WO2024038573A1

WO2024038573A1 - Blower fan, multi-blade centrifugal blower, and air-conditioning indoor unit

Info

Publication number: WO2024038573A1
Application number: PCT/JP2022/031326
Authority: WO
Inventors: 弘恭林; 拓矢寺本; 圭一山本; 一也道上; 貴宏山谷; 隼治植田
Original assignee: 三菱電機株式会社
Priority date: 2022-08-19
Filing date: 2022-08-19
Publication date: 2024-02-22
Also published as: TW202409429A

Abstract

This blower fan comprises a disc-shaped main plate, a plurality of blades that are installed on the periphery of the main plate, and an annular side plate that faces the main plate and fixes the ends of the plurality of blades on the opposite side from the main plate. Each of the plurality of blades has an engaging part that protrudes and is fixed to the side of the side plate that is opposite from the side where the main plate is installed, the engaging part forming a fixed portion between each of the plurality of blades and the side plate. The engaging part has a curved-surface section that forms a convex curved surface toward the direction in which the plurality of blades rotate.

Description

Blower fans, multi-blade centrifugal blowers, and air conditioning indoor units

The present disclosure relates to a blower fan, a multi-blade centrifugal blower, and an air conditioning indoor unit.

A conventional multi-blade centrifugal blower includes a fan having a disc-shaped main plate, a plurality of blades installed on the peripheral edge of the main plate, and a side plate that fixes the ends of the blades (for example, Patent Document 1 reference).

Japanese Patent Application Publication No. 8-247094

However, in the fan of the multi-blade centrifugal blower disclosed in Patent Document 1, the blades and the side plates are separate parts. Like the multi-blade centrifugal blower disclosed in Patent Document 1, when the blades are fixed to the fan, side plates are often provided on the upper part of the blades for reasons of strength or ease of design. The blower fan of Patent Document 1 is made of paper impregnated with synthetic resin, but in the case of a large blower fan that requires high rotation, strong metal fans are required because the fan needs to be strong during rotation. is used. In addition, in the case of metal fans, when the blades are fixed to the side plate, the protrusions of the blades provided for fixation protrude from the side plate, and the airflow flowing on the side plate interferes with the protrusions, resulting in noise generated from the fan. may increase, and the aerodynamic characteristics of the fan may deteriorate.

The present disclosure is intended to solve the above-mentioned problems, and provides a blower fan, a multi-blade centrifugal blower, and an air conditioning indoor unit in which noise generated from the fan is suppressed and the aerodynamic characteristics of the fan are improved. It is something to do.

A blower fan according to the present disclosure includes a disc-shaped main plate, a plurality of blades installed on the peripheral edge of the main plate, and an end portion of the plurality of blades opposite to the main plate that faces the main plate. an annular side plate to be fixed; each of the plurality of wings is fixed in a protruding manner on the side opposite to the installation side of the main plate; and an engagement member forming a fixed part between each of the plurality of wings and the side plate; The engagement portion has a curved surface portion that forms a convex curved surface toward the rotation direction of the plurality of blades.

A multi-blade centrifugal blower according to the present disclosure includes the blower fan described above, a peripheral wall formed in a spiral shape, and at least one side wall having a bell mouth forming a suction port, and the blower fan generates The scroll casing forms a discharge port through which the generated airflow is discharged, and houses a blower fan.

An air conditioning indoor unit according to the present disclosure includes the above multi-blade centrifugal blower and a heat exchanger through which air flowing by the multi-blade centrifugal blower passes.

In the blower fan, multi-blade centrifugal blower, and air conditioning indoor unit according to the present disclosure, each of the plurality of blades is fixed to protrude on the side opposite to the installation side of the main plate of the side plate, and each of the plurality of blades is fixed. It is formed to have an engaging portion that forms a fixed portion between the side plate and the side plate. The engaging portion has a curved surface portion that forms a convex curved surface toward the rotational direction of the plurality of blades. In blower fans and multi-blade centrifugal blowers, by making the engaging part a convex curved surface in the direction of rotation of the fan, airflow flowing on the opposite side of the side plate from the installation side of the main plate is engaged when the fan rotates. It passes smoothly along the curved surface of the part. In blower fans and multi-blade centrifugal blowers, the airflow passes smoothly along the curved surface of the engagement part, and interference of the airflow at the fixed part between the blade and the side plate is suppressed, so the noise generated from the fan is suppressed. The aerodynamic characteristics of the fan are improved.

1 is an external view schematically showing a configuration of a multi-blade centrifugal blower according to Embodiment 1 when viewed parallel to a rotation axis. FIG. 1 is a perspective view of a multi-blade centrifugal blower according to Embodiment 1. FIG. 1 is a perspective view of a blower fan of the multi-blade centrifugal blower according to Embodiment 1. FIG. FIG. 2 is a plan view of the blower fan of the multi-blade centrifugal blower according to the first embodiment. FIG. 2 is an enlarged conceptual diagram of an engaging portion of the multi-blade centrifugal blower according to the first embodiment. FIG. 3 is a perspective view of a blower fan of a multi-blade centrifugal blower according to a second embodiment. FIG. 3 is a plan view of a blower fan of a multi-blade centrifugal blower according to a second embodiment. FIG. 7 is an enlarged view of a blower fan of a multi-blade centrifugal blower according to Embodiment 3; FIG. 7 is a conceptual diagram showing the configuration of an air conditioner according to Embodiment 4. FIG. 7 is a perspective view of an air conditioning indoor unit included in an air conditioner according to Embodiment 4.

