JPS6137840Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a centrifugal blower, and more particularly to a centrifugal blower that damps the pulsation of suction gas that causes noise.

Generally, an air conditioner for an automobile is equipped with a centrifugal blower, and the centrifugal blower is used to blow air. By the way, this centrifugal blower 1 is
As shown in the figures and FIG. 2, a casing 2 has a blade wheel 3 fitted therein, and the blade wheel 3 is mounted on a shaft 4a of a motor 4 fixed to the casing 2 so as to rotate. . The blade wheel 3 has a large number of blades 3a arranged around its periphery, and an air intake port 3b that opens near the inner end of the blade 3a is formed at the center of one end of the blade wheel 3. The other end of the blade 3a is hermetically sealed with a truncated conical disk 3c protruding into the impeller 3, and the center of the disk 3c is fixed to the shaft 4a of the motor 4. In addition, the aforementioned impeller 3 and casing 2
The gap S between them gradually becomes larger in the air outflow direction, and is designed to collect the outflowing air and guide it toward the blower outlet 1a.

However, in such a conventional centrifugal blower 1, the pressure within the gap S between the impeller 3 and the casing 2 of the centrifugal blower 1 increases as the air discharged from the impeller 3 approaches the blower outlet 1a. Then, the pressure gradually increases and reaches 40 to 50 mm (water column) at the outlet 1a, so that blowback occurs on the outlet side. Since this blowback is not constant but repeatedly fluctuates, this fluctuation causes a vortex in the airflow inside the blower, causing unstable pulsation. This pulsation causes a pulsating sound in the blower, causing a problem.

In view of these conventional problems, the present invention is designed to reduce the pulsation noise of the blower by disposing a pulsation damping member for damping the pulsation of the intake gas inside the air intake port 3b of the impeller. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, in which the same parts as those in the conventional structure are denoted by the same reference numerals.

In FIG. 3, reference numeral 3 denotes a blade wheel disposed within the casing 2, and this impeller 3 has blades 3a disposed on its peripheral edge as in the conventional case, and has an air intake port 3b at one end.
The other end is sealed with a disk 3c.
Here, the present invention provides a pulsation damping member 10 which has a disc shape with a diameter slightly smaller than the inner end diameter of the blade 3a and is made of a thin flexible member.
is placed inside the air intake port 3b, and the center portion of this pulsation damping member 10 is attached to the shaft 4a of the motor 4 on which the disk 3c is attached with a spacer 11.
These pulsation damping members 1
0. The spacer 11 is fixed to the disk 3c with a nut N screwed onto the end of the shaft 4a, so that it rotates integrally with the impeller 3.

In this embodiment, the pulsation damping member 10 is formed into a slightly shaded shape, and the apex thereof is connected to the air intake port 3b.
It is placed in the direction.

With the above configuration, as the centrifugal blower 1 operates, air is sucked into the impeller 3 from the air suction port 3b, and a vortex is generated in the intake air inside the air suction port 3b as described above. The swirling air impinges on the pulsation damping member 10 . At this time, the speed of the colliding air varies depending on the pulsation caused by the vortex flow, and the pulsation damping member 10 is deflected largely in areas where the air velocity is high, and conversely, the pulsation damping member 10 is deflected to a small extent in areas where the air velocity is low. In other words, since the pulsation damping member 10 is made of a thin flexible material, its rigidity due to centrifugal force due to rotation is small, so it partially bends depending on the speed of the colliding air and absorbs the pulsation energy of the air flow. and attenuates the pulsation of the intake air.

Documents of a centrifugal blower actually manufactured based on the present invention show that the diameter of the impeller is 140 mm to 150 mm, the pulsation damping member is 80 mm in diameter, 0.5 to 1 mm thick, and made of cloth-filled vinyl chloride sheet. , the attenuation of pulsating sound reaches 1 to 1.5 dB.

As explained above, in the centrifugal blower of the present invention, a disk-shaped thin flexible material is installed in the gas suction port of the impeller so that it rotates integrally with the impeller. A pulsation damping member that attenuates is disposed substantially perpendicular to the intake flow direction, and the pulsation damping member partially bends according to the velocity of the colliding gas to absorb the pulsation energy of the intake gas, thereby reducing the pulsation of the intake gas. Since the noise is attenuated, the pulsating noise generated on the air discharge side downstream of the blower can be significantly reduced, which is an excellent practical effect.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a conventional centrifugal blower, Figure 2
The figure is a sectional view of a conventional centrifugal blower, and FIG. 3 is a sectional view of a centrifugal blower according to the present invention. 1... Centrifugal blower, 3... Impeller, 3b... Gas suction port, 10... Pulsation damping member.

Claims (1)

[Scope of utility model registration request] A pulsation damping member made of a disk-shaped thin flexible material and damping the pulsation of the intake gas is installed in the gas suction port of the impeller so as to rotate integrally with the impeller, approximately in the direction of the intake air flow. A centrifugal blower characterized by being arranged at right angles.