JP2605727Y2 - Soundproof structure at the side of the cover - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof structure of a printer or other office equipment used as an output device of an electronic computer, and in particular, to a noise leaking from a mating side of a cover covering an opening provided in a housing. It relates to the structure to prevent.

[0002]

2. Description of the Related Art An opening for operation is provided in a housing of office equipment. For example, in a printer used as an output device of an electronic computer, openings for exchanging an ink ribbon and an ink cartridge are provided, and these openings are closed with a cover in a normal use state. Although the housings and covers of these devices also have a role in preventing noise inside the device from leaking out of the device, noise often leaks from joints of the covers. Therefore, in order to prevent noise from leaking from the joint of this cover, a structure in which the joint is closely attached with a clamp tool or a structure in which a sound absorbing material such as felt is attached to the contact surface of the joint has been adopted. .

[0003]

However, the structure in which the fitting sides of the cover are brought into close contact with the clamp tool complicates the operation of opening and closing the cover, and also complicates the structure of the cover and increases the equipment cost. In addition, the structure in which a sound absorbing material such as felt is stuck requires a lot of trouble in manufacturing a housing and a cover, and also has a problem in durability of the sound absorbing material when used for many years. However, in the structure shown in FIG. 3A, in which the mating sides of the covers are merely overlapped so as to abut each other, when a gap is formed in the mating portion due to a molding error or the like, noise leakage from the gap is large, There is a problem that the sound insulation function of the cover is significantly reduced.

The present invention has been made to solve the above-mentioned problem, without complicating the structure and opening / closing operation of the cover, and even when a gap is formed on the mating side due to molding or assembly errors. It is an object of the present invention to obtain a soundproof structure that can reduce noise leaking from a gap as much as possible.

[0005]

According to the structure of the present invention, the cover 4 is closed in a state where the mating side of the cover 4 overlaps with the mating side of the counterpart, and the opposing strip-shaped mating surfaces 12 and 13 have the sides. The above problem is solved by providing a plurality of protrusions 6, 7 inserted into the concave grooves 8, 9 on the other side in a direction parallel to the direction. The protrusions 6 and 7 and the concave grooves 8 and 9 are formed at the same time when the cover 4 and the housing 2 are formed.

[0006]

According to the above structure, even when a gap 11 is formed between the mating surfaces 12 and 13 of the cover 4 due to a molding error or an assembly error, the path length of the gap 11 from the inside of the apparatus to the outside of the apparatus is reduced. Long and the path is bent, the clearance 11
The noise leaking from the vehicle can be greatly reduced. Also, ridges 6 and 7 and concave grooves 8 and 9 for forming this bent long path are provided.
Can be formed at the same time when the cover 4 and the housing 2 are formed, so that the cost of the cover 4 and the housing 2 rises very little. Further, the ridges 6 and 7 may be provided so as to protrude in the opening and closing direction of the cover 4.
The opening and closing operation of the cover 4 does not become complicated due to the provision of.

[0007]

1 and 2 show an embodiment of the present invention. The apparatus 1 in the illustrated embodiment is a desktop printer.
An opening 3 for exchanging the ink ribbon cassette is provided at an upper portion of the housing 2 of the apparatus, and a cover 4 is provided to cover the opening during normal use. The cover 4 is located at the back 5
The engagement between the projections and the holes at both side ends of the side makes it possible to rotate around the back side 5 and open and close. Lower surfaces of both sides and the front side of the cover 4 (the mating surface 12) and upper surfaces of both sides of the periphery of the opening 3 and the front side (the mating surface 1).
3) includes a plurality of ridges 6, 7 in a direction parallel to these sides.
And concave grooves 8 and 9 are formed.

FIG. 1 is an enlarged sectional view of a portion in which the ridges 6 and 7 and the concave grooves 8 and 9 are formed. In the embodiment shown in the figure, four ridges 6 and three Are formed on the cover side of the housing 2 and the four ridges 7 and the three
Are formed. The cover 4 is closed with the three ridges 6 and 7 inserted into the concave grooves 8 and 9 on the other side. The direction of movement of the cover 4 during opening and closing is the direction in which the protrusions 6 and 7 protrude, and the cover-side protrusion 6 and the housing-side protrusion 7 do not interfere with each other when the cover 4 is opened and closed.

FIG. 1 shows the closed state with a gap 11 left between the ridges 6 and the grooves 8 of the cover and the ridges 7 and the grooves 9 of the housing. The dimensions of the ridges 6 and 7 and the grooves 8 and 9 are determined so as to fit as closely as possible. In the illustrated embodiment, the cross sections of the ridges 6 and 7 and the concave grooves 8 and 9 are rectangular, but the ridges 6 and 7 and the concave grooves 8 and 9 are trapezoidal in which the tip side and the bottom side are narrow. It can be a cross section.

[0010] Table 1 shows the test results obtained by measuring the amount of noise leakage between the structure of the present invention and the conventional structure. A speaker was placed in a box made of acrylic resin, and FIGS. 3 (a) and 3 (b).
Then, the sound pressure of the speaker outside the box was measured with a standard condenser microphone.

[0011]

[Table 1]

FIG. 3A shows a conventional structure in which the mating sides of the cover are closed with a Z-shaped butt structure, and a gap of 0.5 mm is formed at the butt end. The structure shown in FIG. 3B is the structure of the present invention shown in the above embodiment, and the protrusions 6 and 7 and the grooves 8 and 9 which fit into each other.
And a gap of 0.5 mm was formed between them. The plate thickness of the cover 4 in FIG. 3A is 4 mm, and the width of the fitting portion in FIG. 3B is 25 mm. As shown in Table 1, the result of the noise measurement was 46.0 dB for the conventional structure (a), but 42.5 dB for the structure (b) of the present invention.
It is a decibel, and it was confirmed that the structure of the present invention has excellent sound insulation performance when a gap is formed at the mating side of the cover.

[0013]

According to the structure of the invention described above,
When a gap is formed on the mating side when the cover is closed due to a molding error or an assembly error of the cover or the housing, noise leaking from the gap can be reduced as much as possible. The structure of the present invention does not increase the man-hours and assembly man-hours of the housing and the cover, and does not complicate the operation of the operator when opening and closing the cover.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a main part of the present invention.

FIG. 2 is a schematic perspective view showing an example of a device provided with the soundproof structure of the present invention.

FIG. 3 is a cross-sectional view showing a gap used for a test of sound insulation performance.

[Explanation of symbols]

 2 housing 4 cover 6 ridge 7 ridge 8 concave groove 9 concave groove 11 gap 12 mating surface 13 mating surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G10K 11/16-11/178 B41J 29/08 H05K 5/00-5/06

Claims (1)

(57) [Scope of request for utility model registration] The cover (4) is closed in a state where the mating side of the cover (4) overlaps with the mating side of the periphery of the opening (3) closed by the cover, and the opposing strip-shaped mating surfaces (12, 13) A soundproof structure on a mating side of a cover, comprising a plurality of ridges (6, 7) inserted into concave grooves (8, 9) on the other side in a direction parallel to the mating side.