Hereinafter, a blower fan, a multi-blade centrifugal blower, and an air conditioning indoor unit according to embodiments will be described with reference to the drawings and the like. Note that in the following drawings including FIG. 1, the relative dimensional relationships, shapes, etc. of each component may differ from the actual ones. In addition, in the following drawings, parts with the same reference numerals are the same or equivalent, and this is common throughout the entire specification. In addition, to facilitate understanding, we use terms that indicate directions (for example, "top", "bottom", "right", "left", "front", "back", etc.), but these notations are as follows: This is only described for convenience of explanation, and does not limit the arrangement or orientation of the device or parts.

Embodiment 1.
[Multi-blade centrifugal blower 1]
FIG. 1 is an external view schematically showing the configuration of a multi-blade centrifugal blower 1 according to Embodiment 1, viewed parallel to the rotation axis RA. FIG. 2 is a perspective view of the multi-blade centrifugal blower 1 according to the first embodiment. The solid line arrow in FIG. 1 indicates the rotation direction R of the blower fan 2, and the broken line arrow indicates the circumferential direction CD of the blower fan 2. Moreover, FIG. 2 explains the external appearance of the multi-blade centrifugal blower 1, and the internal configuration of the multi-blade centrifugal blower 1 is shown in a simplified manner. The basic structure of the multi-blade centrifugal blower 1 will be explained using FIGS. 1 and 2.

The multi-blade centrifugal blower 1 is a device that blows air using centrifugal force generated by the rotation of the blower fan 2, and is, for example, a sirocco fan. The multi-blade centrifugal blower 1 is a double-suction type centrifugal blower in which air is sucked in from both sides of the scroll casing 4 in the axial direction of the imaginary rotation axis RA of the blower fan 2. Note that the multi-blade centrifugal blower 1 is not limited to a double suction type centrifugal blower, but may be a single suction type centrifugal blower in which air is sucked in from one side of the scroll casing 4 in the axial direction of the rotation axis RA. As shown in FIGS. 1 and 2, the multi-blade centrifugal blower 1 includes a blower fan 2 that generates airflow, and a scroll casing 4 that houses the blower fan 2 therein.

(Blower fan 2)
FIG. 3 is a perspective view of the blower fan 2 of the multi-blade centrifugal blower 1 according to the first embodiment. FIG. 4 is a plan view of the blower fan 2 of the multi-blade centrifugal blower 1 according to the first embodiment. 3 is a perspective view of the blower fan 2 seen from below the multi-blade centrifugal blower 1 of FIG. 2, and FIG. 4 is a perspective view of the blower of the multi-blade centrifugal blower 1 seen from the back side of the page of FIG. FIG. 2 is a plan view of a fan 2 for use. Moreover, FIG. 4 is a drawing of the blower fan 2 seen in the axial direction of the rotation axis RA. The blower fan 2 will be explained using FIGS. 1 to 4.

The blower fan 2 is a centrifugal fan. The blower fan 2 is connected to a motor (not shown) having a drive shaft. The blower fan 2 is rotationally driven by a motor, and uses centrifugal force generated by the rotation to forcibly send air outward in the radial direction. The blower fan 2 is rotated by a motor or the like in a rotation direction R indicated by a solid arrow. The blower fan 2 is made of sheet metal. Note that the blower fan 2 is not limited to being made of sheet metal, and may be made of other materials such as resin.

As shown in FIGS. 3 and 4, the blower fan 2 includes a disc-shaped main plate 2a, a plurality of blades 2d installed on the peripheral edge 2a1 of the main plate 2a, and an annular side plate 2c. The blower fan 2 is formed into a bottomed cylindrical shape by a main plate 2a, a plurality of blades 2d arranged on the main plate 2a, and a side plate 2c.

The blower fan 2 has a fan suction port 2e formed in a portion on the side plate 2c side opposite to the main plate 2a in the axial direction of the rotation axis RA. The fan suction port 2e is an opening of the blower fan 2 through which air flows into the blower fan 2, and allows gas to flow into the space surrounded by the main plate 2a and the plurality of blades 2d.

(Main plate 2a)
The main plate 2a is formed into a disk shape, as shown in FIGS. 3 and 4. In the form shown in FIGS. 3 and 4, the main plate 2a is formed in a circular shape when viewed in the axial direction of the rotation axis RA, but it may have a shape other than a circular shape, such as a polygonal shape, for example. The thickness of the main plate 2a may be formed to a constant thickness in the radial direction centered on the rotation axis RA, and the thickness of the main plate 2a may be a constant thickness in the radial direction centered on the rotation axis RA, and the thickness of the main plate 2a is the same as the thickness of the wall from the outer circumference toward the center in the radial direction centered on the rotation axis RA. It may be formed so that it becomes thick.

The main plate 2a is not limited to being composed of a single plate-like member, but may be composed of a plurality of plate-like members fixed together. Further, the main plate 2a may be formed into a flat plate shape, or may have a bent portion. Further, the main plate 2a may have a portion that is inclined with respect to a plane extending in a radial direction centered on the rotation axis RA. Further, the plate surface of the main plate 2a may be formed in a planar shape or may have unevenness.

A boss portion 2b to which the drive shaft of the motor is connected is provided at the center of the main plate 2a. A shaft hole 2b1 into which a motor drive shaft is inserted is formed in the boss portion 2b. The boss portion 2b is formed, for example, in a cylindrical shape, but the shape of the boss portion 2b is not limited to the cylindrical shape. The boss portion 2b may be formed into a columnar shape, for example, a polygonal columnar shape. The main plate 2a is rotationally driven by a motor via the boss portion 2b.

(Side plate 2c)
As shown in FIGS. 3 and 4, the blower fan 2 includes an annular side plate 2c attached to an end of a plurality of blades 2d opposite to the main plate 2a in the axial direction of the rotation axis RA. There is. The side plate 2c is formed in a plate shape, and is formed in an annular shape. The side plate 2c is arranged to face the main plate 2a via a plurality of blades 2d in the axial direction of the rotation axis RA. The side plate 2c is provided at the tip portion 2g of a plurality of blades 2d that protrude from the main plate 2a in the direction of the rotation axis RA. In the axial direction of the rotation axis RA, when the main plate 2a side is defined as the lower side and the side plate 2c side is defined as the upper side, the side plate 2c is provided above the blade 2d.

The side plate 2c fixes the ends of the plurality of blades 2d on the side opposite to the main plate 2a side in the axial direction of the rotation axis RA. That is, the side plate 2c fixes the position of the upper part of the wing 2d, and fixes the plurality of wings 2d. The side plate 2c maintains the positional relationship of the tips of each wing 2d by connecting the plurality of wings 2d. Moreover, the side plate 2c reinforces the strength of the plurality of wings 2d by connecting the plurality of wings 2d. Further, the side plate 2c forms a fan suction port 2e that serves as a gas suction port for the blower fan 2.

As shown in FIG. 3, the side plate 2c includes an annular first side plate 2c1 disposed facing the main plate 2a, and a main plate 2a on the side opposite to the side on which the first side plate 2c1 is disposed with respect to the main plate 2a. and an annular second side plate 2c2 disposed opposite to the second side plate 2c2. Note that the side plate 2c is a general term for the first side plate 2c1 and the second side plate 2c2, and the blower fan 2 has the first side plate 2c1 on one side with respect to the main plate 2a in the axial direction of the rotation axis RA, It has a second side plate 2c2 on the other side.

(wing 2d)
As shown in FIGS. 3 and 4, the plurality of blades 2d are installed on the peripheral edge 2a1 of the main plate 2a. The plurality of blades 2d have one end connected to the main plate 2a, the other end connected to the side plate 2c, and are arranged in a circumferential direction centered on the rotation axis RA. Each of the plurality of wings 2d is arranged between the main plate 2a and the side plate 2c. The plurality of wings 2d are arranged circumferentially around the boss portion 2b, and their base ends are fixed on the surface of the main plate 2a.

The blades 2d are arranged in the circumferential direction CD at a constant interval from each other on the peripheral edge 2a1 of the main plate 2a. Each wing 2d is provided so as to rise from the main plate 2a, and is formed in a plate shape. Each wing 2d is provided so as to stand up almost perpendicularly to the main plate 2a, but the invention is not limited to this, and each wing 2d may be provided at an angle with respect to the vertical direction of the main plate 2a. . As shown in FIG. 3, in the blade 2d, the surface on the rotation direction side is a pressure surface 2d1, and the surface on the opposite side to the rotation direction R is a suction surface 2d2.

As shown in FIG. 3, the base end 2h of the blade 2d is one end of the blade 2d in the axial direction of the rotation axis RA, and is the end on the main plate 2a side. The tip portion 2g of the blade 2d is the other end of the blade 2d in the axial direction of the rotation axis RA, and is the end opposite to the main plate 2a. The base end 2h of the blade 2d is connected to the main plate 2a, and the tip 2g of the blade 2d is connected to the side plate 2c.

The leading edge 24a of the blade 2d is formed by the inner peripheral end 24 of the blade 2d. The inner peripheral end 24 is an end on the inner peripheral side of the blade 2d in a cross section perpendicular to the rotation axis RA, and the leading edge 24a is a part where the inner peripheral end 24 is continuous in the axial direction of the rotation axis RA. A trailing edge 25a of the blade 2d is formed at an outer peripheral end 25. The outer peripheral end 25 is an end on the outer peripheral side of the blade 2d in a cross section perpendicular to the rotation axis RA, and the trailing edge 25a is a part where the outer peripheral end 25 is continuous in the axial direction of the rotation axis RA.

The plurality of blades 2d are provided on both sides of the main plate 2a in the axial direction of the rotation axis RA. As shown in FIG. 3, the blower fan 2 has a first wing section 12a and a second wing section 12b. The first wing section 12a and the second wing section 12b each include a plurality of wings 2d. More specifically, the first wing portion 12a is composed of a plurality of wings 2d arranged between the main plate 2a and the first side plate 2c1. The second wing portion 12b is composed of a plurality of wings 2d arranged between the main plate 2a and the second side plate 2c2.

The first wing portion 12a is arranged on one plate surface side of the main plate 2a, and the second wing portion 12b is arranged on the other plate surface side of the main plate 2a. That is, the plurality of wings 2d are provided on both sides of the main plate 2a in the axial direction of the rotation axis RA, and the first wing part 12a and the second wing part 12b are provided back to back with the main plate 2a interposed therebetween. It is being In addition, in FIG. 3, the first wing part 12a is arranged above the main plate 2a, and the second wing part 12b is arranged below the main plate 2a. However, the first wing section 12a and the second wing section 12b only need to be provided back to back with the main plate 2a in between, and the first wing section 12a is arranged below the main plate 2a, and the first wing section 12a is disposed on the lower side with respect to the main plate 2a. The second wing portion 12b may be disposed above. In the following description, unless otherwise specified, the blade 2d will be described as a general term for the blade 2d that constitutes the first wing section 12a and the blade 2d that constitutes the second wing section 12b.

As shown in FIG. 3, the blower fan 2 has a cylindrical shape with a plurality of blades 2d arranged on a main plate 2a. The blower fan 2 is configured to cause gas to flow into a space surrounded by the main plate 2a and the plurality of blades 2d at a portion on the side plate 2c side opposite to the main plate 2a in the axial direction of the rotation axis RA. A fan suction port 2e is formed. The blower fan 2 has blades 2d and side plates 2c arranged on both sides of a plate surface constituting the main plate 2a, and fan suction ports 2e of the blower fan 2 are formed on both sides of the plate surface constituting the main plate 2a. ing.

Although the blower fan 2 has been described with reference to FIG. 3 as having the first wing section 12a and the second wing section 12b, the blower fan 2 may have a structure having only the first wing section 12a. When the multi-blade centrifugal blower 1 is a single-suction type centrifugal blower, the blades 2d may be provided only on one side of the main plate 2a in the axial direction of the rotation axis RA.

Each of the plurality of wings 2d has an engaging portion 20 that protrudes and is fixed to the opposite side of the side plate 2c from the installation side of the main plate 2a, and forms a fixed part between each of the plurality of wings 2d and the side plate 2c. . That is, the blower fan 2 has a plurality of protruding engaging portions 20, which are fixed portions between each of the plurality of blades 2d and the side plate 2c, in a portion of the side plate 2c on the side opposite to the installation side of the main plate 2a. have Each of the plurality of engaging portions 20 has a curved surface portion 20a that forms a convex curved surface toward the rotation direction R of the plurality of blades 2d.

The plurality of engaging portions 20 are provided at the tip portions 2g of each of the plurality of wings 2d. The engaging portion 20 is a connecting portion between the wing 2d and the side plate 2c. The engaging portion 20 is a fixed portion between the wing 2d and the side plate 2c, and is a portion protruding from the side plate 2c to the side opposite to the main plate 2a. The engaging portion 20 is a protrusion used in manufacturing the blower fan 2. The blower fan 2 is fixed by connecting the blade 2d and the side plate 2c by engaging the engaging portion 20 provided at the tip 2g of the blade 2d with the side plate 2c.

FIG. 5 is an enlarged conceptual diagram of the engaging portion 20 of the multi-blade centrifugal blower 1 according to the first embodiment. FIG. 5 is a conceptual diagram of the engaging portion 20 viewed from the side, and the overall shape of the wing 2d is omitted. The engaging portion 20 will be explained using FIGS. 3 to 5. The engaging portion 20 is formed by a protruding piece provided on the tip end portion 2g side of the main body portion 21 of the wing 2d. The engaging portion 20 is formed into a plate shape. Note that the main body portion 21 of the blade 2d is a portion that mainly generates airflow when the blade 2d rotates. A plurality of through holes 22 are formed in the side plate 2c to respectively fix the plurality of wings 2d.

The plurality of engaging portions 20 are inserted and fixed into the plurality of through holes 22 provided in the side plate 2c, respectively. A portion of the engaging portion 20 that protrudes from the through hole 22 due to the combination of the wing 2d and the side plate 2c is bent toward the rotational direction R of the wing 2d, and is crimped and fixed to the side plate 2c. The engagement portion 20 fixes the blade 2d and the side plate 2c in a crimped state in the blower fan 2.

The curved surface portion 20a forms a convex curved surface toward the rotation direction R. The curved surface portion 20a of the engaging portion 20 is formed by the tip portion 20b of the engaging portion 20. That is, the curved surface portion 20a is an end portion of the engaging portion 20 on the opposite side from the main body portion 21. The curved surface portion 20a is a tip portion in the direction in which the engaging portion 20 is bent. That is, the curved surface portion 20a is formed by the tip portions 20b of the plurality of engaging portions 20 in the rotation direction R. The curved surface portion 20a constitutes a surface facing the rotation direction R. The curved surface portion 20a is formed in a curved shape, for example, in an arc shape when viewed in the axial direction of the rotation axis RA. The curved surface portion 20a is a portion that receives gas and collides with the gas when the blower fan 2 rotates in the rotation direction R.

The blower fan 2 is driven to rotate around the rotation axis RA by being driven by a motor (not shown). As the blower fan 2 rotates, the gas outside the multi-blade centrifugal blower 1 flows through the suction port 5 formed in the scroll casing 4 shown in FIG. 1, which will be described later, and the fan suction port 2e of the blower fan 2. The air is sucked into the space surrounded by the main plate 2a and the plurality of wings 2d. When the blower fan 2 rotates, the air sucked into the space surrounded by the main plate 2a and the plurality of blades 2d passes through the space between the blades 2d and the adjacent blades 2d, and the air flows through the air blower fan 2. 2 in the radial direction.

(Scroll casing 4)
The scroll casing 4 will be explained using FIGS. 1 and 2. The scroll casing 4 houses the blower fan 2 therein, and rectifies the air blown out from the blower fan 2. The scroll casing 4 is a double-suction type casing that has side walls 4a in which suction ports 5 (described later) are formed on both sides of the main plate 2a in the axial direction of the rotation axis RA. The scroll casing 4 is not limited to a double suction type casing, but may be a single suction type casing having a side wall 4a in which a suction port 5 (described later) is formed on one side of the main plate 2a in the axial direction of the rotation axis RA. But that's fine.

The scroll casing 4 has a scroll part 41 and a discharge part 42. The scroll casing 4 has a peripheral wall 4c formed in a spiral shape, and side walls 4a provided on both sides of the blower fan 2 in the axial direction of the rotation axis RA.

(Scroll part 41)
The scroll portion 41 forms an air path that converts the dynamic pressure of the airflow generated by the blower fan 2 into static pressure. The scroll portion 41 includes a side wall 4a that covers the blower fan 2 from the axial direction of the rotation axis RA, and a peripheral wall 4c that surrounds the blower fan 2 from the radial direction of the rotation axis RA of the boss portion 2b. .

Further, the scroll portion 41 has a tongue portion 43 which is located between the scroll portion 41 and the discharge portion 42 and forms a curved surface, and which guides the airflow generated by the blower fan 2 to the discharge port 42a via the scroll portion 41. The internal space of the scroll portion 41 constituted by the peripheral wall 4c and the side wall 4a is a space through which air blown out from the blower fan 2 flows along the peripheral wall 4c.

(Side wall 4a)
In the first embodiment, the scroll casing 4 includes two side walls 4a. The side walls 4a are arranged on both sides of the blower fan 2 in the axial direction of the rotation axis RA. Two side walls 4a arranged on both sides of the blower fan 2 are formed to face each other with a peripheral wall 4c interposed therebetween. A suction port 5 is formed in the side wall 4a so that air can flow between the blower fan 2 and the outside of the scroll casing 4.

The suction port 5 communicates with the fan suction port 2e, and is an air intake port that allows gas to flow into the space surrounded by the main plate 2a and the plurality of blades 2d. The suction port 5 is formed at a position facing the plate surface of the main plate 2a.

As shown in FIG. 2, the scroll casing 4 includes a first side wall 4a1 and a second side wall 4a2 as the side walls 4a. That is, the scroll casing 4 has at least one side wall 4a provided with a bell mouth 3 that forms a suction port 5 that communicates with the space formed by the main plate 2a and the plurality of blades 2d.

The suction port 5 provided in the side wall 4a is formed by the bell mouth 3. That is, the bell mouth 3 forms a suction port 5 that communicates the space outside the scroll casing 4 with the space formed by the main plate 2a and the plurality of blades 2d. The bell mouth 3 rectifies the gas sucked into the blower fan 2 and causes it to flow into the fan suction port 2e of the blower fan 2.

The bell mouth 3 is formed so that the opening diameter gradually decreases from the outside to the inside of the scroll casing 4. The bell mouth 3 is formed to extend in the axial direction of the rotation axis RA. An inner circumferential end forming an inner edge of the bell mouth 3 is located inside the scroll casing 4. Air near the suction port 5 flows smoothly along the bell mouth 3 and efficiently flows into the blower fan 2 from the suction port 5.

(peripheral wall 4c)
The peripheral wall 4c is a wall that guides the airflow generated by the blower fan 2 to the discharge port 42a along the curved wall surface. The peripheral wall 4c is formed in a spiral shape. The peripheral wall 4c is formed such that the distance from the rotation axis RA gradually increases as it advances in the rotation direction R of the blower fan 2, starting from the tongue portion 43. In the rotation direction R of the blower fan 2, the gap between the peripheral wall 4c and the outer periphery of the blower fan 2 increases at a predetermined rate from the tongue portion 43 to the discharge portion 42, and the air flow is The road area is designed to gradually increase in area.

The spiral shape of the peripheral wall 4c includes, for example, a logarithmic spiral, an Archimedean spiral, or a shape based on an involute curve. The inner circumferential surface of the peripheral wall 4c constitutes a curved surface that curves smoothly along the circumferential direction of the blower fan 2 from the tongue portion 43 where the spiral-shaped winding starts to the winding end portion 41b where the spiral-shaped winding ends. . With such a configuration, the air sent out from the blower fan 2 flows smoothly through the gap between the blower fan 2 and the peripheral wall 4c in the direction of the discharge part 42. Therefore, within the scroll casing 4, the static pressure of air increases efficiently from the tongue portion 43 toward the discharge portion 42.

The peripheral wall 4c is a wall provided between the side walls 4a facing each other, and forms a curved surface along the rotation direction of the blower fan 2. The peripheral wall 4c is arranged parallel to the axial direction of the rotation axis RA and covers the blower fan 2. Note that the peripheral wall 4c may have a form that is inclined with respect to the axial direction of the rotation axis RA of the blower fan 2, and is not limited to a form that is arranged parallel to the axial direction of the rotation axis RA.

The peripheral wall 4c constitutes an inner wall surface facing the outer peripheral surface 2f (see FIG. 3) of the blower fan 2. The peripheral wall 4c faces the outer peripheral side ends of the plurality of blades 2d that constitute the outer peripheral surface 2f of the blower fan 2. The peripheral wall 4c faces the air blowing side of the blades 2d of the blower fan 2. As shown in FIG. 1, the peripheral wall 4c extends from a tongue portion 43 that is a spiral-shaped winding start portion to a winding end portion 41b that is located at the boundary between the discharge portion 42 and the scroll portion 41 on the side away from the tongue portion 43. , are provided along the rotation direction of the blower fan 2.

The tongue portion 43 is an upstream end of the peripheral wall 4c that forms a curved surface in the direction in which gas flows through the internal space of the scroll casing 4 along the peripheral wall 4c due to the rotation of the blower fan 2. The winding end portion 41b is the downstream end of the peripheral wall 4c forming a curved surface in the direction in which gas flows through the internal space of the scroll casing 4 along the peripheral wall 4c due to the rotation of the blower fan 2.

(Tongue 43)
The scroll casing 4 forms a curved surface at a winding start portion of the peripheral wall 4c near the rotation axis RA of the blower fan 2, and has a tongue portion 43 that guides the airflow generated by the blower fan 2 to the discharge port 42a. The peripheral wall 4c includes a tongue portion 43 at the end on the discharge portion 42 side. The tongue portion 43 is formed at the beginning of the spiral-shaped peripheral wall 4c.

The tongue portion 43 is provided at the boundary between the discharge portion 42 and the diffuser plate 42c, which will be described later. The tongue portion 43 is formed to have a curved surface, and is formed in an arc shape when viewed from the axial direction of the rotation axis RA. The tongue portion 43 is formed with a predetermined radius of curvature, and the peripheral wall 4c is smoothly connected to the diffuser plate 42c via the tongue portion 43. The tongue portion 43 has substantially the same shape in the axial direction of the rotation axis RA when viewed from the discharge port 42a, and has a shape along the axial direction of the rotation axis RA.

