JPS60119399A - Blower - Google Patents

Abstract

PURPOSE:To prevent the generation of counterflow and metallic noise by installing a counterflow preventing plate formed by bending the edge part on the wind upstream side towards the shaft center side of a Sirocco fan in close to the inner peripheral surface of the vane of the fan on the periphery of the throat part formed at the effluence port of a fan casing. CONSTITUTION:Air is inhaled from an inflow port 3 by the blower action of a Sirocco fan 1 and sent outside the system from an effluence port 4. A low pressure is generated inside the fan 1, and a high pressure is generated outside, and the pressure difference is made max. on the periphery 5 of the throat of a fan casing 2. However, the counterflow from outside the fan 1 to the inside of the fan 1 is prevented by the action of a counterflow preventing plate 6 formed by bending the edge part on the wind upstream side towards the shaft center side of the fan 1 in close to the inner peripheral surface of the fan 1 on the above-described periphery 5. Though a pressure difference is generated between the front and the back surfaces of a vane, and a pulsation flow is generated, the pressure impact onto the counterflow preventing plate 6 is lightened by the bent part 7, and the generation of the metallic noise by the counterflow preventing plate 6 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improved performance and reduced noise of a blower comprising a Chiron fan.

A conventional feeding machine consisting of a sirocco fan is shown in Figure 1.
A fan casing 2 is installed surrounding the sirocco fan 1 (
An inlet 3 is provided on the side of the fan casing 2 coaxial with the fan, and an outlet 4 is provided on the circumference of the fan casing.
It was a structure that provided.

However, with this structure, because the length of the Chiron fan blades is short, the pressure difference between the inside and outside of the Scirocco fan causes a backflow from the fan casing flow path side to the inside of the Chiron fan, as shown by the arrow. The backflow interferes with the blower's operation and creates turbulence, which reduces blower efficiency and causes noise.

The present invention aims to eliminate the above-mentioned drawbacks, and includes providing a fan casing surrounding the Sirocco fan, providing an inlet on the side surface of the fan casing coaxially with the Sirocco fan, and An outflow port is provided on the circumference, a backflow prevention plate is provided near the inner peripheral surface of the fan blade around the throat formed at the outflow port of the fan casing, and a backflow prevention plate is provided at the upstream end of the backflow prevention plate. The Chiron fan is folded towards the axis of the fan. It is.

Hereinafter, the present invention will be explained based on the drawings. FIG. 2 is an explanatory diagram of one embodiment of the present invention, and FIG. 3 is an explanatory diagram of an embodiment of the present invention.
4 is an enlarged view of section B in FIG. 2. 1 in the figure is a sirocco fan, and a fan casing 2 is provided surrounding this sirocco fan. An inflow port 3 is opened in a side surface of the fan casing 2 coaxially with the sirocco fan 1 with a diameter slightly smaller than the inner diameter of the blades of the sirocco fan 1. An outflow port 4 is provided in a tangential direction on the circumference of the fan casing 2, and a throat portion 5 is formed at the joint between the outflow port 4 and the fan casing 2. A backflow prevention plate 6 is provided around the throat portion 5 of the fan casing 2 and close to the inner peripheral surface of the blades of the Chiron fan 1.

This backflow prevention plate 6 has a width slightly smaller than the width of the blades of the Chiron fan 1, and is provided in the circumferential direction to cover the throat 5 of the fan casing 2. It is bent toward the fan axis.

A motor 8 for driving the sirocco fan is provided at the fan casing on the side opposite to the inlet, and the motor 8 is connected to the sirocco fan.

To explain the operation in the above configuration, the Chiron fan rotates by driving the motor. Then, air is sucked in from the inlet by the feeder action of the Siron fan, pressurized by the Sirocco fan blades, and then pumped out of the system from the outlet. At this time, the pressure inside the sirocco fan is low, and the pressure outside is high.

This becomes especially large when there is a pressure difference around the throat of the fan casing. However, due to the action of the backflow prevention plate,
Prevents backflow from the outside to the inside of the fan. In addition, a pressure difference occurs in the air flow between the front and back of the blades of the sirocco fan, creating a pulsating flow, but when the blade approaches the backflow prevention plate, the pressure impact on the backflow prevention plate is alleviated at the bent part, and the backflow prevention plate Prevents the metal sound that occurs when cutting.

By preventing backflow as described above, the present invention makes it possible to smooth the flow of air within the fan casing and increase the static pressure rise of the blower. It can reduce noise and periodic flapping noise. Furthermore, by providing a bent part on the backflow prevention plate, the pressure impact on the bent part of the pulsating flow due to the pressure difference generated between the front and back sides of the Chiron fan blades is alleviated, and the metallic sound generated by the backflow prevention plate is reduced. To prevent.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional blower, FIG. 2 is an explanatory diagram of an embodiment of the present invention, FIG. 3 is a sectional view taken along line A-A in FIG. 2, and FIG.
It is an enlarged view of the part. 14 Shirotsu” fan 2. Fan casing 3, inlet 4. Outlet 5, throat 6. Backflow prevention plate 7, end 8. Motor patent applicant Yasuzu Miura Representative Miura Kogyo Co., Ltd. 3 Figure 4

Claims (1)

[Claims] A fan casing 2 is provided surrounding the "Chiron" fan 1, an inlet 3 is provided on the side of the fan casing 2 coaxial with the Sirocco fan 1, an outlet 4 is provided on the circumference of the fan casing 2, and the flow of the fan casing 2 is A backflow prevention plate 6 is installed close to the inner peripheral surface of the blade of the Sirocco fan 1 around the throat 5 formed at the outlet, and the upstream end 7 of the backflow prevention plate is bent toward the axis of the Sirocco fan. A blower characterized by: