JP3346881B2 - Office automation equipment silencer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction device for office automation equipment, and more particularly to a noise reduction device for a noise reduction cover for preventing noise generated inside office automation equipment from leaking to the outside.

[0002]

2. Description of the Related Art Noise prevention and silencing of office automation equipment in the past have mainly focused on passive measures using sound absorbing and sound insulating materials. In addition, there is an active countermeasure against this, for example, active noise control (Active Noise).
In Control, a sound having an opposite phase is intentionally emitted, and noise is eliminated by interference. Although the concept of active noise control has been around for a long time, advanced noise control technology was required to apply it to actual products, and the realization of active noise control was delayed due to its restrictions. It became possible with the development of signal processing technology. The good point of the active noise control is that the noise reduction effect is large even at a low frequency where the effect of the sound absorbing / insulating material is small. Famous examples of such active noise controls include those applied to refrigerators and automobiles, which use speakers or the like to produce sounds in opposite phase to noise, The sound is canceled by interfering with the sound. Further, as an example of a silencer to which the principle of the Helmholtz resonator is applied, there is a system described in Japanese Patent Application Laid-Open No. 4-469. In this method, the mouth of a hollow silencer is connected to a soundproof cover that encloses a gear unit provided adjacent to a developing unit of a laser printer device. The frequency of the natural frequency is reduced.

[0003]

Generally, the operating noise generated by OA equipment used in an office such as a copying machine causes noise, which hinders a comfortable office environment, and becomes a problem particularly in a sound environment. In order to minimize the noise from leaking to the outside of the OA device, it is desirable to surround the OA device with exterior parts or the like. However, for a copying machine or the like, an opening for discharging a sheet to the outside and an opening for taking in / out cooling air to avoid a rise in temperature inside the apparatus are indispensable. For these reasons, there is a limit to silencing simply by surrounding the equipment.
In view of the above, an object of the present invention is to provide a noise reduction device that reduces leakage of sound waves from a cooling device to the outside and does not hinder the flow of air.

[0004]

In [SUMMARY OF] of claim 1 the invention, in the noise suppressor of the office automation equipment to not leak the noise generated by the internal auto <br/> office automation equipment to the outside, the muffler is The office automation device is provided on an exterior cover of the office automation device having an opening at a portion where a cooling fan is provided, and has a predetermined length and width in a plane direction of the exterior cover, and in a direction perpendicular to this. A guide plate having a predetermined thickness is provided, and a curved guide plate is provided in the exhaust direction of the opening of the exterior cover from the cooling fan.

According to a second aspect of the present invention, there is provided a silencer for an office automation device for preventing noise generated inside the office automation device from leaking to the outside, wherein the silencer includes a portion having a cooling fan of the office automation device. the provided outer cover of the office automation equipment having an opening, said and having a predetermined length and width in the plane direction of the outer cover consists of a cover having a predetermined thickness in a direction perpendicular thereto, wherein A guide plate having a curved surface provided in a direction in which the opening of the exterior cover is exhausted from the cooling fan and a closed end side of the cover provided in the exterior cover
A curved guide plate is further provided between the curved guide plate and the curved guide plate.

[0006]

According to the first aspect of the present invention, the opening of the outer cover is performed.
Since the curved guide plate is provided in the direction of exhaust from the cooling fan at the mouth , vortex flow of air at the lower portion of the fan is eliminated, and air resistance is reduced and fluid noise is reduced.

According to the second aspect of the present invention, the outer cover is provided.
Guide plate having a curved surface provided in the exhaust direction from the cooling fan at the opening of the cover and a cover provided on the exterior cover
Since the curved guide plate is further provided between the curved guide plate provided on the closed end side of the fan, the flow rectifying effect of the fan is enhanced, and the air resistance and the fluid noise are reduced.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a muffler for office automation equipment to which the present invention is applied. As shown in FIG. 1, an exterior cover 1 having an opening for a cooling fan 2 is provided with a partially open enclosure, and a sound absorbing material such as a foaming material or glass wool is attached to the inner wall of the outer cover 1. While maintaining the flow of air, a muffling unit that effectively attenuates sound waves radiated to the outside can be formed. It is well known that the frequency of a sound wave that can be absorbed by the sound absorbing material or the like is a frequency of about 1 Kz or higher. However, noise generated by a cooling fan often used in a copying machine or the like has a noise level at which the frequency component around several hundred Hz generated by the number of fan blades × rotational speed is the largest. Further, the frequency of the main noise caused by the engagement of a certain gear for driving the copying machine is also around several hundred Hz. Therefore, in the case of an OA device such as a copying machine, it is impossible to reduce main noise in a frequency band of several hundred Hz or less with the silencer shown in FIG. Therefore, in the present invention, in order to realize a noise-reducing outer cover having a silencer capable of effectively reducing noise in a frequency band of several hundred Hz or less without disturbing air flow as much as possible. , A curved guide plate is provided on the outer cover, and silencing using interference of opposite-phase sound, and a shape using the Helmholtz resonator theory,
And the mechanism.