The tongue portion 43 suppresses the inflow of air from the end of the spiral flow path to the beginning of the winding inside the scroll casing 4. The tongue portion 43 is provided at an upstream portion of the ventilation path, and separates the air flow in the rotation direction of the blower fan 2 and the air flow in the discharge direction from the downstream portion of the ventilation path toward the discharge port 42a. have a role. Further, the static pressure of the air flowing into the discharge portion 42 increases while passing through the scroll casing 4, and becomes high pressure. Therefore, the tongue portion 43 has a function of partitioning off such a pressure difference. The tongue portion 43 has a function of partitioning a pressure difference, and also has a function of guiding air flowing into the discharge portion 42 to each flow path due to its curved surface.

(Discharge part 42)
The discharge part 42 forms a discharge port 42a through which the airflow generated by the blower fan 2 and passed through the scroll part 41 is discharged. The discharge portion 42 is constituted by a hollow tube having a rectangular cross section perpendicular to the direction in which air flows along the peripheral wall 4c. Note that the cross-sectional shape of the discharge portion 42 is not limited to a rectangle. The discharge part 42 forms a flow path that guides the air sent out from the blower fan 2 and flowing through the gap between the peripheral wall 4c and the blower fan 2 so as to be discharged to the outside of the scroll casing 4.

One end of the discharge section 42 forms an inlet (not shown) through which air flows into the discharge section 42 from the scroll casing 4. Further, the other end of the discharge section 42 forms a discharge port 42a through which the air that has flowed through the flow path within the discharge section 42 is discharged to the outside air.

As shown in FIG. 2, the discharge part 42 has an extension plate 42b, a diffuser plate 42c, a first side plate part 42d, and a second side plate part 42e. The extension plate 42b is formed integrally with the peripheral wall 4c so as to smoothly continue to the winding end portion 41b on the downstream side of the peripheral wall 4c. The diffuser plate 42c is formed integrally with the tongue portion 43 of the scroll casing 4, and faces the extension plate 42b. For example, the diffuser plate 42c is formed at a predetermined angle with respect to the extension plate 42b so that the cross-sectional area of the flow path gradually expands along the direction in which air flows in the discharge portion 42. It is not limited to this configuration.

The first side plate portion 42d is formed integrally with one side wall 4a of the scroll casing 4, and the second side plate portion 42e is formed integrally with the other side wall 4a of the scroll casing 4. The first side plate portion 42d and the second side plate portion 42e are formed between the extension plate 42b and the diffuser plate 42c. Thus, in the discharge section 42, a flow path having a rectangular cross section is formed by the extension plate 42b, the diffuser plate 42c, the first side plate part 42d, and the second side plate part 42e.

[Operation of multi-blade centrifugal blower 1]
The operation of the multi-blade centrifugal blower 1 will be explained using FIG. 2. In the multi-blade centrifugal blower 1, when a motor (not shown) is driven, a main plate 2a to which a motor shaft is connected rotates, and a plurality of blades 2d rotate around a rotation axis RA via the main plate 2a. When the blower fan 2 rotates, air outside the scroll casing 4 is sucked into the scroll casing 4 through the suction port 5.

The air sucked into the scroll casing 4 is guided by the bell mouth 3 and sucked into the blower fan 2. The air sucked into the blower fan 2 becomes an airflow to which dynamic pressure and static pressure are added during the process of passing between the plurality of blades 2d, and is blown out toward the outside in the radial direction of the blower fan 2. Ru. The airflow blown out from the blower fan 2 is blown out into the scroll casing 4 from the blower fan 2 due to the pressure increasing action of the blower fan 2 .

The airflow flowing inside the scroll casing 4 is pressurized by flowing through an air path that gradually expands from the winding start side to the winding end side by the spiral-shaped peripheral wall 4c. The air blown into the scroll casing 4 from the blower fan 2 is decelerated in the enlarged air path formed by the peripheral wall 4c of the scroll casing 4, recovers static pressure, and is discharged to the outside from the discharge port 42a shown in FIG. It's blown out.

[Operation and effect of blower fan 2 and multi-blade centrifugal blower 1]
In the blower fan 2, each of the plurality of blades 2d protrudes and is fixed to the side opposite to the installation side of the main plate 2a of the side plate 2c, and forms a fixed part between each of the plurality of blades 2d and the side plate 2c. It is formed to have an engaging portion 20. The engaging portion 20 has a curved surface portion 20a that forms a convex curved surface toward the rotation direction R of the plurality of blades 2d. The blower fan 2 has the engaging portion 20 curved in the rotation direction R of the blower fan 2, so that when the blower fan 2 rotates, airflow flows on the opposite side of the side plate 2c from the installation side of the main plate 2a. passes smoothly along the curved surface of the engaging portion 20. In the blower fan 2, the airflow passes smoothly along the curved surface of the engaging portion 20, and interference of the airflow at the fixed portion between the blade 2d and the side plate 2c is suppressed, so noise generated from the blower fan 2 is suppressed. As a result, the aerodynamic characteristics of the blower fan 2 are improved.

Further, in the blower fan 2, the plurality of engaging portions 20 are respectively inserted into the plurality of through holes 22 of the side plate 2c, and the portions protruding from the plurality of through holes 22 are in the rotation direction R of the plurality of blades 2d. It is bent toward the side and fixed to the side plate 2c. In the blower fan 2, since the engaging portion 20 is bent toward the rotation direction R of the fan, the side plate 2c does not come off from the blade 2d when the fan rotates, and the fixation between the side plate 2c and the blade 2d can be strengthened. . That is, the blower fan 2 can suppress generated noise, improve aerodynamic characteristics, and further strengthen the fixation between the side plate 2c and the blade 2d.

