JPH09242697A - Blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a noise by changing a clearance formed by the periphery of a fan and a casing guide. SOLUTION: This blower is so formed that a fan 2 is arranged in a casing, and the fan 2 is rotatively driven so that air is sucked from a bell mouth formed in the casing and discharged from a discharge opening formed in the casing. In this case, the fan 2 is arranged in the casing so that a clearance A between a easing guide 1 composing the casing and the periphery of the fan 2 is minimized in a range of from 60 deg. to 145 deg. of the volute angle of the casing guide 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower used in, for example, an indoor unit of an air conditioner, and more particularly, to a blower by specifying the position of a cylindrical multiblade fan arranged in a casing. The present invention relates to a blower capable of reducing noise during use.

[0002]

2. Description of the Related Art FIG. 5 (a) is a sectional view of a conventional centrifugal blower having a spiral wound casing. In the figure, 1 is a casing guide, 2 is an impeller of a blower (cylindrical multi-blade fan), 3 is the center of the impeller, 4 is the nose portion of the swirling flow path of the casing guide, that is, the winding start portion, and 5 is the above. A wall surface 6 of the swirling flow path 7 is a discharge port. In this blower,
When the impeller 2 rotates, the gas inside the impeller 2 becomes a suction flow and is pushed out to the swirl flow path 7, and becomes a discharge flow 8 in the swirl flow path 7 while being swirled out from the discharge port 6. It At that time, in the nose portion 4, a part 9 of the discharge flow becomes an entrained flow and enters the swirl flow path again through the gap of the nose portion 4. In the figure, θ is the winding angle measured from the nose portion 4 of the swirl flow path 7, and r is the radius of the swirl flow path wall surface (guide wall surface) 5 measured from the center of the impeller.

FIG. 5 (b) is a diagram showing the relationship between the winding angle θ and the swirling flow path wall radius r in the conventional casing manufactured at one enlarged angle. As shown in the figure, conventionally, the relationship between the angle θ and the radius r has been designed to maintain a linear relationship in which the radius r gradually increases over the entire range. Therefore, in the conventional casing, there is a problem in that the flow of the suction flow is disturbed by the flow of the entrainment flow into the swirling flow path, and noise is generated in the nose portion 4. Further, due to this entrainment flow, the suction flow is pushed back toward the impeller to form the return flow 12, which has been a cause of deterioration in aerodynamic performance. In order to solve the above problems, in Japanese Utility Model Laid-Open No. 2-74599, a centrifugal blower having a spiral wound casing is provided with an outwardly bulged portion near the nose portion of the casing. Proposing a blower.

[0004]

However, the above-mentioned blower does not have the expected noise reduction effect and the casing guide has a complicated shape, which increases the man-hours required for molding the guide and makes it difficult to assemble. There is a problem in that it is disadvantageous.

In order to solve the above problems, the inventors of the present invention have made earnest studies on the shape of the casing guide of the blower and the positional relationship between the fan and the casing guide. As a result, the outer periphery of the fan and the casing guide are It was found that the gap formed is an important factor in reducing noise, and the relation with noise was examined while changing the gap between the fan outer periphery and the casing guide. as a result,
Noise is generated when the gap between the two is minimized in the range of the casing winding angle of 60 ° to 145 ° (angle formed from the reference line described later) while maintaining the guide shape as it is, and preferably in the vicinity of 125 °. It was confirmed that the air flow rate-static pressure characteristics were improved as well as the air flow rate was most reduced.

