Blower

Abstract

Provided is a blower that can increase the volume flow of gas taken into a casing while suppressing fan noise.　The blower comprises a fan, a casing accommodating the fan, and an arrangement member arranged in the casing. The casing includes: an intake port and an exhaust port positioned apart from each other iso as to sandwich the fan in the axial direction of a rotary shaft of the fan; a side wall surrounding the fan; a side intake port formed in the side wall; and a cylindrical projection projecting from the edge of the exhaust port toward the inside of the casing. The arrangement member is positioned in a target space between the projection and the side wall, and is arranged at least at a position adjacent to the portion of the projection closest to the side air intake port when viewed from the axial direction.

Description

blower

[0001] The present invention relates to a blower.

[0002] Blowers having a fan disposed inside a casing have already been developed, and one example of this is the technology described in Patent Document 1.

[0003] The outdoor fan described in Patent Document 1 has a propeller fan inside its housing, and an exhaust port is formed on the front side of the housing, a rear air inlet is formed on the rear side of the housing, and a side air inlet is formed on the left side of the housing. Air that enters the housing through the rear air inlet and the side air inlet exchanges heat with a heat exchanger (more specifically, a refrigerant in the heat exchanger) located inside the housing, and is discharged to the outside of the housing through the exhaust port.

[0004] JP 2014-153019 A

[0005] In the above-described blower, the greater the volume of gas drawn into the casing, the less power is required to control the refrigerant temperature. One way to increase the volume of air is to increase the fan rotation speed, but this method is not preferable because it increases the operating noise of the fan and causes noise.

[0006] An object of the present invention is to provide a blower that overcomes the problems of the prior art and that can increase the volume of gas drawn into the casing while suppressing noise from the fan.

[0007] To solve this problem, the present invention has the following configurations. [1] A blower including a fan, a casing that houses the fan, and a placement member arranged within the casing, wherein the casing includes an intake port and an exhaust port that are spaced apart from each other across the fan in the axial direction of the fan's rotation shaft, a side wall that surrounds the fan, a side intake port formed in the side wall, and a cylindrical protrusion that protrudes from the edge of the exhaust port toward the inside of the casing, the placement member being located in a target space between the protrusion and the side wall and at least adjacent to a portion of the protrusion that is closest to the side intake port when viewed from the axial direction. [2] The blower according to [1], wherein the placement member is made of an air-impermeable material. [3] The blower according to [2], wherein the air-impermeable material is at least one of a metal material and a resin material. [4] The blower according to [2], wherein the air-impermeable material is a closed-cell material. [5] The blower according to [1], wherein the placement member is made of a sound-absorbing material. [6] The blower according to [5], wherein the sound-absorbing material is a fiber-based sound-absorbing material. [7] The flow resistance of the fiber-based sound-absorbing material is 700 Pa·s / m ２ The above-mentioned blower according to [6]. [8] The blower according to [5], wherein the sound-absorbing material is a foam-based sound-absorbing material. [9] The blower according to any one of [1] to [8], wherein a surface extending from the side air intake toward the tip of the protrusion is located at the end of the arrangement member on the air intake side in the axial direction.

[10] The blower according to [9], wherein the surface is located at the same position as the tip of the protrusion in the axial direction.

[11] The blower according to any one of [1] to

[10] , wherein the arrangement member is arranged in the target space along the outer periphery of the cylindrical protrusion, over the entire circumferential range of the protrusion.

[12] The blower according to any one of [1] to

[11] , wherein the protrusion has an opening communicating an internal space surrounded by the cylindrical protrusion with the target space, and further comprises a breathable cover member covering the opening.

[13] The blower according to any one of [1] to

[12] , wherein the protrusion has a cross-sectional size larger at both ends in the axial direction than at the center.

[0008] According to the present invention, it is possible to provide a blower that can increase the volume of gas taken into the casing while suppressing noise caused by the fan.

[0009] 6 is a perspective view of a blower according to one embodiment of the present invention. FIG. 6 is a cross-sectional view taken along the cutting line J-J in FIG. 1 . FIG. 6 is a cross-sectional view taken along the cutting line K-K in FIG. 2 . FIG. 6 is a diagram for explaining a mechanism by which the air volume does not increase in a blower according to a comparative example of the present invention. FIG. 6 is a diagram for explaining a mechanism by which the air volume increases in a blower according to one embodiment of the present invention. FIG. 6 is a cross-sectional view corresponding to FIG. 3 of a blower according to a first modified example of the present invention. FIG. 6 is a cross-sectional view taken along the cutting line L-L in FIG. 6 . FIG. 6 is a cross-sectional view corresponding to FIG. 2 of a blower according to a second modified example of the present invention. FIG. 6 is a table showing the relationship between the conditions of the arrangement members used in the reference example, comparative examples 1 to 4, and examples 1 to 9, and the evaluation results of the reference example, comparative examples 1 to 4, and examples 1 to 9. FIG. 6 is a diagram for explaining a method for measuring the air volume of a blower. FIG. 6 is a diagram for explaining a method for measuring the sound pressure of a blower. FIG. 6 is a diagram for explaining the shape and size of the arrangement member. FIG. 6 is a diagram for explaining the arrangement position of the arrangement member. FIG. 6 is a diagram showing the relationship between the arrangement position of the arrangement member and changes in air volume. FIG. 6 is a diagram showing the relationship between frequency and silencing volume for comparative examples 1 to 4 and example 1. FIG. 6 is a diagram showing the relationship between the arrangement position of the arrangement member and silencing volume. FIG. 6 is a diagram showing the relationship between the type of arrangement member and changes in air volume. FIG. 10 is a diagram showing the relationship between the flow resistance of a placement member and a change in air volume. FIG. 11 is a diagram showing the relationship between the type of placement member and the amount of silencing volume. FIG. 12 is a diagram showing the relationship between frequency and sound pressure level in Example 7. FIG. 13 is a diagram showing the relationship between frequency and amount of silencing volume in Example 7. FIG. 14 is a diagram for explaining the shape and size of a placement member. FIG. 15 is a diagram for explaining a method of evaluating vortex life. FIG. 16 is a diagram showing the results of vortex life evaluation in a reference example. FIG. 17 is a diagram showing the results of vortex life evaluation in Example 7. FIG. 18 is a diagram showing the results of vortex life evaluation in Example 8.

[0010] The blower of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings. The following embodiment is merely an example provided to facilitate understanding of the present invention and is not intended to limit the present invention. In other words, the configuration of the present invention may be modified or improved from the following embodiment without departing from the spirit of the present invention. Furthermore, unless otherwise specified, the material and shape of each component used to implement the present invention may be freely set depending on the application of the present invention and the state of the art at the time of implementing the present invention. Furthermore, the present invention includes equivalents thereof.

[0011] Furthermore, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in this specification, "orthogonal," "vertical," and "parallel" are intended to include the range of error acceptable in the technical field to which the present invention belongs. For example, "orthogonal," "vertical," and "parallel" in this specification mean that they are within a range of less than ±10° from the strict "orthogonal," "vertical," and "parallel." The error from the strict "orthogonal," "vertical," and "parallel" is preferably 5° or less, and more preferably 3° or less. Furthermore, in this specification, the meanings of "same" and "identical" may include the range of error generally acceptable in the technical field to which the present invention belongs.

[0012] Furthermore, "sound deadening" in the present invention means to muffle sound, and is a concept that includes both sound insulation and sound absorption. Sound insulation means blocking sound, in other words, not allowing sound to pass through. Sound insulation also includes the reflection of sound (acoustics) and the cancellation of sound (acoustics). Sound absorption means converting sound energy into thermal energy, that is, absorbing sound (acoustics).

