JPS5838916Y2 - Silent air suction device for ventilation ducts - Google Patents

Description

[Detailed explanation of the invention] This invention is such that, for example, a silencer chamber is formed in the air suction device of a ventilation duct having an inlet facing into the room with less pressure loss at the iron part, as shown in Figure 2 below. An example of this invention will be described.

That is, in Fig. 2, 1 is a suction box for ventilation of indoor air with a suction port 2 located on the ceiling surface A, and an opening 3 inside.
A main air chamber 5 and a sub-air chamber 6 are defined by a single partition plate 4 in the center.

7 is an intake port provided on the side wall of the main air chamber 5; 8 is a ceiling fixing bracket for this box attached to the outside of the intake box 1;
9 is a ventilation duct installed in the ceiling, and the duct receiver 10
It is connected to the suction lower of the main air chamber 5 through.

11 is a suction grill attached to the ceiling surface A in an overlapping state so as to cover the front of the suction box 1 and its fixing fittings 8;
It is fixed to the front of the suction box 1 with screws 12, and the inside of the sub-air chamber 6 including this suction grill 11 is connected to the main air chamber 5.
It is constructed to have an almost equal internal volume.

On the other hand, in the conventional suction box of this type, the inside of the suction box 1 is directly connected to the ventilation duct 9, as shown in FIG.
Since the ventilation air blower (not shown) was connected to the ventilation duct 9, the noise from the suction blower (not shown) was transmitted through the ventilation duct 9, passed through the suction box 1, and directly entered the room.

However, in the case of this invention shown in FIG. 2, as described above, the inside of the suction box 1 is divided by the partition plate 4 into an outlet air chamber 5 and an auxiliary air chamber 6 including the suction grille 11, and both of these are separated. Since the internal volumes are set to be approximately equal, the main air chamber 5 functions as a so-called sound-deadening chamber and can effectively eliminate noise transmitted through the ventilation duct 9 and infiltrated by this chamber.

In this case, the auxiliary air chamber 6 is made to have an internal volume equal to that of the main air chamber 5 in order to reduce the pressure loss at the iron part especially when air is sucked in from the room.

For example, when the partition plate 4 is positioned close to the suction grille 11 as shown in FIG. Since a large pressure loss occurs in this part, in order to prevent such inconvenience from occurring, the position of the partition plate is particularly specified as described above.

Therefore, as long as the distance between the partition plate 4 and the suction grille 11 is sufficient and the pressure loss is small, the sizes and internal volumes of the main air chamber 5 and the sub air chamber 6 do not necessarily have to be equal.

The above explanation is based on the case where no sound-absorbing material is specifically used in the main and sub-air chambers 5 and 6, but as shown in FIG. Of course, the silencing effect is further improved.

A main air chamber 5 and a sub air chamber 6 communicating with the ventilation piping 9 are formed in the box 1 at a predetermined distance from the back of the indoor air suction grill 11 provided in the front of the suction box 1. Since one partition plate 4 is provided for the upper and sub-air chambers 5 and 6, there is an advantage that the level of noise entering the room can be reduced without causing an extreme increase in ventilation resistance.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional example of an air suction device for ventilation ducts, Fig. 2 is a cross-sectional view showing an embodiment of the muffling air suction device of this invention, and Fig. 3 is another embodiment of the muffling means. FIG. 4 is an explanatory view of the noise reduction effect. In the figure, 1 is a suction box for indoor air, 4 is a partition plate inside this box, 5 is a main air chamber, 6 is a sub-air chamber, 9 is a ventilation pipe, and 11 is a suction grill for indoor air. In other figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Scope of utility model registration request] (1) Suction port 2 and ventilation duct 9 for sucking indoor air
In a suction box 1 equipped with an intake lower connected to
Attach one partition plate 4 having a
This air suction device for a ventilation duct is characterized by being partitioned into a main air chamber 5 and a sub-air chamber 6. (2) The muffled air suction device for a ventilation duct according to claim 1, wherein the volumes of the main air chamber 5 and the sub-air chamber 6 are made almost equal.