JPS6315675Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention is intended to reduce noise from blowers in ventilation systems of factories, buildings, subways, public ditches, etc.
The present invention relates to a silencer unit that is installed in the middle of a duct, tunnel, etc., or at an opening to prevent the propagation of indoor and outdoor noise, and is formed singly or in combination.

[Conventional technology]

As mufflers conventionally used in air supply/exhaust equipment, there are sound absorbing mufflers such as internal burr mufflers, cell mufflers, and splitter mufflers. For example, in an example of a conventional cell-type silencer shown in FIG. 1, a sound absorbing material 3 such as glass wool is filled between an outer casing 1 made of a perforated or non-perforated plate and an inner casing 2 made of a perforated plate. Then, rivet 5 the cap 4 on both ends of the outer and inner casings 1 and 2.
It is fixed and formed by etc. As the sound absorbing material 3, materials made of inorganic fibers such as rock wool are also used.

[Problem that the invention attempts to solve]

However, the sound absorbing material 3 made of inorganic fiber has a high water absorbing property, so once water is absorbed, the sound absorbing performance deteriorates over a long period of time.
Further, since the mechanical strength is low, an inner casing 2 such as a perforated plate or a surface protection material such as glass cloth 6 is required.

In addition, when the internal casing 2 made of a perforated plate increases the wind speed inside the cell, the scraping sound becomes louder and the noise reduction effect is impaired.

The present invention eliminates the above-mentioned problems of the conventional one.
To provide a silencer unit which has low water absorption, does not particularly require a surface protection material, and does not use a perforated plate, so that it does not generate a large scraping sound even when high-speed gas passes through it. This is the purpose.

[Means for solving problems]

In the present invention, bent portions parallel to the axis of the cylindrical body in a longitudinal section are formed at both ends of a cylindrical body formed of a sintered aluminum sound-absorbing plate and open at both ends at a predetermined distance from the surface of the cylindrical body. This is a silencer unit characterized by being formed by fixing flanges that are held apart.

[Effect]

Since the present invention uses a cylindrical aluminum sintered sound absorbing plate, its water absorption is small, so there is no reduction in sound absorption performance due to water absorption. Furthermore, since the mechanical strength is high, no surface protection material is required. Furthermore, since the surface is smooth and the surface unevenness is not large like that of a perforated plate, the scraping noise is also small.

By the way, the sound absorption characteristics of this muffler unit can be changed by changing the thickness of the air layer outside the cylindrical body. Therefore, since the silencer unit of the present invention is formed by attaching flanges having bent parts to both ends of a cylindrical body, it can be simply inserted and fixed into the external casing as shown in Fig. 4, or as shown in Fig. 5. By simply connecting the muffler units in this manner, an air layer of a predetermined thickness can be reliably formed and maintained between the cylindrical body and the outer casing or between the muffler units, thereby achieving the desired sound absorption characteristics. It can be made to stand. In addition, for example, attachment of the external casing and connection of the muffler units to each other can be easily carried out by using the bends.

〔Example〕

The present invention will be described with reference to the drawings. In FIG. 2, reference numeral 7 denotes a cylindrical body with openings at both ends formed from a porous sintered aluminum sound absorbing plate made of sintered aluminum powder. It may be integrally formed into a cylindrical or rectangular tube shape, but in the case of a rectangular, square or other polygonal cross section, flat plates may be combined.
As shown in FIG. 3, flanges are provided at both ends of the cylindrical body 7 to hold a bent portion 8 parallel to the axis of the cylindrical body 7 in a longitudinal section at a predetermined distance l from the surface of the cylindrical body 7. 9 are fixed by rivets 5. In addition to this, various methods such as welding and caulking can be used to fix the flange 9.

The flange 9 is used, for example, to secure an air layer outside the cylindrical body 7 when inserting this muffler unit into an external casing, and the sound absorption characteristics can be changed by arbitrarily setting the distance l. can be set. For example, by increasing the distance l, sound absorption characteristics in the low frequency region can be improved. In this case, the bent portion 8 can reliably maintain an air layer with a thickness of distance l, and can be easily attached.

As shown in FIG. 4, by bending the outer peripheral end of the flange 9 outward to provide a bent portion 8, the external casing 1 and other silencer units can be connected to each other.
This can be done using rivets or the like.

As shown in Fig. 5, a plurality of silencer units are
If they are directly connected at the flange 9 and connected vertically and horizontally in the cross section, part of the external casing can be omitted.

[Effect of idea]

By using the aluminum sintered sound-absorbing plate in this way, the present invention not only has a good sound-absorbing effect, but also
Since it does not absorb water, there is no reduction in sound absorption performance due to water absorption. In addition, the mechanical strength is greater than that of inorganic fibers, so there is no need for surface protection materials such as perforated plates or glass cloth.Furthermore, the surface is smooth, so there is little scraping noise, and the sound reduction effect due to airflow does not deteriorate. . It is also lighter than porous magnetic sound absorbing materials. In addition, by attaching flanges with bent portions to both ends of the cylindrical body, an air layer of a predetermined thickness can be reliably formed on the outside of the cylindrical body by simply inserting and fixing the muffler unit into the external casing, for example. For example, it is easy to attach the units to the external casing and connect the units to each other, and when connecting a plurality of units vertically or horizontally, a part of the external casing can be omitted.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the conventional example, Figures 2 to 5
The figure shows an embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view,
FIG. 3 is a detailed view of part A, FIG. 4 is a longitudinal sectional view of another embodiment, and FIG. 5 is a longitudinal sectional view of an embodiment using a plurality of units. DESCRIPTION OF SYMBOLS 1... External casing, 2... Inner casing, 3... Sound absorbing plate, 4... Cap, 5... Rivet, 6... Glass cloth, 7... Cylindrical body, 8...
...Bent part, 9...Flange.

Claims (1)

[Scope of utility model registration request] Bent parts parallel to the axis of the cylindrical body in a longitudinal section are held at both ends of a cylindrical body formed of a sintered aluminum sound-absorbing plate and open at both ends at a predetermined distance from the surface of the cylindrical body. A silencer unit characterized by a fixed flange.