[0013] <<Configuration of the Fan According to the Present Embodiment>> A fan (hereinafter, fan 10) according to one embodiment of the present invention (hereinafter, this embodiment) will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the fan 10 includes a fan 20, a casing 30 that houses the fan 20, and a mounting member 40 disposed within the casing 30. The fan 10 is applicable to devices that include a fan, and its use is not particularly limited. The fan 10 may be, for example, a fan provided in an information device such as a personal computer (PC) or a copier, or an outdoor unit (fan) for an air conditioner. The following description will be given on the assumption that the fan 10 is an outdoor unit for an air conditioner disposed in an outdoor space.

[0014] [Fan] The fan 20 is, for example, an axial flow fan, specifically an axial flow fan (propeller fan). The fan 20 blows air in the axial direction of the rotation axis G of the fan 20, and discharges gas taken in from one axial side of the rotation axis G toward the other axial side. The fan 20 is not limited to an axial flow fan such as an axial flow fan, but may be, for example, a diagonal flow fan (diagonal flow fan, etc.) or a cross-flow fan (line flow fan (registered trademark), cross flow fan, etc.). The following description will be given assuming that the fan 20 is an axial flow fan. The term "wind" is not particularly limited and may refer to, for example, an artificial flow of air and gas (airflow). The composition of the air or gas constituting the wind and the ratio of each component are not particularly limited, but the following description will be given assuming that normal air is being blown.

[0015] In the following description, as shown in FIG. 1 , the axial direction of the rotation axis G of the fan 20 is referred to as the “front-rear direction,” the side that takes in air as viewed from the fan 20 is referred to as the “rear side” or “back side,” and the side that discharges air as viewed from the fan 20 is referred to as the “front side” or “front side.” The following description will be based on the assumption that the blower 10 is positioned so that the rotation axis G is horizontal. For ease of explanation, three mutually orthogonal directions as shown in FIG. 1 will be referred to as the “front-rear direction,” the “up-down direction,” and the “left-right direction.” The left-right direction is defined as viewed from the front, and in the following description, the side of a side air intake port 35 (described later) will be referred to as the “left side,” and the side of a machine room 11 (described later) will be referred to as the “right side,” as shown in FIG. 2 . The “front-rear direction,” “up-down direction,” and “left-right direction” are defined solely based on the arrangement of the blower 10 in this embodiment, and their definitions may differ depending on the arrangement of the blower 10.

[0016] 2, the fan 20 includes a motor 21, a shaft 22, and a plurality of blades 23. The motor 21 may be a known electric motor, and rotates the shaft 22. The motor 21 is, for example, cylindrical, and is supported by a support member (not shown) provided inside the casing 30.

[0017] The shaft portion 22 is, for example, cylindrical and is located in front of the motor 21. The shaft portion 22 is attached to, for example, a shaft of the motor 21 that protrudes toward the shaft portion 22, and rotates together with the shaft. The diameter of the shaft portion 22 is, for example, approximately the same as or larger than that of the motor 21. The rotation axis of the shaft portion 22 is located on the same line as the rotation axis G of the fan 20. As shown in FIG. 3 , the rotation axis G of the fan 20 is located at the center of the fan 20 when viewed from the front-to-rear direction.

[0018] The blades 23 are attached to the circumferential surface of the shaft portion 22 and each protrude radially outward from the circumferential surface. The blades 23 are arranged at intervals along the circumferential direction of the shaft portion 22. Note that, although the example shown in FIG. 3 has three blades 23, this is not limitative and the number of blades 23 may be any number depending on the conditions of use. The shape and angle of the blades 23 may be any shape and angle used in known axial flow fans, etc. The angle of the blades 23 refers to the inclination angle of the blades 23 (or their surfaces) relative to the rotation axis G. The blades 23 rotate together with the shaft portion 22 and generate wind (airflow) that travels forward.

[0019] [Casing] As shown in Fig. 1, the casing 30 defines the outer edge of the blower 10, and the fan 20 is disposed inside the casing 30. The shape of the casing 30 is not particularly limited, but in this embodiment, for example, the casing 30 has a rectangular parallelepiped shape that is elongated in the left-right direction. Specifically, as shown in Fig. 1, the casing 30 has multiple (six) walls 31a-31b, 32a-32d, an intake port 33, an exhaust port 34, side intake ports 35, and a shroud 36 (corresponding to a protrusion).

[0020] (Multiple Walls) As shown in FIG. 1 , the multiple (six) walls 31a-31b, 32a-32d are composed of two main surface walls 31a, 31b and four side walls 32a, 32b, 32c, and 32d. In this embodiment, each of the walls 31a-31b, 32a-32d is rectangular. The two main surface walls 31a, 31b are arranged spaced apart in the front-to-rear direction across the fan 20, with the main surface wall 31a located in front (on the front side) of the fan 20 and the main surface wall 31b located in rear (on the back side) of the fan 20. The four side walls 32a, 32b, 32c, and 32d protrude from four sides of the main surface wall 31a and form a cylindrical (rectangular) shape surrounding the fan 20. 2, two of the four side walls 32a, 32b, 32c, and 32d are arranged spaced apart in the left-right direction with the fan 20 in between, and when viewed from the front, the side wall 32a is located on the left side (opposite the machine chamber 11) as viewed from the fan 20, and the side wall 32b is located on the right side (toward the machine chamber 11) as viewed from the front. The remaining two of the four side walls 32a, 32b, 32c, and 32d are arranged spaced apart in the up-down direction with the fan 20 in between, and the side wall 32c is located above the fan 20, and the side wall 32d is located below the fan 20.

[0021] The casing 30 may be constructed by joining adjacent walls of the six walls 31a-31b, 32a-32d together by welding, adhesive, or fastening with screws, or by forming the six walls 31a-31b, 32a-32d integrally (seamlessly). The material of the casing 30 is not particularly limited, and metal materials, resin materials (including reinforced plastic materials), carbon fiber, and the like can be used. Note that in the above description, the side walls constituting the casing 30 are described as being rectangular tubular with four side walls 32a, 32b, 32c, and 32d. However, this is not limited thereto. For example, the casing 30 may be cylindrical with one side wall, or may be rectangular with a number of side walls different from the four side walls.

[0022] (Air Intake Port and Exhaust Port) The air intake port 33 and the exhaust port 34 are located at different positions in the front-rear direction and are spaced apart from each other across the fan 20 in the front-rear direction. As shown in FIG. 2 , the air intake port 33 is provided at one end of the casing 30 in the front-rear direction, more specifically, formed in the rear main wall 31b. The air intake port 33 is an opening that penetrates the main wall 31b in the front-rear direction. On the other hand, the exhaust port 34 is provided at the other end of the casing 30 in the front-rear direction, more specifically, formed in the front main wall 31a. The exhaust port 34 is an opening that penetrates the main wall 31a in the front-rear direction. The shapes (edge ​​shapes) of the air intake port 33 and the exhaust port 34 are not particularly limited and may be, for example, circular, rectangular (square), quadrilateral other than a rectangle, polygonal other than a quadrilateral, or irregular. Note that in this embodiment, the shapes and sizes (opening areas) of the air intake port 33 and the exhaust port 34 are different from each other.

[0023] Specifically, as shown in FIG. 1 , the shape (edge ​​shape) of the air intake 33 is, for example, rectangular, and the center of the air intake 33 is, for example, aligned with the rotation axis G of the fan 20. The vertical length and horizontal width of the air intake 33 are, for example, equal to or greater than the diameter of the fan 20. Note that the "diameter of the fan 20" refers to the diameter of an imaginary circle traced by the trajectories of the leading ends of the blades 23 when the fan 20 rotates. As shown in FIG. 1 , the shape (edge ​​shape) of the exhaust vent 34 is, for example, circular, and the center of the exhaust vent 34 is, for example, aligned with the rotation axis G of the fan 20. The diameter of the exhaust vent 34 is, for example, equal to or greater than the diameter of the fan 20. For example, a lattice-shaped grill (not shown) is attached to the exhaust vent 34.

