JPH0593531A - Front grille for outdoor apparatus of air conditioner - Google Patents

Abstract

PURPOSE:To reduce the noise of interference and that of breakaway both caused by the flow of air from the impeller by forming the bar for a grille in the shape of a specific airfoil with respect to a section in the direction of the axis of the impeller. CONSTITUTION:The bar of a grille is formed in the shape of an airfoil with respect to a section parallel to the axis of the impeller and made to have a pitch chord ratio t/L of approximately 1 to 4. The relation between the largest thickness (d) of the airfoil and the approximate radius R1 representing the roundness of the front edge of the airfoil is made to have a ratio of 0.2 to 0.35. The rear edge of the airfoil, with respect to the sectional shape, is formed of planes or in a shape with an approximate radius of over one half the chord length. By the contrivance described above a reduction can be achieved in the noise produced by vertices released from the rear end of the airfoil. The vertical bar 9a intersects such horizontal bars 8a of airfoil profile at right angles to form a grille in a lattice. For a wide range of angle of attack this constitution enables reducing the impact of the collision against a spiral flow which is sent by the impeller and at an angle to its axis determined by the shape of the load impeller; thus it becomes possible to reduce the noise of interference and, through reduction of the breakaway region on the surfaces of the airfoil-shaped bar, to lower the noise of breakaway as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grill used for an outdoor unit of an air conditioner, a blower duct, etc., which is required to surround the blower fan and the duct for safety reasons.

[0002]

2. Description of the Related Art An outdoor unit of an air conditioner having a conventional outlet front grille will be described with reference to the accompanying drawings.

As shown in FIG. 5, an impeller 3 and a motor 4 are housed in a space surrounded by a heat exchanger 1 and an exterior plate 2,
An orifice 5 is provided around the impeller 3. The exterior plate 2 facing the downstream side of the impeller 3 is provided with a blowout port 6, and a grill 7 is attached to the outside thereof. The motor 4 is fixed to the exterior plate 2 by a motor support base 8 as shown in FIG.

In such a structure, the external air is sucked from the heat exchanger 1 side by the rotation of the impeller 3 directly connected to the motor 4, and is discharged from the grill 7 through the outlet 6 to the outside.

Conventionally, the grill 7 is made of a wire having a circular cross section and a resin having a substantially rectangular cross section, and is formed in a lattice shape on a plane parallel to the front surface of the exterior plate 2 with an appropriate distance. It was arranged.

[0006]

However, in the grille cross-sectional shape as described above, the interference sound due to the collision between the flow discharged from the impeller 3 and the crosspiece or the outflow is generated in the middle of the circular cross section and the front and rear edges of the rectangular cross section. There is a problem in that the air is separated from the edge portion of the edge and becomes a large resistance to the flow, so that the blowing performance is deteriorated.

The present invention is intended to solve the above-mentioned problems of the conventional example, and it is an object of the present invention to suppress the above-mentioned interference noise and peeling noise as much as possible, and to reduce the noise level as an outdoor unit and suppress the reduction of the air volume. .

[0008]

In order to solve the above-mentioned problems, the present invention is one in which the cross-sectional shape of the grille bar in the axial direction of the impeller is a wing shape.

In order to solve the above-mentioned problems, the present invention, as described above, has an approximate radius R1 of the roundness of the leading edge of the blade and a maximum thickness d of the blade.
The ratio R1 / d is set to 0.2 to 0.35.

In order to solve the above-mentioned problems, the present invention, as described above, sets the trailing edge of the blade to a flat surface or a chord length of 1
The shape has a substantially diameter of ½ or more.

[0011]

According to the present invention, by making the cross-sectional shape of the above-mentioned grille in the axial direction of the impeller into a blade shape, a well-known angle having an angle with respect to the impeller axial direction determined by the shape of the load impeller discharged from the impeller 3 is known. The influence of collision on the swirling flow can be reduced over a wide range of attack angles, noise as interference noise can be suppressed, and at the same time, the separation region on the airfoil surface can be reduced to suppress separation noise.

Further, according to the present invention, as described above, the ratio R1 / d between the radius R1 of the roundness of the leading edge of the blade and the maximum thickness d of the airfoil is set to 0.2 to 0.35. It is possible to suppress the interference sound with the blowing flow while preventing the leading edge separation.

Further, according to the present invention, as described above, the end face of the trailing edge portion of the blade has a flat surface or a shape having a substantially diameter equal to or more than ½ of the chord length, so that the blade is discharged from the trailing edge of the blade. The sound generated by the vortex can be reduced.

[0014]

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

FIG. 1 is a view in which the grill having the horizontal rails having the above-mentioned blade cross-sectional shape is attached to the front surface of the exterior plate. Figure 2
4 is a detailed view of a cross-sectional shape of a horizontal rail row corresponding to each claim, 8a to 8c are horizontal rails having the above-mentioned airfoil section, and 9a to 9c are vertical rails for holding the horizontal rails. Forming a grid grill.

[0016]

As is apparent from the above description, the present invention has the following advantages.
By making the cross-sectional shape of the grille in the impeller axial direction a wing shape, it is possible to suppress the noise of interference with the flow of the air discharged from the impeller 3 and the noise of peeling caused by peeling to be lower than the conventional shape.

According to the present invention, as described above, the ratio R1 / d between the radius R1 of the roundness of the leading edge of the blade and the maximum thickness d of the airfoil is 0.2.
By setting it to 0.35, it is possible to prevent the leading edge separation and suppress the interference sound with the blowing flow.

As described above, according to the present invention, the end surface of the trailing edge portion of the blade is formed into a plane or a shape having a diameter substantially equal to or more than 1/2 of the chord length, so that the generation by the vortex emitted from the trailing edge of the blade is generated. The sound can be reduced.

The noise level when the grill is attached to the exterior plate 2, that is, the noise level as an outdoor unit is
It is possible to lower the value with the same air volume as the conventional one.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an air conditioner outdoor unit to which an airfoil cross-sectional shape outlet front grill is attached according to an embodiment of the present invention.

FIG. 2 is a detailed sectional view of the grill according to claim 1.

FIG. 3 is a detailed sectional view of the grill according to claim 2.

FIG. 4 is a detailed sectional view of the grill according to claim 3.

FIG. 5 is a cross-sectional view of an air conditioner outdoor unit to which a conventional circular cross-sectional shape outlet front grill is attached.

[Fig. 6] Detailed view of the cross section of the grill

[Explanation of symbols]

 1 Heat Exchanger 2 Exterior Plate 3 Impeller 4 Fan Motor 5 Orifice 6 Blowout Port 7 Grill 8 Airfoil Cross Section Horizontal Bar 9 Vertical Holding Bar

Claims (3)

[Claims] 1. A cross section of a crosspiece of a crosspiece with respect to an axial direction of the impeller, which is provided on the downstream side of an outlet of an air blower that discharges air from the impeller to the outside through an outlet, has a chord ratio t.
/ L is approximately 1 to 4, which is a front grill for an outdoor unit of an air conditioner, which is composed of horizontal rails. 2. An approximate radius R of the roundness of the leading edge from the airfoil shape
1 and the maximum thickness d of the airfoil have a ratio R1 / d of approximately 0.2 to 0.
The front grille for an outdoor unit of an air conditioner according to claim 1, wherein the front grille is formed of a horizontal row. 3. The air conditioner according to claim 2, wherein the end face shape of the trailing edge portion of the airfoil shape is a plane or a horizontal row of airfoil cross sections having an approximate diameter of 1/2 or more of the chord length. Front grille for the outdoor unit of the machine.