JPS6314020A - Cross flow fan - Google Patents

Abstract

PURPOSE:To reduce noise while maintaining a high fan efficiency, by a method wherein, the tongue of a stabilizer is formed so as to recede from the outer periphery of a cross flow fan gradually in the axial direction of the title cross flow fan. CONSTITUTION:The title cross flow fan consists of a cross flow fan F, in which a plurality of the unit bodies 3 of impellers arranged with a plurality of blades 1 into a column type with an equal pitch are combined in the direction of the rotary shafts thereof, a motor for driving the rotation of the fan F, a rear guider 4, which forms a part of the flow path of air, and a stabilizer 5, which constitutes a blow-off port 7 and is provided with a tongue at a position approximating and opposing to the fan F. The ridge line of the tongue is determined so that a gap S between the tip end of the tongue of the stabilizer and the outer periphery of the fan F is kept in constant and the end of the tongue is displaced continuously on the coaxial circumference with the rotary shaft of the fan F within the range of the length of the impeller. Further, the ridge line is determined so that respective straight ridge line parts are changed in parallel to the rotary shaft of the fan F, the length of said ridge line is longer than 1/5 of the total length of the unit body 3 but not exceeds the total length of the same, parallel to each other and changes in the shape of recesses and projections respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a cross-flow blower installed in an air conditioner or the like.

2. Description of the Related Art The structure of a conventional cross-flow blower is, for example, as shown in FIGS. 3 and 4 of the 1980s.

That is, an impeller unit 3 consisting of a plurality of blades 1 and support end plates 2 for supporting and fixing each grade 1 is arranged in the center, and an air flow path is formed around it by a rear guider 4 and a stabilizer 5, A cross-flow blower having a suction port 6 and a blowout lower was configured.

A cross-flow blower with this structure is thinner than other blowers, and has a structure in which air is taken in and discharged from one side, and the air volume increases or decreases depending on the axial length of the impeller. Because it has characteristics such as being able to be adjusted proportionally, it has come to be widely used in air conditioners and the like in recent years.

Problems to be Solved by the Invention However, the cross-flow blower having the above configuration has problems such as high noise and low efficiency compared to other blowers such as centrifugal blowers. The noise generated in the vicinity of 5 is the loudest peculiar sound caused by the fan, and it has become necessary to suppress its generation. The frequency of this unique sound is expressed by the following equation using the number 2 of blades 1 of the impeller 3, the number of revolutions per minute n (rpm), and its multiple K, and the normal blade pitch is called sound. K-11 (HZ) Because it often occurs in the frequency band that is easiest to hear within the audible range, it is perceived as a whistling noise, and measures to reduce it have become necessary.

In addition, the strength of the blade pitch sound changes depending on the shape and relative position of the impeller 3, stabilizer 5, and rear guider 4, the load during operation, etc., so measures to reduce the blade pitch sound and the height of the blower are required. This is often at odds with designing for efficiency.

For example, in FIG. 4, by reducing the gap S between the outer periphery of the impeller 3 and the stabilizer 5 cc, the blower efficiency is improved, but the blade pitch noise becomes sharply higher.

As described above, the cross-flow blower has the disadvantage that efficiency must be sacrificed in order to suppress the generation of blade pitch noise.

In view of the above-mentioned conventional problems, the present invention provides a cross-flow blower that produces extremely little noise while maintaining high blower efficiency.

Means for Solving the Problems In order to solve the above problems, the cross-flow blower of the present invention has a single impeller in which a plurality of blades having a certain length are arranged in a cylindrical shape at equal pitches, and a plurality of impellers are arranged in the direction of the rotation axis. a motor that connects and rotates one end of the cross-flow fan, and a rear guider that supports and fixes the other end of the cross-flow fan and the motor, and also forms a part of a flow path. , consisting of a stabilizer located near the front downstream side of the cross-flow fan to form the other part of the flow path, and also forming an air outlet together with the rear guider, and having a tongue portion at a position close to and facing the cross-flow fan. and the gap between the tip of the stabilizer tongue and the outward opening of the cross-flow fan is kept constant, and the tip of the stabilizer tongue continuously changes on a circumference concentric with the rotation axis of the cross-flow fan within the length range of the impeller. The tongue ridge line is defined so that the straight line portion of each ridge line is parallel to the rotation axis of the cross flow fan, and the length of the ridge line is 175 mm or more and does not exceed the total length of the impeller alone. The tongue ridge line is defined so as to vary irregularly in a concave and convex shape.

Function: With the above-described configuration, the present invention can disperse the repetition timing and overlap of the blade pitch sound of each individual impeller by changing the position of the stabilizer pipe. These blade pitch sounds with different timings interfere with each other and cancel each other out, making them audibly indistinguishable from other fluid noises, and the noise level is significantly reduced.

