JPH01167500A - Air blower - Google Patents

Abstract

PURPOSE:To intend to reduce noise without reducing delivery gas quantity by providing circular arcs with radii larger than the gap between a covering member and a vane wheel on corners facing to the vane wheel, on the covering member that separates discharge opening. CONSTITUTION:A covering member 6 is provided inside of a frame 1 and gas is discharged from a discharge opening 5 when a vane wheel 2 rotates anticlockwise and from a discharge opening 4 when the same rotates clockwise. Curved surface portions 8 are provided on corner portions of the covering member 6 facing to the vane wheel 2, and it is constructed so as to reduce high frequency noise generating here on existing article when gas breaks away.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small centrifugal blower for cooling the extreme parts of equipment and elements that use a heat generating body or a heat source, and relates to noise countermeasures thereof.

(Prior art' technology) As shown in Fig. 2, the blades are rotated by the motor 3, the gas flowing in from the suction lower is guided along the inner surface of the frame 1, and the gas is discharged from the discharge port 4 or 5. In addition, regarding the selection of the discharge port, a shielding member 11 is provided inside the frame 1, and the gas is discharged from the discharge port 5 when the rotation is counterclockwise as viewed from FIG. 2(a), and from the discharge port 4 when the rotation is clockwise. I was vomiting. In addition, the shielding member 11 increases the flow path resistance between the discharge ports 4 and 5, and specifically serves to minimize gas leakage to the discharge ports 4 during counterclockwise rotation and to the discharge ports 5 during clockwise rotation. was doing. Therefore, the gap between the outer periphery of the impeller 2 and the blocking member 11 is kept as small as possible. Due to the function of such a shielding member 11,
By selecting the rotational direction of the motor 3, the discharge port and the discharge direction can be controlled.

(Problems to be Solved by the Invention) However, in order to increase the flow path resistance of the discharge port by the shielding member 11, it is necessary to suppress the gap between the impeller 2 and the shielding member 11 as small as possible, and to set the member corner 12 at an acute angle. By doing so, the structure was designed to help the separation of the high-speed flow in the flow path and reduce the flow velocity, but due to the separation of the high-speed flow at the component corner 12. High frequency.

This had led to the problem that noise was occurring.

The purpose of the present invention is to reduce this high-frequency noise to ensure quietness when cooling the extreme parts of equipment and elements, and also to provide a small-sized blower that is sufficiently quiet even when used in multiple units. .

[Means for solving problems]

The blower of the present invention is mainly a centrifugal blower in which a discharge port is separated into a first discharge port and a m2 discharge port by a blocking member, and the radius of the blocking member is larger than the gap between the blocking member and the impeller. It is characterized by providing an arc at the corner facing the impeller.

(Example) As shown in FIG. 1, the impeller 2 is rotated by the motor 3,
Gas flows in from the loa to Jealousy. The inflowing gas is guided along the inner surface of the frame 1, and the gas accelerated at high speed is discharged to the outside from the discharge port 4 or 5. A shielding member "6" is provided inside the frame 1, and gas is discharged from the discharge port 5 when the impeller 2 rotates counterclockwise and from the discharge port 4 when the impeller 2 rotates clockwise. 4 and 5, and suppresses as much as possible the leakage of gas to the discharge port 4 during counterclockwise rotation and to the discharge port 6 during clockwise rotation.Therefore, the impeller 2 and the shielding member B The gap between the two is as small as possible.

The present invention has a structure in which the curved surface portion 8 is provided at the corner of the shielding member 6 facing the impeller 2, thereby reducing high frequency noise generated when gas is separated at this portion in conventional products.

In this embodiment, the curved surface portion 8 has an arcuate cross section.
The radius of this arc can be determined based on various factors such as the number of revolutions of the impeller 20, the gap between the shielding member 6 and the impeller 2, and the area of the discharge port 4.5, but if the radius of the arc is too large, Since the resistance of the discharge flow path increases and the flow path resistance to the other discharge port decreases, leakage to the other discharge port increases. Therefore, although the high frequency noise is reduced, a problem arises in that the amount of discharged air is reduced.

In the present invention, although it depends on the interval between the discharge ports 4.5, when the impeller 20 rotation speed is 1000 to 1200 Orpm or more,
By selecting the radius of the arc of the curved surface portion 8 to be about 1 to 3 times the gap between the shielding member 6 and the impeller 2,
The shape of the zero-curved surface portion 8, which has succeeded in reducing high-frequency noise to an audibly good level without substantially reducing the amount of discharged gas, is the shape of the wall surface θ of the shielding member 8, in addition to the circular arc.
If the shape connects the a18b with a smooth curved surface, the same effect can be obtained even if it is not a circular arc.

(Effects of the Invention) The small centrifugal blower of the present invention can reduce noise when cooling the extreme parts of the heat generating parts and elements of '0AII equipment, etc. This also made it possible to achieve localized cooling.

[Brief explanation of the drawing]

, FIG. 1 shows a centrifugal blower of the present invention, (&) is a sectional view taken along line AA' from the gas inlet side, and (b) is a front view taken from the gas outlet side. FIG. 2 shows a conventional centrifugal blower, in which (a) is a sectional view taken along the line nn' as seen from the gas inlet side, and (b) is a front view seen from the gas outlet side. 1... Frame 2... Impeller 3... Motor 4, 5... Discharge port 6... Shield member 7... Suction port 8... Arc 11... Shield Member 12...More than the shielding member corner (7

Claims (1)

[Claims] In a centrifugal blower consisting of an impeller having a plurality of radially arranged blades and a frame for guiding gas, the discharge port is separated into a first discharge port and a second discharge port by a shielding member. and an arc having a radius larger than the gap between the shielding member and the impeller is provided at a corner facing the impeller in the shielding member.