Further, the curved surface portion 20a is formed by the tip portions 20b of the plurality of engaging portions 20 in the rotation direction R. The airflow is generated from the blower fan 2 because the airflow passes smoothly along the curved surface of the tip portion of the engaging portion 20, and interference of the airflow at the fixed portion between the blade 2d and the side plate 2c is suppressed. Noise is suppressed and the aerodynamic characteristics of the blower fan 2 are improved.

Furthermore, the multi-blade centrifugal blower 1 is equipped with a blower fan 2. Therefore, the multi-blade centrifugal blower 1 can obtain the same effects as the blower fan 2. That is, in the multi-blade centrifugal blower 1, interference of airflow at the fixed portion between the blades 2d and the side plate 2c is suppressed, so noise generated from the blower fan 2 is suppressed, and the aerodynamic characteristics of the blower fan 2 are improved. In addition, in the multi-blade centrifugal blower 1, since the engaging portion 20 is bent toward the rotation direction R of the fan, the side plate 2c does not come off from the blade 2d when the fan rotates, and the side plate 2c and the blade 2d are fixed. can be strengthened.

Embodiment 2.
FIG. 6 is a perspective view of the blower fan 2 of the multi-blade centrifugal blower 1 according to the second embodiment. FIG. 7 is a plan view of the blower fan 2 of the multi-blade centrifugal blower 1 according to the second embodiment. In addition, in FIG. 7, the wing 2d is shown through the side plate 2c to show the shape of the wing 2d. Components having the same configuration as the multi-blade centrifugal blower 1 shown in FIGS. 1 to 4 are given the same reference numerals, and their explanations will be omitted. In the blower fan 2 of the second embodiment, the configuration of the blades 2d is further specified.

As shown in FIG. 6, the blades 2d of the multi-blade centrifugal blower 1 according to the second embodiment are inclined such that the leading edge 24a moves away from the rotation axis RA as it goes from the main plate 2a side to the side plate 2c side. are doing. The leading edge 24a of the blade 2d is inclined such that the inner diameter of the blade increases from the main plate 2a side toward the side plate 2c side.

As shown in FIGS. 6 and 7, the blades 2d of the multi-blade centrifugal blower 1 according to the second embodiment include a turbo blade portion 26 including an inner peripheral end 24 and configured as a backward blade, and an outer peripheral end 25. It has a sirocco wing section 27 configured as a forward vane. The turbo blade portion 26 is a portion that constitutes a backward blade in a portion on the inner peripheral side of each of the plurality of blades 2d in the radial direction of the blower fan 2. The sirocco blade portion 27 is a portion that constitutes a forward blade on the outer peripheral side of each of the plurality of blades 2d in the radial direction of the blower fan 2.

As shown in FIGS. 6 and 7, the blades 2d of the blower fan 2 of the multi-blade centrifugal blower 1 according to the second embodiment are integrally formed with a turbo blade portion 26 and a sirocco blade portion 27. The blades 2d are integrally formed in the radial direction of the blower fan 2 in the order of the turbo blade portion 26 and the sirocco blade portion 27 from the rotation axis RA toward the outer circumferential side. The blades 2d of the multi-blade centrifugal blower 1 according to the second embodiment have a turbo-in-sirocco blade shape in which the radially inner peripheral side is a turbo blade and the outer peripheral side is a sirocco blade.

[Operation and effect of blower fan 2 and multi-blade centrifugal blower 1]
Each of the plurality of blades 2d includes a turbo blade section 26 configured as a rear blade in a radially inner portion around the rotation axis RA of the main plate 2a, and a forward blade in a radially outer portion. It has a sirocco wing portion 27 configured as a facing blade. Even if the blower fan 2 has a turbo-in sirocco blade shape, it can obtain the same effects as the blower fan 2 according to the first embodiment. Moreover, since the multi-blade centrifugal blower 1 according to the second embodiment includes the blower fan 2 according to the second embodiment, it is possible to obtain the same effect as the blower fan 2 according to the second embodiment. .

Embodiment 3.
FIG. 8 is an enlarged view of the blower fan 2 of the multi-blade centrifugal blower 1 according to the third embodiment. FIG. 8 is a conceptual diagram in which the blades 2d of the blower fan 2 are enlarged. Components having the same configuration as the multi-blade centrifugal blower 1 shown in FIGS. 1 to 6 are designated by the same reference numerals, and the description thereof will be omitted. In the blower fan 2 of the third embodiment, the configuration of the blades 2d is further specified.

In the multi-blade centrifugal blower 1 according to the third embodiment, each of the plurality of blades 2d is formed such that the leading edge 24a of the tip portion 2g is located inside the side plate 2c. The tip portion 2g is an end portion closer to the side plate 2c in the axial direction of the rotation axis RA. The blower fan 2 is formed so that the front edge 24a of the tip portion 2g of the blade 2d protrudes inward from the side plate 2c when viewed in the axial direction of the rotation axis RA. That is, in the blower fan 2, each of the plurality of blades 2d is arranged such that the front edge 24a of the blade 2d protrudes inward from the side plate 2c at a portion of the main plate 2a near the side plate 2c in the axial direction of the rotation axis RA. It is formed.

A line L shown in FIG. 8 is a line parallel to the rotation axis RA, and represents the position of the inner peripheral edge 2c3 of the side plate 2c in the radial direction. As shown in FIG. 8, the blower fan 2 is configured such that the front edge 24a of the tip 2g of the blade 2d is located closer to the rotation axis RA than the line L representing the position of the inner peripheral edge 2c3 of the side plate 2c in the radial direction. is formed.