[0024] (Side Air Intake Port) As shown in FIG. 1 , the side air intake port 35 is provided at one end of the casing 30 in the left-right direction. More specifically, the side air intake port 35 is formed in the left side wall 32a of the casing 30. The side air intake port 35 is an opening that penetrates the side wall 32a in the left-right direction. The shape (edge ​​shape) of the side air intake port 35 is not particularly limited and may be, for example, a circle, a rectangle (square), a quadrangle other than a rectangle, a polygon other than a quadrangle, or an irregular shape. In this embodiment, the shape (edge ​​shape) of the side air intake port 35 is, for example, a rectangle that is long in the vertical direction, as shown in FIG. 1 . The center of the side air intake port 35 in the vertical direction is located at the same height as, for example, the rotation axis G of the fan 20. The length of the side air intake port 35 in the front-rear direction is longer than the length of the fan 20 in the front-rear direction. In the example shown in FIG. 2 , the length is longer than the distance from the front end of the shaft portion 22 to the rear end of the motor 21.

[0025] Furthermore, as shown in Fig. 2, at least a portion of the side air intake port 35 overlaps with the fan 20 when viewed from the left-right direction. In the example shown in Fig. 2, the side air intake port 35 overlaps with a portion of the blades 23 of the fan 20, specifically, with the rear portion of the blades 23 in the front-to-rear direction, when viewed from the left-to-right direction. In other words, when the fan 20 rotates, a portion of the blades 23 (the rear portion) passes through an area surrounded by the edges of the side air intake port 35 when viewed from the left-to-right direction.

[0026] (Shroud) As shown in FIG. 2 , the shroud 36 is provided at one end (main surface wall 31 a) of the casing 30 in the front-rear direction and protrudes from the edge of the exhaust port 34 toward the inside of the casing 30 (the rear side in the front-rear direction). The shroud 36 is cylindrical and surrounds the fan 20. In this embodiment, the tip 36 a of the shroud 36 extends to, for example, the center of the blades 23 in the front-rear direction. In other words, the shroud 36 surrounds a portion of the blades 23. However, this is not limited thereto, and the shroud 36 may surround, for example, the entire blades 23 or the entire fan 20 including the blades 23. The space surrounded by the shroud 36 will be referred to below as the “internal space S1.” In this embodiment, a portion of the blades 23 of the fan 20 is located in the internal space S1.

[0027] 2 , the shroud 36 protrudes further toward the intake port 33 in the front-rear direction than the end of the side intake port 35 on the exhaust port 34 side. That is, when viewed from the left-right direction, at least a portion of the shroud 36 overlaps with the side intake port 35. However, this is not limiting, and for example, the shroud 36 may not protrude further than the end of the side intake port 35 on the exhaust port 34 side in the front-rear direction, and the shroud 36 may not overlap with the side intake port 35 when viewed from the left-right direction.

[0028] The shroud 36 has a cross-sectional size that is larger at both ends than at the center in the front-rear direction. More specifically, the shroud 36 has a shape in which the cross-sectional size increases from the center toward each end, e.g., a bell-mouth shape. The term "cross-section" here refers to a cross-section perpendicular to the front-rear direction, and this applies throughout the following description. The cross-sectional shape of the shroud 36 is not particularly limited and may be, for example, a circle, a rectangle (square), a quadrangle other than a rectangle, a polygon other than a quadrangle, or an irregular shape. In this embodiment, the cross-sectional shape of the shroud 36 is circular corresponding to the circular edge of the exhaust port 34. In other words, the shroud 36 is cylindrical. Note that in this embodiment, the center of the shroud 36 coincides with the center of the fan 20 when viewed from the front-rear direction. More specifically, the cross-sectional size of the shroud 36 is largest at both ends in the front-rear direction, and the cross-sectional size is, for example, approximately the same as the size of the exhaust port 34. The cross-sectional sizes of both ends of the shroud 36 in the front-rear direction may be the same or different from each other. On the other hand, the cross-sectional size of the shroud 36 is smallest at the center in the front-rear direction, and this cross-sectional size is at least larger than the cross-sectional size corresponding to the diameter of the fan 20.

[0029] The shroud 36 may be joined to the main surface wall 31 a by welding, adhesive, or fastening with screws or the like, or may be formed integrally (seamlessly) with the casing 30. The material of the shroud 36 is not particularly limited, and metal materials, resin materials (including reinforced plastic materials), carbon fiber, and the like can be used.

[0030] Here, as shown in FIG. 3 , the space between the cylindrical shroud 36 and the four side walls 32 a to 32 d is defined as the "target space Ts." More specifically, the "target space Ts" is the space surrounded by the casing 30, which is closer to the exhaust port 34 than the tip 36 a of the shroud 36 when viewed from the top-bottom direction as shown in FIG. 2 (i.e., the space closer to the exhaust port 34 than the target line U), and corresponds to the space surrounded by the shroud 36 and the four side walls 32 a to 32 d when viewed from the front-to-back direction as shown in FIG. 3 . Note that in this embodiment, the target space Ts is limited to the space closer to the fan 20 than a partition wall 37 located between the fan 20 and a machine chamber 11 (described later), and the space closer to the machine chamber 11 than the partition wall 37 does not fall under the target space Ts.

[0031] In addition to the fan 20 and a mounting member 40 (described later), a machine chamber 11 and a heat exchanger (not shown) are also disposed within the casing 30. As shown in FIG. 2 , the machine chamber 11 is disposed to the right of the fan 20 (the space on the opposite side of the partition wall 37 from the fan 20) when viewed from the front, and a compressor (not shown) and other components are disposed in the machine chamber 11. The heat exchanger (not shown) is, for example, adjacent to the intake port 33 and the side intake port 35 from the inside of the casing 30 and extends from the intake port 33 to the side intake port 35. The heat exchanger is not particularly limited, and any known heat exchanger may be used, such as a fin-and-tube heat exchanger or a parallel-flow heat exchanger.

[0032] [Location Member] The location member 40 is located in the target space Ts, and as shown in Fig. 3, is located at least at a position adjacent to a point 36b of the shroud 36 that is closest to the side air intake port 35 when viewed from the front-to-rear direction. The "point 36b" refers to the point on the shroud 36 where, when an imaginary line perpendicular to the side air intake port 35 is extended from the side air intake port 35 to the shroud 36, the length of the imaginary line is shortest when viewed from the front-to-rear direction. In this embodiment, the left end of the shroud 36 (when viewed from the front) corresponds to the point 36b.

[0033] 3, the positioning member 40 extends along the outer periphery (outer periphery) of the cylindrical shroud 36 over a predetermined range (angular range) in the circumferential direction of the shroud 36. When viewed from the front-to-rear direction, for example, the positioning member 40 may be arranged around the center of the shroud 36 at an angle of preferably −20° to +20°, more preferably −60° to +60°, and even more preferably −90° to +90°, with the direction of an imaginary line extending from the center of the shroud 36 (the center of the fan 20) to point 36b being set as 0°. Note that the “+” and “−” indicate the direction of rotation around the center of the shroud 36 from the imaginary line extending in the 0° direction, with one indicating clockwise and the other indicating counterclockwise.