A length L and a width W are provided on the exterior cover 1 having the opening 7 of the cooling fan 2 in the in-plane direction of the exterior cover 1.
A second exterior cover having a space having a thickness T in a direction perpendicular to the second exterior cover is provided. The silencer 3 is open only to one side in the longitudinal direction (opening 9 of the silencer 3), and air flows into and out of the device through this portion. The distance from the center of the opening 7 of the fan 2 to the closed end opposite to the muffler opening 9 is d.
And Basically, a structure in which a part of the silencer 3 having such a structure is formed into a curved surface will be described below. FIG. 2 shows an example of a sound deadening device in which a closed end portion 4 at an upper portion of a fan 2 provided on a part of an exterior cover 1 has a curved surface shape. By forming the closed end 4 into a curved shape as shown in the figure, air resistance is reduced and fluid noise can be prevented. That is, in a silencer of an office automation device including an exterior cover of an office automation device and a fan and a silencer disposed in a part of the exterior cover, a closed end of the silencer has a curved surface portion. .

Next, one configuration example will be described with reference to FIG. A curved guide plate 5 is inserted into an upper portion (closed end side of the muffler) of the fan 2 provided in a part of the outer cover 1. By inserting the curved guide plate 5 above the fan 2, the air vortex (confirmed in the video of the visualization experiment with smoke) seen at the closed end 4 of the silencer 3 is eliminated, and the air resistance is reduced. Also, fluid noise is reduced. Thus, the outer cover 1 on the top of the fan (closed end of the silencer)
In this configuration example, a curved guide plate 5 is inserted into the fin to reduce air resistance and reduce fluid noise.

The invention described in claim 1 will be described based on the embodiment shown in FIG. A curved guide plate 6 is inserted into the exterior cover 1 below the fan 2 (on the opening side of the silencer). By inserting the curved guide plate 6 under the fan 2, the vortex of air (confirmed in the video of the visualization experiment with smoke) seen at the bottom of the fan 2 is eliminated, the air resistance is reduced, and the fluid noise is also reduced. I do. In this way, the curved guide plate 6 is inserted into the exterior cover 1 (opening side of the silencer) at the lower part of the fan to reduce the air resistance and reduce the fluid noise. It is the described invention.

The second aspect of the present invention will be described with reference to FIG. FIG. 5 shows a silencer 3 in which a curved guide plate 5 is inserted above and below the fan 2 of the exterior cover 1 and between them. By providing a curved guide plate 8 between these guide plates 5 in addition to the upper and lower curved guide plates 5 of the fan 2, the rectification effect is enhanced, and the fan 2
Power consumption and fluid noise can be further reduced. This is the second aspect of the present invention.

[0013]

According to the first aspect of the present invention, the use of a curved guide plate in the lower part of the fan eliminates the vortex flow of air in the lower part of the fan, thereby reducing air resistance and fluid noise. .

According to the second aspect of the present invention, by inserting a curved guide plate between the upper and lower portions of the fan, the flow rectifying effect of the fan is enhanced, and air resistance and fluid noise can be reduced. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a muffling device such as an office automation device to which the present invention is applied.

FIG. 2 is a diagram showing a modified example thereof.

FIG. 3 is a diagram showing one configuration example of the present invention.

FIG. 4 is a diagram showing an embodiment of the invention described in claim 1;

FIG. 5 is a diagram showing an embodiment of the invention described in claim 2;

Continuation of the front page (56) References JP-A-4-78871 (JP, A) JP-A-62-70789 (JP, A) JP-A-62-253998 (JP, A) JP-A-3-94278 (JP) , A) JP-A-61-85521 (JP, A) JP-A-2-93554 (JP, A) Full-open Japanese Utility Model Application No. 61-12094 (JP, U) Japanese-Japanese Utility Model Laid-Open No. 4-24757 (JP, U) 64-48535 (JP, U) Japanese Utility Model 62-143957 (JP, U) Japanese Utility Model Application Hei 2-56492 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/00 550 G03G 21/00 530 G03G 21/16 B41J 29/08 G10K 11/00-11/36

Claims (2)

(57) [Claims] 1. A silencer for an office automation device for preventing noise generated inside the office automation device from leaking to the outside, wherein the silencer includes:
The office automation device is provided on an exterior cover of the office automation device having an opening at a portion where a cooling fan is provided, and has a predetermined length and width in a plane direction of the exterior cover, and in a direction perpendicular to this. consists cover having a predetermined thickness, the outer cover
A silencer for an office automation device, wherein a guide plate having a curved surface is provided in a direction in which the opening of the cooling fan is exhausted from the cooling fan. 2. A muffler for an office automation device for preventing noise generated inside the office automation device from leaking to the outside, wherein the muffler includes:
The office automation device is provided on an exterior cover of the office automation device having an opening at a portion where a cooling fan is provided, and has a predetermined length and width in a plane direction of the exterior cover, and in a direction perpendicular to this. consists cover having a predetermined thickness, the outer cover
The guide plate and the outer cover having a curved surface shape that was kicked set <br/> the exhaust direction from the cooling fan of the opening of the over
Curved surface provided on the closed end side of the provided cover
A silencer for office automation equipment, further comprising a curved guide plate between the guide plate and the guide plate .