[0006]

Therefore, according to the present invention, a fan is arranged in a casing, and air is sucked from a bell mouth formed in the casing by driving the fan to rotate from a discharge port formed in the casing. A blower for discharging air, wherein a gap A between a casing guide forming the casing and an outer periphery of the fan has a winding angle of 60 ° to 145 measured from a reference line.
The blower is characterized in that a fan is arranged in the casing so as to be the minimum in the range of °, and this is a means for solving the problem.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a relationship between a casing guide and a fan of a blower according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 is a guide for a casing of a blower, and a throat portion 4 is formed in the casing guide 1 as in the conventional product. The casing guide 1 starts from the throat portion 4 as a casing. The radius r from the center (center of the conventional fan) is gradually increased. A fan 2 having a well-known configuration is arranged in the casing guide 1, and is arranged so that the center position of the fan is a position 3a lower than the center part of the casing as shown in FIG. There is.

At this time, the center 3a of the fan is arranged so that the distance (gap) A between the inner peripheral surface of the casing guide and the outer peripheral surface of the fan is minimized when the winding angle from the reference line is 125 °. It is lower than the center 3 by a distance s. Here, the reference line is a line connecting the center point of the radius forming the "throat" of the casing and the center point 3 of the casing as shown in FIG. 1, and the casing guide radius r gradually increases from this reference line. The winding angle taken in the increasing direction is positive.

The distance (gap) A between the inner peripheral surface of the casing guide 1 and the outer peripheral surface of the fan 2 is minimized at least when the winding angle from the reference line is 60 ° to 145 °. (In this case, the center point of the fan is naturally deviated from the line of 125 ° except for the winding angle of 125 °). Further, as described above, the winding angle is approximately 125 °. The noise reduction effect is further enhanced in the vicinity.

FIG. 2 shows the relationship between the casing winding angle θ and the distance A between the casing guide 1 and the outer periphery of the fan 2. In this graph, the dotted line is the conventional blower, and the solid line is the blower according to the present invention. As is clear from the graph, in the present invention, the distance A between the casing guide 1 and the outer circumference of the fan is such that the casing winding angle from the reference line is 125 °.
It is the smallest in position. With this arrangement, the noise of the product of the present invention is lower than that of the conventional product as shown in FIG. 3, and the air flow-static pressure characteristic diagram is also shown in FIG.
As shown in, the product of the present invention is improved. As described above, according to the present invention, noise and air volume can be reduced compared to the conventional product by only changing the positional relationship between the casing guide of the blower and the fan.
The static pressure characteristics can be improved.

Needless to say, the present invention can be implemented in various other forms without departing from the spirit or main characteristics of the present invention. Therefore, the above-described embodiments are merely examples in all respects. And should not be construed as limiting.

[0013]

As described in detail above, according to the present invention, the gap between the casing guide and the outer periphery of the fan has a casing winding angle, that is, a winding angle from the reference line of 60 °.
It is characterized by arranging the fan in the casing so as to be the minimum in the range of 145 °, and as a result, it has an excellent effect that the noise during air blowing is significantly reduced and the air volume-static pressure characteristic can be improved. be able to.

[Brief description of drawings]

FIG. 1 is a side view of a casing and a fan of a blower according to an embodiment of the present invention.

FIG. 2 is a diagram showing a gap between a casing and a fan of the present invention and a conventional product.

FIG. 3 is a noise comparison diagram of the present invention and a conventional product.

FIG. 4 is a comparison diagram of airflow-static pressure characteristics of the present invention and a conventional product.

FIG. 5 is a side sectional view of a casing of a conventional blower and a fan, and a diagram showing a relationship between a winding angle and a radius of a casing of a conventional product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing guide 2 Fan 3 Center of conventional fan 3a Center of fan of the present invention 4 Throat portion A Gap between casing guide and fan outer periphery

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Endo 2-499 Aioi-cho, Kiryu-shi, Gunma Akaishi Metal Industry Co., Ltd.

Claims (1)

[Claims] 1. A blower in which a fan is arranged in a casing, and the fan is rotated to suck air from a bell mouth formed in the casing and discharge the air from a discharge port formed in the casing. The fan is arranged in the casing such that the gap A between the casing guide forming the casing and the outer circumference of the fan is minimized within the range of the winding angle of the casing guide of 60 ° to 145 ° as measured from the reference line. Characterized blower.