[0034] As shown in FIG. 3 , the end of the positioning member 40 on the shroud 36 side in the left-right direction (the right end) curves and extends along the periphery of the shroud 36 when viewed from the front-rear direction, and is adjacent to the shroud 36 and, in this embodiment, is in contact with the shroud 36. However, as described above, the shroud 36 has a shape in which the cross-sectional size increases from the center of the shroud 36 toward each of its ends in the front-rear direction, as shown in FIG. 2 . On the other hand, as shown in FIG. 2 , the positioning member 40 extends in the front-rear direction from the base end (the position on the inner surface of the main surface wall 31 a) of the shroud 36 to the tip 36 a of the shroud 36 while maintaining a constant cross-sectional size. Therefore, strictly speaking, the positioning member 40 contacts the tip 36 a and the base end of the shroud 36, but does not contact the central portion of the shroud 36 (portions other than the tip 36 a and the base end), and a space is formed between the positioning member 40 and the shroud 36. In this way, the space between the positioning member 40 and the shroud 36 is referred to as "space S2." The space S2 can also be said to be part of the target space Ts. However, without being limited to this, for example, the cross-sectional shape of the positioning member 40 may change in the front-rear direction in response to a change in the cross-sectional shape of the shroud 36 in the front-rear direction, in which case the space S2 may not be formed.

[0035] 2, the left end (the end opposite the shroud 36) of the positioning member 40 is adjacent to the end (i.e., the side wall 32a) of the casing 30 on the side of the side intake port 35, and in this embodiment, is in contact with the side wall 32a. Note that the positioning member 40 does not have to be in contact with the side wall 32a, and for example, there may be a predetermined gap between the positioning member 40 and the side wall 32a in the left-right direction.

[0036] As described above, the positioning member 40 extends in the front-rear direction from the base end to the tip 36a of the shroud 36. Therefore, the end of the positioning member 40 on the exhaust port 34 side in the front-rear direction is adjacent to the end of the casing 30 on the exhaust port 34 side (i.e., the main surface wall 31a), as shown in Fig. 2, and in this embodiment, is in contact with the main surface wall 31a. Note that the positioning member 40 does not have to be in contact with the main surface wall 31a, and for example, there may be a predetermined gap between the positioning member 40 and the main surface wall 31a in the front-rear direction.

[0037] 2, a surface 41 extending from the side air intake port 35 toward the tip 36a of the shroud 36 is located at the end of the arrangement member 40 on the intake port 33 side in the front-rear direction. This surface 41 is a plane perpendicular to the front-rear direction (the axial direction of the rotation axis G) and is located at the same position in the front-rear direction as the tip 36a of the shroud 36. In other words, the surface 41 is parallel to the tip 36a (end face) of the shroud 36 and is located on the same imaginary plane as the tip 36a (end face).

[0038] 2, the positional relationship between the positioning member 40 and the side air intake port 35 shows that the positioning member 40 extends further toward the air intake port 33 in the front-to-rear direction than the end of the side air intake port 35 on the exhaust port 34 side. In other words, the positioning member 40 blocks a portion of the side air intake port 35 (the portion on the exhaust port 34 side).

[0039] The placement member 40 is made of, for example, at least one of an impermeable material and a sound-absorbing material.

[0040] (Impermeable Material) The impermeable material is made of at least one of, for example, a metal material, a resin material (including a reinforced plastic material), a carbon fiber, and an independent foam material.

[0041] Examples of metal materials include aluminum, titanium, magnesium, tungsten, iron, steel, chromium, chromium molybdenum, nichrome molybdenum, copper, stainless steel, and alloys thereof.

[0042] Examples of resin materials include acrylic resin, polymethyl methacrylate, polycarbonate, polyamidoide, polyarylate, polyetherimide, polyacetal, polyetheretherketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate, polyimide, ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), polypropylene, and triacetyl cellulose. The resin material may also be a reinforced plastic material, such as carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics (GFRP). Rubbers such as natural rubber, chloroprene rubber, butyl rubber, EPDM (ethylene propylene diene rubber), and silicone rubber, as well as rubbers containing cross-linked structures of these, may also be used as the positioning member 40.

[0043] Closed-cell materials are foamed materials with closed cells, which are structures containing air. Examples of closed-cell materials include closed-cell polyurethane, closed-cell polystyrene, closed-cell polypropylene, closed-cell polyethylene, and closed-cell rubber sponge.

[0044] (Sound-absorbing material) The sound-absorbing material is a breathable material and is composed of a porous material that absorbs sound by converting sound energy into thermal energy. Examples of sound-absorbing materials include open-cell foam sound-absorbing materials and fiber-based sound-absorbing materials. Examples of foam sound-absorbing materials include foamed urethane foam such as Calmflex (registered trademark) F from Inoac Corporation and urethane foam from Hikarisha, soft urethane foam, sintered ceramic particles, phenol foam, melamine foam, insulation board, and polyamide foam.

[0045] Examples of fiber-based sound-absorbing materials include microfiber nonwoven fabrics such as Thinsulate from 3M, polyester nonwoven fabrics such as White Qion (registered trademark) from Tokyo Bouon Co., Ltd. and QonPET (registered trademark) from Bridgestone KBG (including those with a two-layer structure having a thin, high-density nonwoven fabric on the front side and a low-density nonwoven fabric on the back side), plastic nonwoven fabrics such as acrylic fiber nonwoven fabric, natural fiber nonwoven fabrics such as wool and felt, meltblown nonwoven fabric, metal nonwoven fabric, glass nonwoven fabric, floor mats, and carpets.

[0046] The flow resistance of the fiber-based sound-absorbing material is 700 Pa·S / m ２ It is preferable that the viscosity is 1000 Pa·S / m or more. ２ More preferably, it is 1400 Pa·S / m or more. ２ The flow resistance of the fiber-based sound-absorbing material will be described in more detail in the Examples section below.

[0047] As other sound-absorbing materials, in addition to those mentioned above, various sound-absorbing materials can be used, such as sound-absorbing materials made of materials containing minute air particles, for example, glass wool, rock wool, gypsum board, wood wool cement board, and sound-absorbing materials made of nanofiber fibers, etc. Examples of nanofiber fibers include silica nanofibers and acrylic nanofibers such as XAI manufactured by Mitsubishi Chemical Corporation.

[0048] Here, in the internal space (such as a sealed space or a semi-sealed space) of the casing 30, when a placement member 40 made of a sound-absorbing material is placed adjacent to a wall (main surface wall 31a) of the casing 30 as shown in FIG. 2 , an interference effect can be exerted that depends on both the distance Ds between the main surface wall 31a and a surface 41 (the surface opposite the main surface wall 31a) of the placement member 40 and the characteristics of the sound-absorbing material that constitutes the placement member 40. Note that, as shown in FIG. 2 , the "distance Ds" corresponds to the distance between the inner surface of the main surface wall 31a and the surface 41 of the placement member 40. The thickness (length in the front-to-rear direction) of the placement member 40 may be the same as the distance Ds or may be smaller than the distance Ds. Note that, when the thickness of the placement member 40 is smaller than the distance Ds, the placement member 40 is placed with a gap between it and the main surface wall 31a. The interference effect can generate a new attenuation peak or shift the attenuation peak to a lower frequency. By utilizing this interference effect, it is possible to design a filter so that the silencing peak corresponds to the target frequency for silencing.

[0049] The characteristics (parameters) of the sound-absorbing material include, for example, flow resistance for fiber-based sound-absorbing materials, and Biot parameters such as porosity and permeability for foam-based sound-absorbing materials. As an example, the target frequency for sound silencing is set to 500 to 1000 Hz, the thickness of the sound-absorbing material is set to 7 cm, and the flow resistance is set to 10000 Pa·S / m ２ In this case, the sound absorbing effect at 1000 Hz can be improved. In addition, by providing a surface layer such as a nonwoven fabric on the surface of the sound absorbing material, the reflection at the surface of the sound absorbing material increases, and as a result, the interference effect can be improved. This can further improve the sound absorbing effect and promote a shift of the sound absorbing peak to the lower frequency side.