Furthermore, since the stabilizing tongue portion ridge lines parallel to the blade are distributed, it is possible to reduce noise without deteriorating the air blowing performance.

When the impellers of the cross-flow blower of the present invention have unequal pitch angles, the sound pressure fluctuations are deviated in time by the change in the relative position of the stabilizer with respect to the center of the impeller axis. Similarly, blade pitch noise is significantly reduced by intentional disturbances due to unequal pitch angles between each blade.

Example Embodiments of the present invention will be described below with reference to the accompanying drawings.

Components that are the same as those in the conventional example are given the same reference numerals and description thereof will be omitted.

In FIGS. 1 and 2, the stabilizer 5 is provided so that its tongue tip is located on a concentric circle spaced apart from the center of the impeller 3 by a gap S, and the stabilizer 5 is parallel to the central axis of the impeller 3. It has a tongue ridge line, has a length of 175 or more and does not exceed the total length of the impeller unit 3, and has an uneven shape with adjacent straight parts offset by an angle θ with respect to the axis center of the impeller unit 3. They are arranged irregularly, have a length between each straight line portion that is 115 or more but not more than the total length of the impeller unit 3, and are connected by smoothly continuous tongue ridge lines. FIG. 2 is a superimposition of vertical cross sections a and b of arbitrary adjacent straight sections in FIG.

Between the vertical planes defined by the a-a line and the b-b line, the time lag in the blade pitch sound generated at each stabilizer 5 position interferes with each other both physically and positionally, resulting in a canceling effect. As a result, blade pitch noise is reduced. In addition, since the change in the stabilizer 5 does not become larger than the pitch length of one blade of the impeller 3, the stabilizer 5 can
Feather from a position above the point.

No pitch sound is generated, and the blade pitch sound is not amplified due to interference.

Note that the stabilizer 5 can be easily manufactured by molding resin or the like.

Further, the shape of the tip of the tongue portion of the stabilizer 5 may be either a curved surface in the shape of a circular arc or an acute-angled surface.

Effects of the Invention As described above, the present invention reduces the audible blade pitch noise by forming the tongue of the stabilizer pipe so that it gradually moves away from the outer circumference of the crossflow fan in the axial direction of the crossflow fan. Therefore, it is possible to provide a quiet air conditioning blower, and it is also possible to significantly improve efficiency, which has hitherto been limited by low noise.

[Brief explanation of drawings]

1 and 2 are a perspective view and a sectional view of the main parts showing the structure of the cross-flow blower of the present invention, respectively, and FIGS. 3 and 4 are a perspective view and a sectional view of the main parts showing the structure of a conventional example. . 1...Blade, 2...Support end plate, 3
・・・・・・Single impeller, 4・・・Rear guider,
5... Stabilizer. Name of agent: Patent attorney Toshio Nakao and 1 other person7-
--Blade 2- Support M1 slope 3- Figure 5-11 Squbilizer 6-Suction U 7-Outlet no. 1-Blade Figure 2 3-Blade beam 4 ---Rear sword] f da 5 --- Nutabilite' 61 -- Suction port' i a lvl Fig. 3

Claims (3)

[Claims] (1) A cross-flow fan consisting of a plurality of individual impellers each having a plurality of blades having a certain length arranged in a cylindrical shape at equal pitches, combined in the direction of the rotation axis, and one end of the cross-flow fan connected and driven to rotate. a rear guider that supports and fixes the motor to the other end of the cross-flow fan and forms a part of the flow path; and a stabilizer which forms an air outlet together with the rear guider and has a tongue at a position close to and facing the cross-flow fan, and maintains a constant gap between the tip of the stabilizer tongue and the outer periphery of the cross-flow fan. and a tongue ridge line is defined so that the tip of the stabilizer tongue continuously changes on a circumference concentric with the rotation axis of the cross flow fan within the length range of the impeller; The tongue portions are parallel to each other, and the straight portions of the ridge lines are parallel to each other and the length of the ridge line is 1/5 or more of the total length of the impeller alone, but does not exceed the total length, and each of the ridge line straight portions is parallel and irregularly changes into a concave and convex shape. A cross-flow blower with a defined crest line. (2) The length between the adjacent straight line portions of the ridge line is 1/5 or more of the total length of the single impeller and does not exceed the total length,
The cross-flow blower according to claim 1, wherein the tongue portions are connected by the smoothly continuous tongue ridge line. (3) A patent claim in which the changes in the adjacent linear portions of the ridge lines continuously change at least within the length range of the single impeller with an angular width that does not exceed the pitch length of the blades of the cross flow fan. A cross-flow blower according to scope 1.