JPS603359Y2 - sound deadening cover - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a noise-absorbing cover for preventing noise from a radial fan or a multi-blade centrifugal fan, etc.

Various attempts have been made for this purpose, but none of them are satisfactory.

For example, there is a muffling device in which a duct is connected to the air intake port and a muffling box is provided at the air inlet, but this is inconvenient because the area occupied by the duct is large compared to the size of the fan.

Usually, an air suction port is provided that is bent in a direction perpendicular to the fan suction port for noise reduction, but the noise from the fan is directly radiated from the fan suction port to the air suction port, and the noise reduction effect is small.

In addition, a fan with a rectifier cover installed on the fan suction port (Jikko Sho 39)
(Refer to Japanese Patent No. 25526), but the purpose of this is to reduce eddy current and increase the efficiency of the fan, not to block noise.

The present invention has a configuration different from conventional ones, and suppresses the generation of suction noise by preventing fan noise from being directly dissipated to the outside, and by preventing local vortices as much as possible when the suction air flows. It is something.

Specifically, a barrier configured to enclose half of the outer periphery of the fan inlet from the base of one side of the air inlet of the sound-absorbing cover or near the base in a sound-absorbing cover installed in front of the fan inlet. A movable plate is provided to form a swirling air inflow path between the barrier and the inner surface of the sound deadening cover, and to block a part of the inlet of the air intake port of the sound deadening cover on the opposite side opposite to the barrier mounting side. Further, the movable plate is provided with a curved surface portion that throttles and rectifies a part of the air inflow path.

Referring to the accompanying drawings, FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along line XX in FIG. 1.

In the figure, 1 is a sound deadening cover, 2 is a barrier, 3 is a movable plate for adjusting air volume, 4 is a curved surface, 5 is a fan casing, A is an air inlet, B is an air inflow path, C is a fan inlet, and E is a fan, and F is a motor.

In the above, the barrier 2 is arranged so as to surround the fan suction port C, and blocks the fan noise from being linearly dissipated toward the air suction port A.

The barrier 2 is made of a sound-absorbing material or a rigid wall fitted with a sound-absorbing material to improve the sound insulation effect.

The air inflow path B formed by the barrier 2 and the main body of the sound-absorbing cover 1 has a cross-sectional area that gradually decreases from the entrance and gradually increases from the middle to prevent the generation of vortices.

A part of the noise coming out through the air inflow path B collides with the barrier 2 and the sound-absorbing cover 1, is absorbed, and is reflected repeatedly, and is attenuated.

The other part goes straight to the air suction port A on the way.

As a result of the actual measurement, the noise emitted at A is biased towards the A' side in FIG.

In order to prevent this, reducing the cross-sectional area of the air inlet passage B and making the passage longer increases resistance loss, which is uneconomical.

Therefore, a movable plate 3 for adjusting the air volume with a curved surface part 4 attached thereto is provided at the air suction port so as to improve the sound insulation effect by blocking the A' portion without increasing the resistance, and to rectify the incoming air and suppress the generation of vortices.

This muffling cover can be mounted in any angular position by rotating it relative to the fan casing.

Furthermore, the silencing effect can be enhanced by changing the direction of the air suction port as shown in FIG.

That is, in FIG. 3, compared to FIG. 1, the air suction port A is made to hang downward, so that air is taken in from below, and the noise reduction effect is also greater.

In short, the present invention has practical value because it provides an effective and appropriate sound damping effect by providing a sound damping passage and equipping the fan suction port with the specific cover described in the claims.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention, FIG. 2 is a sectional view taken along line XX in FIG. 1, and FIG. 3 is a longitudinal sectional view of another embodiment. 1... Sound deadening cover, 2... Barrier, 3.
...Movable plate, 4...Curved surface part, 5...
...Fan casing, A... Air intake port, B
... Air inflow path, C ... Fan suction port, E ... Fan, F ... Motor.

Claims (1)

[Scope of utility model registration request] A barrier is provided in the sound-absorbing cover installed in front of the fan suction port, and is configured to surround one half of the outer periphery of the fan suction port from one side base of the air suction port of the sound-muffling cover or from near the base. A movable plate is provided between the barrier and the inner surface of the sound deadening cover to form a circulating air inflow path, and also to block a part of the inlet of the air suction port of the sound deadening cover on the opposite side opposite to the barrier mounting side. A sound-absorbing cover in which the plate is provided with a curved part that throttles and rectifies a part of the air inflow path.