[0050] <<Operations and Effects of the Blower According to the Present Embodiment>> In the blower 10 configured as described above, when the fan 20 operates (rotates), air outside the casing 30 enters the casing 30 through the intake port 33 and the side intake port 35 and exchanges heat with a heat exchanger (not shown) (more specifically, with the refrigerant in the heat exchanger). The air after heat exchange is taken in by the fan 20 and discharged to the outside of the casing 30 through the exhaust port 34.

[0051] Generally, the greater the volume of air drawn into the casing of a blower, the less power is required to control the refrigerant temperature. While increasing the fan's rotation speed is one way to increase the volume of air, this method is undesirable because it increases the fan's operating noise. Therefore, the inventors conducted extensive research to increase the volume of air drawn into the casing while maintaining the fan's rotation speed, and obtained the following findings. These findings will be explained with reference to FIGS. 4 and 5 . The blower 100 shown in FIG. 4 is a comparative example of the blower 10, and differs from the blower 10 in that it does not include the positioning member 40. For convenience, components common to the blower 10 will be designated by the same reference numerals as the blower 10.

[0052] In the blower 100, as shown in Fig. 4, when the fan 20 rotates, air outside the casing 30 enters the casing 30 through the air intake port 33 and the side air intake port 35. A portion of the air that enters the casing 30 through the side air intake port 35 reaches the intake surface of the fan 20 (the rear side in the front-to-rear direction of the fan 20) and is taken into the fan 20 together with the air that entered the casing 30 through the air intake port 33. Meanwhile, the rest of the air that entered the casing 30 through the side air intake port 35 travels along the outer peripheral surface of the shroud 36 and enters the space S3 (see Fig. 4) on the side air intake port 35 side of the target space Ts, where it collides with air that enters the casing 30 later through the side air intake port 35, causing turbulence in the air on the side air intake port 35 side of the casing 30. In particular, the inventors have found that wind turbulence increases at a position in the target space Ts adjacent to the portion 36b of the shroud 36 (see FIG. 3).

[0053] Turbulence in the air flow on the side of the side air intake port 35 also causes turbulence in the air entering the casing 30 through the air intake port 33. This turbulence in the air acts as resistance to the flow of air entering the air intake port 33 and the side air intake port 35, resulting in a decrease in the volume of air taken into the casing.

[0054] Therefore, based on the above findings, the inventors discovered that, as a means for suppressing air from entering the target space Ts, which would cause a decrease in airflow, it is possible to dispose a disposing member 40 in the target space Ts, as shown in Fig. 5. This prevents air that has entered the casing 30 through the side air intake port 35 from entering the target space Ts, thereby suppressing wind turbulence within the casing 30. In particular, based on the above findings, the inventors discovered that wind turbulence within the casing 30 can be effectively suppressed by disposing the disposing member 40 in a position adjacent to the portion 36b of the shroud 36 (see Fig. 3).

[0055] As described above, in blower 10, arrangement member 40 is located in target space Ts, and when viewed from the front-to-rear direction, is arranged at least at a position adjacent to portion 36b of shroud 36 that is closest to side intake port 35. This makes it possible to increase the volume of air drawn into casing 30 while suppressing noise caused by fan 20.

[0056] Furthermore, when the wind inside the casing 30 collides with the rotating fan 20 (blades 23), a vortex is generated. In the blower 100 without the arrangement member 40, wind turbulence is large at and around point 36b (see FIG. 3 ) in the circumferential direction of the shroud 36, causing the vortex at and around point 36b to rapidly dissipate within the casing 30. When the vortex dissipates, pressure fluctuations exceeding a predetermined value occur, resulting in noise levels above the allowable level. On the other hand, in the blower 10 of this embodiment, the arrangement member 40 ensures smooth wind flow at and around point 36b. Therefore, the vortex at and around point 36b does not dissipate within the casing 30 but instead flows out of the casing 30 and slowly dissipates outside the casing 30. In other words, the life of the vortex can be extended in the blower 10 compared to the blower 100 without the arrangement member 40. Therefore, in blower 10, the vortex disappears more slowly than in blower 100 that does not include arrangement member 40, so that the pressure fluctuations when the vortex disappears can be reduced, and as a result, noise caused by fan 20 can be suppressed. The above phenomenon will be described in more detail in the Examples section below with reference to Figures 23 to 25.

[0057] Furthermore, when the arrangement member 40 is made of an impermeable material, it is possible to appropriately suppress the air that has entered the casing 30 from the side air intake port 35 from entering the target space Ts. In particular, when the impermeable material is at least one of a metal material and a resin material, it is possible to prevent air from entering the interior of the arrangement member 40, and therefore it is possible to more appropriately suppress the air from entering the target space Ts. Furthermore, when the impermeable material is a closed-cell material, it is possible to suppress the air from entering the target space Ts and to muffle the noise generated by the blower 10.

[0058] Furthermore, when the placement member 40 is made of a sound-absorbing material, it is possible to suppress the intrusion of air into the target space Ts and to appropriately muffle the sound emitted by the blower 10. In particular, when the sound-absorbing material is a fiber-based sound-absorbing material (especially a fiber-based sound-absorbing material with a flow resistance of 1400 Pa·S / m ２In the case where the material is a foam sound-absorbing material, the sound emitted by the blower 10 can be more appropriately silenced.

[0059] As shown in FIG. 2 , a surface 41 extending from the side air intake port 35 toward the leading end 36 a of the shroud 36 is located at the end of the arrangement member 40 on the intake port 33 side in the front-rear direction. This allows the arrangement member 40 to suppress air from entering the target space Ts through the side air intake port 35, while the surface 41 of the arrangement member 40 smoothly guides the air to the intake surface of the fan 20 (the rear side of the fan 20 in the front-rear direction). That is, the arrangement member 40 has the surface 41, which allows it to exhibit a rectifying effect. In particular, the surface 41 is located at the same position as the leading end 36 a of the shroud 36 in the front-rear direction. This prevents a step from occurring between the surface 41 of the arrangement member 40 and the leading end 36 a of the shroud 36. While such a step could cause resistance to the airflow from the surface 41 of the arrangement member 40 to the leading end 36 a of the shroud 36, this embodiment can suppress the occurrence of such a step, thereby achieving an even more rectifying effect.

[0060] Furthermore, the cross-sectional size of the shroud 36 is larger at both ends than at the center in the front-to-rear direction. This shape of the shroud 36 is thought to be more likely to cause turbulence in the target space Ts. In this regard, the blower 10 has the arrangement member 40, which prevents air from entering the target space Ts. Therefore, the shroud 36 having this shape can further demonstrate the effects of the present invention.

[0061] <<Other Embodiments>> In the above embodiment, the arrangement member 40 extends along the outer periphery of the shroud 36 over a predetermined range (e.g., −20° to +20°) in the circumferential direction of the shroud 36. However, this is not limited thereto. For example, as in the blower 10A shown in FIG. 6 , the arrangement member 40A may be arranged in the target space Ts along the outer periphery of the cylindrical shroud 36 over the entire circumferential range of the shroud 36. In the example shown in FIG. 6 , the arrangement member 40A is arranged over the entire target space Ts. This makes it possible to suppress air from entering the target space Ts even in areas of the target space Ts where the arrangement member 40 was not arranged, i.e., in ranges other than the predetermined range (e.g., −20° to +20°) in the circumferential direction of the shroud 36. This further suppresses wind turbulence within the casing 30, thereby suppressing noise from the fan 20 and increasing the volume of air drawn into the casing 30.

