JPS59107128A - Blower provided with damper - Google Patents

Abstract

PURPOSE:To absorb air hissing sound generated when an air current passes though vanes of a damper of a blower, in the interior of a silencer to obtain a noise suppressing effect by providing a butterfly type damper on at an inner part of the discharge silencer or on its upstream side. CONSTITUTION:A butterfly type damper 12 is provided at the inlet part of a discharge silencer 5, and the inclining direction of a valve 12a of the damper 12 is so selected that air from a connecting duct 4 flows uniformly at portions of a bearing 13 supporting both ends of a motor shaft 6a. Accordingly, the air flow from the duct 4 is straightened as shown by arrows 15a, and assumes a flow distribution shown by arrows 15b around the outer periphery of the motor 6. Therefore, air hissing sound generated when air passes the valve plate 12a of the damper 12 is effectively absorbed by a sound absorbent 9 within the silencer 9 before the air hissing sound flows out of the blower.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a blower equipped with a damper whose air volume can be adjusted in a ventilation system, etc., and particularly to a blower damper in a continuous ventilation system such as a train. This relates to a device designed to reduce the

[Prior art]

An example of a conventional blower equipped with a damper is shown in FIG. In the figure, 1 is an impeller provided in a casing 2;
is a suction duct connected to the suction side of the impeller 1; 4 is a connection duct that connects the discharge side of the impeller 1 and the discharge silencer 5; 6 is a motor provided in the discharge silencer 5 and drives the impeller 1. , 7 is a rectifying plate that rectifies the flow from the connecting duct 4, 8 is a suction silencer connected to the upstream side of the suction duct 3, and 9 is a suction silencer 8 and a discharge silencer 5.
Sound absorbing material affixed to the inner surface of the Discharge silencer 5
A slide damper 10 is installed at the outlet of the pump 9, and the required ventilation air volume is adjusted by sliding the valve body 10ae of this damper 10. In the conventional device configured in this way, the rectifying plate 7 was provided inside the discharge silencer 5, so the damper 1o for adjusting the ventilation air volume was provided at the outlet of the discharge side silencer 7 due to the installation space.

For this reason, when the airflow discharged from the impeller 1 passes through the valve body 10a of the damper 10 during operation of the ventilation system, a unique wind noise is generated, and this sound is propagated directly to the outside air, resulting in a large amount of noise. There was a drawback. In addition, the damper 10 had a structure in which the opening degree f of the damper 10 was adjusted by sliding the valve body 10ai, and then fixed at that opening state with bolts, so there was a drawback that adjusting the opening degree of the damper 10 was troublesome. .

FIG. 2 is a diagram illustrating the flow inside the discharge silencer 5 of the blower shown in FIG. 1. Since the flow from the connecting duct 4 flows along the outer wall surface 4a of the duct 4, at the inlet of the discharge silencer 5, the flow is biased towards the lower half side as shown by the arrow 11a. Therefore, the flow is rectified by the rectifying plate 7, and the motor 6 is cooled as an averaged flow as shown by the arrow 11b. As described above, the conventional type requires the current plate 7 and also has the disadvantage that the pressure loss caused by the current plate 7 is large.

[Purpose of the invention]

An object of the present invention is to improve the above-mentioned conventional drawbacks and to provide an entire blower equipped with a low-noise damper that can absorb wind noise generated from the damper of the blower inside the silencer.

[Summary of the invention]

The present invention provides a connection between an impeller provided in a casing, a motor for driving the impeller, a suction duct connected to the suction side of the impeller, and a discharge side of the impeller and a discharge silencer. The blower is characterized in that the motor is provided within the discharge silencer, and a butterfly damper is provided at an inlet portion of the discharge silencer or on its upstream side.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In the figures, parts with the same reference numerals as in FIGS. 1 and 2 are the same parts.

In this embodiment, a butterfly damper 12 is provided at the inlet of the discharge silencer 5. Furthermore, as shown in the figure, the direction of inclination of the valve body 12a of this butterfly damper 12 is selected so that the flow from the connecting duct 4 flows equally to the parts of the bearing 13 that support both ends of the motor shaft 6a. There is.

With the above configuration, the air flow in the blower of the present invention is as follows. When the impeller 1 is driven by the motor 6, air is sucked in from the suction silencer 8 as shown by an arrow 14a, flows as shown by arrows 14b and 14C, is pressurized by the impeller 1, and is discharged through the connecting duct 4. It flows into the eraser 5. The airflow is adjusted to the required ventilation amount by a butterfly damper 11 installed at the inlet of the discharge silencer 5 (on the upstream side of the motor), passes around the outer periphery of the motor 6 inside the discharge silencer as shown by arrow 14d, and moves as shown by arrow 14e. leak to the outside.

The wind noise generated when the butterfly type blower 2 passes through the valve plate 12a1 is effectively absorbed by the sound absorbing material 9 inside the silencer before it flows out of the discharge silencer 5, making it a low-noise blower. can do. The butterfly damper 12 is composed of a valve plate 12a, an arm, a guide (not shown), etc., and the opening degree can be adjusted very easily by rotating the valve plate shaft. According to the present invention, as shown in FIG. 4, the flow from the connecting duct 4 is rectified at the inlet of the discharge silencer 5 by the valve plate 12a of the butterfly damper 12 as shown by the arrow 15a in FIG. , flows around the outer periphery of the motor 6 inside the silencer 5 with a flow distribution as shown by the arrow 15b. Even in the motor 6, the portion of the bearing 13 that supports both ends of the motor shaft 63 generates a large amount of heat, but in the present invention, since a particularly large amount of air flows through the portion of the bearing 13, the bearing 13, which is an important component, can be effectively used. It also has the effect of giving off a cool smell.

In the above embodiment, a butterfly-type damper is installed at the inlet of the discharge silencer, but even if the butterfly-type damper is installed in the upstream side of the discharge silencer, for example, in the suction silencer, the damper will not generate electricity. It is possible to absorb wind noise within the suction silencer or the discharge silencer.

〔Effect of the invention〕

As explained above, according to the blower equipped with the damper of the present invention, since the butterfly type damper is provided at the inlet of the discharge silencer or on the upstream side thereof, when the airflow passes through the damper blades of the blower, It is possible to absorb the wind noise inside the silencer, resulting in a significant noise reduction effect.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a blower equipped with a conventional damper;
The figure is an enlarged cross-sectional view of only the discharge silencer portion in Figure 1, Figure 3 is a longitudinal cross-sectional view showing an embodiment of the blower with a damper according to the present invention, and Figure 4 is the discharge silencer in Figure 3. FIG. 3 is a cross-sectional view showing only a portion enlarged. 1... Impeller base, 2... Casing, 3... Suction duct, 4... Connection duct, 5... Discharge silencer,
6... Motor, 6a... Motor shaft, 12... Butterfly damper, 12a... Valve body, 13... Bearing. Figure 1 q Figure 2 [] Figure 3 Figure 4

Claims (1)

[Claims] 1. An impeller provided in a casing, a motor that drives the impeller, a suction duct connected to the suction side of the impeller, and an outlet side of the impeller and a discharge silencer. A blower equipped with a damper, characterized in that the motor is provided within the discharge silencer, and a butterfly damper is provided at an inlet portion of the discharge silencer or on its upstream side. 2. The inclination direction of the valve body of the butterfly damper is selected so that the flow from the connecting duct does not flow equally to each of the bearing parts supporting both ends of the motor shaft. Blower with damper as described.