, and as a result, its width is also formed to be even smaller than that of Examples 1 and 2. Otherwise, it is the same as in Example 1. The tip of the narrow portion 33 in the thickness direction may be either a form in which it transitions flatly from the wide portion 31, as in Example 1, or a form in which it has a recess 29a, as in Example 2.

[0091] In this embodiment 3, in addition to achieving the same effects as in embodiments 1 and 2, the width of the narrow portion 33 can be made even smaller, allowing it to be used in even narrower spaces. [Examples]

[0092] Figure 13 is a bottom view of the cover showing the area around the narrow portion of the gasket according to Embodiment 4 of the present invention. Since Embodiment 4 has the same basic configuration as Embodiment 1, the same reference numerals are used for corresponding components, and redundant explanations are omitted.

[0093] In this embodiment, the narrow portion 33 is offset in the width direction relative to the wide portion 31. Accordingly, the shape of the transition portion 35 has been changed compared to Embodiment 1.

[0094] The narrow section 33 is eccentric, so that its outer edge in the width direction coincides with the outer edge of the wide section 31. The amount of eccentricity can be set as appropriate, and the outer edge of the narrow section 33 and the outer edge of the wide section 31 do not necessarily coincide. The transition section 35 is designed so that only its inner edge in the width direction is inclined, causing the width to gradually decrease.

[0095] Even in this configuration of Embodiment 4, the same effects and advantages as in Embodiment 1 can be achieved. Furthermore, the eccentricity between the narrow portion 33 and the wide portion 31 suppresses inward protrusion in the width direction when the gasket 29 is compressed. [Explanation of Symbols]

[0096] 1. Recording device 3a Space part 5 Internal mechanism 17 Bass 17a opening 19 Cover 19a Outer periphery 29 Gasket 31 Large portion 33 Narrow width section 35 Transition section 37 Protrusion 37a end

Claims

1. A base that houses the internal mechanism within a space having an opening, A cover attached to the opening of the base to close the space, The cover comprises a gasket that extends circumferentially along the outer circumference and is compressed by contact with the base, The gasket comprises a wide portion with a relatively large width extending inward and outward along the circumferential shape, and a narrow portion with a relatively small width. The cover and the base, or one or both, are provided with a projection in the compression direction of the gasket in the portion corresponding to the narrow portion, which increases the compression ratio of the narrow portion. Recording device.

2. A recording device according to claim 1, The gasket has a transition portion between the wide portion and the narrow portion, where the height in the compression direction gradually decreases from the wide portion to the narrow portion. Recording device.

3. A recording device according to claim 2, The aforementioned projection is provided on the cover, Recording device.

4. A recording device according to claim 3, The end of the projection in the extending direction of the gasket is located within the transition portion, and the height in the compression direction gradually increases from the wider portion in the extending direction to the narrower portion in the extending direction. Recording device.

5. A recording device according to claim 2, The aforementioned projection is provided on the base, Recording device.

6. A recording device according to any one of claims 1 to 5, The narrow portion and the wide portion are eccentric in the width direction of the gasket. Recording device.

7. A recording device according to any one of claims 1 to 5, The aforementioned projection is formed to be smaller than the narrow portion in the width direction of the gasket. The aforementioned projection and the aforementioned narrow portion are eccentric in the width direction. Recording device.

8. A cover that is attached to an opening in a base that houses an internal mechanism within a space and closes the space, The outer periphery that is supported by the base, The gasket extends in a circumferential manner along the outer circumference and is compressed by contact with the base, The gasket comprises a wide portion with a relatively large width extending inward and outward along the circumferential shape, and a narrow portion with a relatively small width. The outer periphery is provided with a projection in the compression direction of the gasket that increases the compression ratio of the narrow portion, in the portion corresponding to the narrow portion. cover.

9. The cover according to claim 8, The gasket has a transition portion between the wide portion and the narrow portion, where the height in the compression direction gradually decreases from the wide portion to the narrow portion. cover.

10. The cover according to claim 9, The end of the projection in the extending direction of the gasket is located within the transition portion, and the height in the compression direction gradually increases from the wider portion in the extending direction to the narrower portion in the extending direction. cover.

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