[0062] 7, the shroud 36 of the blower 10A may have an opening 36c that communicates the internal space S1 surrounded by the cylindrical shroud 36 with the target space Ts (more specifically, the space S2 surrounded by the arrangement member 40 and the shroud 36). The blower 10A may also include a breathable cover member 36d that covers the opening 36c. The cover member 36d is, for example, a sheet-like member and is adjacent to the opening 36c from at least one of the inside (the internal space S1 side) and the outside (the target space Ts side) of the shroud 36. The cover member 36d may be made of the sound-absorbing material described above, specifically, a porous material such as an open-cell foam sound-absorbing material or a fiber sound-absorbing material. As a result, for example, if the arrangement member 40A is a sound-absorbing material, the sound emitted by the fan 20 can be guided from the internal space S1 to the target space Ts (space S2) through the opening 36c, and the sound can be silenced by the arrangement member 40A located in the target space Ts. Note that the arrangement member 40A may press against the opening 36c from the space S2 side to close the opening 36c.

[0063] In the example shown in FIG. 7 , the opening 36 c is provided in the center of the shroud 36 in the front-rear direction. In other words, it is provided at a position where the cross-sectional size of the shroud 36 is smallest. However, this is not limited thereto, and for example, the opening 36 c may be provided at a position other than the center of the shroud 36 in the front-rear direction. Also, in the example shown in FIG. 7 , the shroud 36 has multiple openings 36 c (two in FIG. 7 ), and the two openings 36 c are spaced apart from each other in the left-right direction. However, this is not limited thereto, and for example, the number of openings 36 c may be one or three or more, and the openings 36 c may be provided at any position in the circumferential direction of the shroud 36. Also, the shape of the opening 36 c may be, for example, a circle, a rectangle (square), a quadrangle other than a rectangle, a polygon other than a quadrangle, or an irregular shape. Also, the opening 36 c may be, for example, an opening (such as an elongated hole) extending along the circumferential direction of the shroud 36.

[0064] In the above embodiment, as shown in FIG. 2 , the surface 41 of the arrangement member 40 is a plane perpendicular to the front-rear direction (axial direction of the rotation axis G). However, this is not limited thereto. For example, as in the blower 10B shown in FIG. 8 , the arrangement member 40B may have a surface 41B. Like the surface 41, the surface 41B is located at the end of the arrangement member 40B on the intake port 33 side in the front-rear direction and extends from the side intake port 35 toward the tip 36a of the shroud 36. However, unlike the surface 41, the surface 41B is a plane inclined in the front-rear direction (axial direction of the rotation axis G). More specifically, the surface 41B extends at an angle from the end of the side intake port 35 on the exhaust port 34 side to the tip 36a of the shroud 36. In the above embodiment, the arrangement member 40 blocks a portion of the side air intake port 35, but in this modification, the arrangement member 40B has the surface 41B, and therefore does not block the side air intake port 35, allowing air to be taken into the casing 30 from the entire area of ​​the side air intake port 35. Furthermore, the surfaces 41 and 41B are not limited to flat surfaces and may be curved surfaces, for example.

[0065] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0066] <Blower> A blower 100 shown in FIG. 4 was prepared. A Daikin room air conditioner outdoor unit (R22ZES7) was used as the blower 100. The fan 20 was a three-blade axial fan with a diameter of 40 cm. The casing 30 of the blower 100 was a rectangular metal box with external dimensions of 285 mm (front-to-back) x 675 mm (left-to-right) x 530 mm (up-to-down) and a plate thickness of 0.5 mm. The air intake 33 was rectangular with external dimensions of 445 mm (left-to-right) x 490 mm (up-to-down). The side air intake 35 was rectangular with external dimensions of 180 mm (front-to-back) x 465 mm (up-to-down). The exhaust vent 34 was circular with an external diameter of 445 mm. The driving rotation speed of the fan 20 was set to 1000 rpm. In this case, the frequency of the rotation noise (NZ noise) of the fan 20 is 50 Hz (3 blades x 1000 rpm ÷ 60 "minutes"). The "N" in "NZ noise" refers to the fan rotation speed, and "Z" refers to the number of blades. In the following evaluation, only the fan 20 was driven, without driving the compressor (not shown) installed in the machine room 11.

[0067] As shown in Figure 9, placement members of different types, placement positions, and sizes were prepared and placed on the blower 100 to produce the blowers of Comparative Examples 1 to 4 and Examples 1 to 9. Note that in the Reference Example, a placement member was not placed on the blower, so it corresponds to the blower 100 itself. The effects of differences in the placement position, type, and size of the placement member on the effects of the present invention were evaluated by comparing the airflow change and silencing volume calculated in Comparative Examples 1 to 4 and Examples 1 to 9. Note that the "size of the placement member" refers to two sizes: a size adjacent to only a portion of the shroud 36 in the circumferential direction, and a size adjacent to the entire circumferential direction of the shroud 36.

[0068] <Regarding Air Volume Changes> As shown in FIG. 10 , an environment for measuring air volume was prepared, and the volume of air discharged from the blower 100 was measured. Specifically, the blower 100 was fixed on a base M1, and an air volume meter M2 was attached to the exhaust port 34 side of the blower 100. More specifically, a connecting member M3 (made of, for example, acrylic resin) was positioned between the blower 100 and the air volume meter M2, connecting them while maintaining airtightness so that the air flowing from the blower 100 to the air volume meter M2 would not leak to the surroundings. A hood air volume meter (Testo 420, hood opening size 61 cm square) manufactured by Testo Co. was used as the air volume meter M2. After operating the fan 20 of the blower 100, the air volume was measured at 1-second intervals for 3 minutes, and the average value was calculated. The value of the air volume change was determined by subtracting the average air volume in the reference example from the average air volume. Note that the air volume change in the reference example was calculated from 0 m ３ / h.

[0069] <Regarding the Silencing Volume> As shown in FIG. 11 , the blower 100 was placed in the center of a soundproof room (which may be a semi-anechoic or anechoic room) whose walls and ceiling were covered with sound-absorbing material, and microphones M4 were placed around the blower 100. The microphones M4 were placed at eight locations at equal intervals (every 45°) around the periphery of the blower 100. The microphones M4 were placed at least 1 m away from the center of the fan 20 and at least 1 m away in the height direction from the floor of the soundproof room. Furthermore, for the sound pressures measured by the eight microphones M4, the sound pressures of the eight microphones M4 were each squared, all the squared sound pressures were added together, and the sum was divided by the number of microphones M4 (here, eight) to find the average value Q. This average value Q was then calculated by multiplying the squared sound pressure by 10×log １０ The value calculated by substituting this into the equation (Q) was taken as the sound pressure level. The "muffling volume" corresponds to the difference from the sound pressure level of the reference example. The muffling volume of the reference example is 0 dB.

[0070] <Evaluation of the Influence of the Position of the Arrangement Member on the Effects of the Present Invention> The influence of the position of the arrangement member on the effects of the present invention was evaluated by comparing the change in airflow and the sound deadening volume between Comparative Examples 1 to 4 and Example 1. The type of arrangement member used in Comparative Examples 1 to 4 and Example 1 was sound-absorbing material A shown in FIG. 9 . "Sound-absorbing material A" is a foam-type sound-absorbing material, a coated urethane foam, specifically Calmflex (registered trademark) F4 from INOAC Corporation. Furthermore, in Comparative Examples 1 to 4 and Example 1, the size and shape of the arrangement member correspond to the arrangement member 40 of the above-described embodiment, but the size of the arrangement member is such that it is adjacent to only a portion of the shroud 36 in the circumferential direction, and the shape of the arrangement member is the shape shown in FIG. 12 . Specifically, the shape of the arrangement member is a rectangular parallelepiped member with a notch at a radius R1 of 21 cm cut out on the shroud 36 side in the left-right direction, with the vertical dimension X1 of 16 cm, the maximum horizontal dimension (both ends in the up-down direction) Y1 of 4.5 cm, and the minimum horizontal dimension (center position in the up-down direction) Y2 of 3.5 cm. The distance from one end to the other end of the arrangement member in the front-to-rear direction (thickness) is 6 cm.

[0071] 13, the positions of the arrangement members are different in Comparative Examples 1 to 4 and Example 1, and when viewed from the front in the front-to-rear direction, the arrangement member of Comparative Example 1 is at an upper position P1, the arrangement member of Comparative Example 2 is at an upper left position P2, the arrangement member of Comparative Example 3 is at a lower left position P3, the arrangement member of Comparative Example 4 is at a lower position P4, and the arrangement member of Example 1 (corresponding to arrangement member 40) is at a left position P5 with respect to the shroud 36. Note that the arrangement members arranged at the upper left (position P2) and the lower left (position P3) do not include a position adjacent to the portion of the shroud 36 closest to the side intake port 35 (i.e., position P5) when viewed from the front-to-rear direction, and do not correspond to the configuration of the present invention.

[0072] 14 is a diagram showing the relationship between the arrangement position of the arrangement member and the change in air volume. ３ / h, which indicates a larger change in airflow compared to Comparative Examples 1 to 4. FIG. 15 is a diagram showing the relationship between the position of the arrangement member and the amount of silencing sound. Looking at FIG. 15, it is clear that the amount of silencing sound in Example 1 is larger than that in Comparative Examples 1 to 4 at frequencies of 800 Hz to 4 kHz. FIG. 16 is a diagram showing the relationship between the position of the arrangement member and the amount of silencing sound (average value of silencing sound at frequencies of 0.4 Hz to 20 kHz). Note that the "amount of silencing sound [dBA]" shown in the table of FIG. 9 has the same definition as the amount of silencing sound in FIG. 16, i.e., it means the average value of silencing sound at frequencies of 0.4 Hz to 20 kHz. Looking at FIG. 16, it is clear that the amount of silencing sound in Example 1 is 0.41 dBA, which is larger than that in Comparative Examples 1 to 4.

[0073] <Evaluation of the Influence of Different Types of Arrangement Member on the Effects of the Present Invention> The influence of different types of arrangement member on the effects of the present invention was evaluated by comparing the change in airflow and the sound deadening volume in Examples 1 to 7. The size and shape of the arrangement member in Examples 2 to 7 were the same as in Example 1 (see FIG. 12 ). However, the distance (thickness) from one end to the other end of the arrangement member in the front-to-rear direction was 6 cm in Examples 2 to 6, the same as in Example 1, but 7 cm in Example 7. In all Examples 1 to 7, the arrangement member was positioned at position P5 on the left side of the shroud 36 when viewed from the front in the front-to-rear direction (see FIG. 13 ). The arrangement member (sound-absorbing material B) in Example 2 was a foam-based sound-absorbing material, specifically urethane foam, specifically Calmflex (registered trademark) F2 from Inoac Corporation. The arrangement member (sound-absorbing material C) in Example 3 was a fibrous sound-absorbing material, specifically a polyester fiber-based sound-absorbing material, specifically a micromat (without a nonwoven fabric surface layer) manufactured by Taihei Felt Co., Ltd. The flow resistance of the sound absorbing material C is 1400 Pa·s / m ２ "Flow resistance" was calculated by measuring the normal incidence sound absorption coefficient of the sound absorbing material and fitting it using the known Miki model. The flow resistance of the following sound absorbing materials D and E was also calculated in a similar manner. Note that sound absorbing materials C and E were configured without a surface nonwoven fabric layer so that the normal incidence sound absorption coefficient could be measured.

[0074] The placement member (sound-absorbing material D) of Example 4 is a fiber-based sound-absorbing material made of polyester fiber, specifically White Qion (registered trademark) manufactured by Tokyo Bouon Co., Ltd. The placement member (sound-absorbing material E) of Example 5 is a fiber-based sound-absorbing material made of polyester fiber, specifically QonPET (registered trademark) manufactured by Bridgestone KBG (without a surface nonwoven fabric layer). The placement member (sound-absorbing material F) of Example 6 is a fiber-based sound-absorbing material made of polyester fiber, specifically QonPET (registered trademark) manufactured by Bridgestone KBG (with a surface nonwoven fabric layer). The placement member of Example 7 is constructed by preparing an acrylic resin plate (thickness 3 mm) and joining multiple plates cut to a predetermined shape and size from the plate.

[0075] Fig. 17 is a diagram showing the relationship between the type of arrangement member and the change in air volume. Looking at Fig. 17, it can be seen that the change in air volume was 5 m ３ / h or more, and the air volume change value was greater than that of Comparative Examples 1 to 4. In particular, in Examples 1 and 7, the air volume change was 9 m ３ / h, which was found to be larger than those of Examples 2 to 6. The average air volume measured by the air volume meter M2 in Example 7 was 1,824 m ３ / h, and in the reference example, 1815 m ３ / h.

[0076] Figure 18 shows the relationship between flow resistance and change in air volume. As mentioned above, flow resistance was calculated for sound absorbing materials C to E. Looking at Figure 18, the flow resistance was 1400 Pa·s / m ２ In the above cases, the change in air volume is 6 m ３ / h or more. ２ ~1400Pa・s / m ２ The flow resistance was calculated as 700 Pa·S / m. ２ In the above cases, the change in air volume is 3m ３ / h or more, and the flow resistance is 1000 Pa·S / m ２ In the above cases, the change in air volume is 4.5 m ３ / h or more.

[0077] 19 is a diagram showing the relationship between the type of arrangement member and the amount of attenuation (average value of the amount of attenuation from 0.4 Hz to 20 kHz). As can be seen from FIG. 19, the amount of attenuation is 0.28 dBA or more in all of Examples 1 to 7, and in particular, the amount of attenuation in Example 1 is 0.41 dBA, which is greater than that in Examples 2 to 7.

[0078] Figures 20 and 21 are diagrams illustrating in more detail the placement member (made of acrylic resin) of Example 7. Figure 20 is a diagram showing the relationship between frequency and sound pressure level in Example 7, and Figure 21 is a diagram showing the relationship between frequency and silencing volume in Example 7. Looking at Figure 21, it is clear that there is a silencing effect in a wide band from 400 to 4 kHz (although not shown, it is actually 400 to 20,000 Hz).

[0079] <Evaluation of the Influence of Differences in Size of the Arrangement Element on the Effects of the Present Invention> The size of the arrangement element was evaluated by comparing the change in airflow and the sound deadening volume of Examples 1, 7, and 9. The arrangement elements of Examples 1 and 7 have been described above, so a detailed description is omitted. The arrangement element of Example 8 is the same as Example 1 in that it is composed of sound-absorbing material A, specifically, a foam-type sound-absorbing material, a coated urethane foam, and Calmflex (registered trademark) F4 from INOAC Corporation. However, the shape and size of the arrangement element of Example 8 are different from those of Example 1, specifically, corresponding to arrangement element 40A shown in FIG. 6. The size of the arrangement element of Example 8 is such that it is adjacent to the entire circumferential extent of the shroud 36. Furthermore, as shown in FIG. 22, the shape of the arrangement element of Example 8 is such that a circular opening with a radius R2 = 22 cm, which corresponds to the radius of the shroud 36, is provided in the center of the arrangement element, and the outer dimensions in the up-down direction are X2 = 53 cm and the outer dimensions in the left-right direction are Y3 = 44.5 cm. The distance (thickness) from one end to the other end of the placement member in the front-rear direction is 7 cm.

[0080] The positioning member of Example 9 is the same as that of Example 7 in that it is made of acrylic resin. However, the shape and size of the positioning member of Example 9 are different from those of Example 7 and, like Example 8, correspond to positioning member 40A shown in FIG. 6 . The size of the positioning member of Example 9 is a size that is adjacent to the entire circumferential range of the shroud 36. Furthermore, as shown in FIG. 22 , the shape of the positioning member of Example 9 is such that a circular opening with a radius R2 = 22 cm, which corresponds to the radius of the shroud 36, is provided in the center of the positioning member, and the outer dimensions in the up-down direction are X2 = 49 cm and Y3 = 43 cm. Furthermore, the distance (thickness) from one end to the other end of the positioning member in the front-to-rear direction is 7 cm.

[0081] The volume of the placement member in Example 8 is larger than that in Example 9 because the placement member in Example 8 is made of a sound-absorbing material and is easily deformed. In other words, by configuring the placement member in Example 8 to be larger in size than the space to be placed, it is possible to reduce the gap between the placement member and the shroud 36 and the gap between the placement member and the wall of the casing 30. By reducing these gaps, it is possible to further suppress air from entering the target space Ts. However, even in the placement member in Example 8 made of acrylic resin, a sound-absorbing material may be placed separately from the placement member in the gap between the placement member and the shroud 36 and the gap between the placement member and the wall of the casing 30, and by reducing these gaps, it is possible to further suppress air from entering the target space Ts.

[0082] 9, the change in air volume was 9 m ３ / h, whereas in Example 8 it was 20 m ３ / h, and in Example 9 it was 19 m ３ / h. Therefore, the change in air volume was larger when the arrangement member was adjacent to the entire circumferential range of the shroud 36 than when the arrangement member was adjacent to only a partial circumferential range of the shroud 36. Also, referring to FIG. 9 , the silencing volume was 0.11 dBA in Example 1 and 0.40 dBA in Example 7, while it was 1.6 dBA in Example 8 and 1.13 dBA in Example 9. Therefore, the silencing volume was larger when the arrangement member was adjacent to the entire circumferential range of the shroud 36 than when the arrangement member was adjacent to only a partial circumferential range of the shroud 36.

[0083] <Regarding Vortex Life Evaluation> Next, an evaluation of the life of vortices generated within the casing 30 (hereinafter referred to as "vortex life evaluation") was performed. The results of the vortex life evaluation will be described below with reference to FIGS. 23 to 26 . For the vortex life evaluation, particle image velocimetry (PIV) was used to visualize the behavior of vortices (airflow) at and near the portion 36b of the shroud 36. More specifically, as shown in FIG. 23 , a blower 100, a light source M5, a high-speed camera M6, and smoke M7 (air containing fine particles) were prepared. The light source M5 and the high-speed camera M6 were installed on the front side of the blower 100 in the longitudinal direction. The fan 20 of the blower 100 was operated at 1000 rpm, and then smoke M7 was introduced into the casing 30. In this state, light M8 emitted from light source M5 was irradiated onto location 36b of blower 100 and smoke M7 in the vicinity thereof, and scattered light M9 from smoke M7 was photographed with high-speed camera M6. As shown in FIG. 23 , light M8 was a sheet-like light shining along a virtual plane perpendicular to the up-down direction (in other words, a virtual plane extending in the front-to-back and left-to-right directions). A high-brightness LED (Light Emitting Diode) light source, specifically, a UFLS-75-08W-UT manufactured by U-TECHNOLOGY, was used as light source M5. A FASTCAM Mini UX100 manufactured by Photron was used as high-speed camera M6. The photographing speed of high-speed camera M6 was 2500 fps (0.4 msec). In this evaluation, the largest vortex among one or more vortices generated at location 36b and its vicinity was the object of observation (evaluation). Furthermore, the timing at which the evaluation begins (i.e., the time point of "0 msec") is set to the timing at which one of the multiple blades 23 is used as the reference blade, and the reference portion of that blade 23 (e.g., the edge of the blade 23) passes a predetermined point in the circumferential direction of the shroud 36.

[0084] FIG. 24 shows the results of the vortex life evaluation for the reference example (blower 100 without a placement member), and is a photograph taken with a high-speed camera M6 of the vortex (largest vortex) at 0.4 msec and 11.6 msec. As can be seen from FIG. 24, in the reference example, the vortex that was visible at 0.4 msec had disappeared at 11.6 msec. FIG. 25 shows the results of the vortex life evaluation for Example 7, and is a photograph taken with a high-speed camera M6 of the vortex (largest vortex) at 0.4 msec and 13.6 msec. As can be seen from FIG. 25, in the reference example, the vortex that disappeared at 11.6 msec remained at 13.6 msec. in Example 7. 26 shows the results of the vortex life evaluation in Example 8, and is a photograph of the vortex (largest vortex) at 0.4 msec and 11.6 msec taken with high-speed camera M6. As can be seen from FIG. 26, the vortex disappeared at 11.6 msec in the Reference Example, but remained at 11.6 msec in Example 7. Thus, it was found that the vortex life was longer in Examples 7 and 8 than in the Reference Example.

[0085] The effects of the present invention are clear from the evaluation results described above.

[0086] 10, 10A, 10B, 100 Blower 11 Machine room 20 Fan 21 Motor 22 Shaft 23 Blade 30 Casing 31a, 31b Main surface wall 32a, 32b, 32c, 32d Side wall 33 Air intake 34 Exhaust outlet 35 Side air intake 36 Shroud (protrusion) 36a Tip 36b Location 36c Opening 36d Cover member 37 Partition wall 40, 40A, 40B Positioning member 41, 41B Surface Ds Distance G Rotation axis M1 Base M2 Air flow meter M3 Connecting member M4 Microphone M5 Light source M6 High-speed camera M7 Smoke M8 Light M9 Scattered light P1, P2, P3, P4, P5 Position S1 Internal space S2, S3 Space Ts Target space U Target line

Claims

1. A blower comprising: a fan; a casing that houses the fan; and a positioning member that is arranged within the casing, wherein the casing includes an intake port and an exhaust port that are arranged apart from each other on either side of the fan in the axial direction of the fan's rotation shaft, a side wall that surrounds the fan, a side intake port formed in the side wall, and a cylindrical protrusion that protrudes from the edge of the exhaust port toward the inside of the casing, and the positioning member is located in a target space between the protrusion and the side wall, and is arranged at least in a position adjacent to the part of the protrusion that is closest to the side intake port when viewed from the axial direction.

2. The blower according to claim 1, wherein the placement member is made of an impermeable material.

3. The blower according to claim 2, wherein the impermeable material is at least one of a metal material and a resin material.

4. The blower of claim 2, wherein the impermeable material is a closed-cell material.

5. The blower according to claim 1, wherein the placement member is made of a sound-absorbing material.

6. The blower according to claim 5, wherein the sound-absorbing material is a fiber-based sound-absorbing material.

7. The flow resistance of the fiber-based sound-absorbing material is 700 Pa·s / m ２ The blower according to claim 6 .

8. The blower according to claim 5, wherein the sound-absorbing material is a foam-based sound-absorbing material.

9. The blower according to claim 1, wherein a surface extending from the side air intake port toward the tip of the protrusion is located at the end of the arrangement member on the air intake port side in the axial direction.

10. The blower of claim 9, wherein said surface is at the same position in the axial direction as the tip of said protrusion.

11. The blower according to claim 1, wherein the placement member is placed in the target space along the outer periphery of the cylindrical protrusion, over the entire circumferential range of the protrusion.

12. A blower as described in claim 1, wherein the protrusion has an opening that connects the internal space surrounded by the cylindrical protrusion with the target space, and further comprising a breathable cover member that covers the opening.

13. The blower according to claim 1, wherein the cross-sectional size of the protrusion is larger at both ends than at a center portion in the axial direction.

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