[Operation and effect of blower fan 2 and multi-blade centrifugal blower 1]
Each of the plurality of blades 2d is formed such that a leading edge 24a of the blade 2d protrudes inward from the side plate 2c in a portion close to the side plate 2c in the axial direction of the rotation axis RA of the main plate 2a. In the blower fan 2 according to the third embodiment, the blade area is increased by making the blades 2d on the side plate 2c side protrude inward from the side plate 2c, compared to a case where the blades do not protrude from the side plate 2c. As the blade area increases, the amount of air discharged increases. Further, the blower fan 2 according to the third embodiment can obtain the same effects as the blower fan 2 according to the first embodiment. Moreover, since the multi-blade centrifugal blower 1 according to the third embodiment includes the blower fan 2 according to the third embodiment, it has the same effect as the blower fan 2 according to the third embodiment and the first embodiment. can be obtained.

Embodiment 4.
[Air conditioner 100]
FIG. 9 is a conceptual diagram showing the configuration of air conditioner 100 according to Embodiment 4. Components having the same configuration as the multi-blade centrifugal blower 1 shown in FIGS. 1 to 8 are denoted by the same reference numerals, and the description thereof will be omitted. The air conditioner 100 according to the fourth embodiment is an example of how the multi-blade centrifugal blower 1 is used.

The air conditioner 100 according to Embodiment 4 performs air conditioning by heating or cooling a room by transferring heat between outside air and indoor air via a refrigerant. Air conditioner 100 according to Embodiment 4 includes an air conditioning outdoor unit 110 and an air conditioning indoor unit 120. In the air conditioner 100, an air conditioner outdoor unit 110 and an air conditioner indoor unit 120 are connected by a refrigerant pipe 106 to form a refrigerant circuit in which refrigerant circulates. In the refrigerant circuit of the air conditioner 100, a compressor 101, a flow path switching device 102, an outdoor heat exchanger 103, an expansion valve 104, and an indoor heat exchanger 105 are sequentially connected via a refrigerant pipe 106. Note that the air conditioner 100 does not need to include the flow path switching device 102.

(Air conditioner outdoor unit 110)
The air conditioning outdoor unit 110 includes a compressor 101, a flow path switching device 102, an outdoor heat exchanger 103, and an expansion valve 104. The compressor 101 compresses and discharges the refrigerant that it sucks in. The flow path switching device 102 is, for example, a four-way valve, and is a device that switches the direction of the refrigerant flow path. The air conditioner 100 can realize heating operation or cooling operation by switching the flow of refrigerant using the flow path switching device 102 based on instructions from a control device (not shown).

The outdoor heat exchanger 103 exchanges heat between the refrigerant and outdoor air. The outdoor heat exchanger 103 functions as an evaporator during heating operation, and exchanges heat between the low-pressure refrigerant flowing from the refrigerant pipe 106 on the expansion valve 104 side and outdoor air to evaporate and vaporize the refrigerant. . During cooling operation, the outdoor heat exchanger 103 functions as a condenser, and exchanges heat between the refrigerant already compressed by the compressor 101 that flows in from the refrigerant pipe 106 on the flow path switching device 102 side and outdoor air. The refrigerant is condensed and liquefied.

The outdoor heat exchanger 103 is provided with an outdoor blower 108 in order to increase the efficiency of heat exchange between the refrigerant and outdoor air. The expansion valve 104 is a throttle device (flow control means), and functions as an expansion valve by adjusting the flow rate of the refrigerant flowing through the expansion valve 104, and adjusts the pressure of the refrigerant by changing the degree of opening. For example, when the expansion valve 104 is configured with an electronic expansion valve or the like, the opening degree of the expansion valve 104 is adjusted based on instructions from a control device (not shown).

(Air conditioning indoor unit 120)
FIG. 10 is a perspective view of an air conditioning indoor unit 120 included in an air conditioner 100 according to the fourth embodiment. In addition, in FIG. 10, in order to show the internal configuration of the air conditioning indoor unit 120, illustration of a part of the wall that covers the multi-blade centrifugal blower 1 is omitted. A white arrow A1 shown in FIG. 10 indicates the inflow direction of the airflow flowing into the housing 121, and a white arrow A2 indicates the outflow direction of the airflow flowing out from the housing 121.

As shown in FIGS. 9 and 10, the air conditioning indoor unit 120 includes a multi-blade centrifugal blower 1 and an indoor heat exchanger 105 through which air flowing by the multi-blade centrifugal blower 1 passes. The air conditioning indoor unit 120 also includes a motor 107 that rotates the blower fan 2 of the multi-blade centrifugal blower 1, as shown in FIG. Moreover, the air conditioning indoor unit 120 according to the fourth embodiment includes a housing 121 installed in the air-conditioned space.

The indoor heat exchanger 105 adjusts the temperature and humidity of air that is sucked into the housing 121 and blown out from the housing 121 into the air-conditioned space. During heating operation, the indoor heat exchanger 105 functions as a condenser and exchanges heat between the refrigerant already compressed by the compressor 101 that flows into the refrigerant pipe 106 on the flow path switching device 102 side and indoor air. , condenses and liquefies the refrigerant. The indoor heat exchanger 105 functions as an evaporator during cooling operation, and exchanges heat between the refrigerant brought into a low pressure state by the expansion valve 104 and indoor air, causing the refrigerant to absorb heat from the air and evaporate. and vaporize it.

The multi-blade centrifugal blower 1 adjusts the flow of air when the indoor heat exchanger 105 performs heat exchange. Multi-blade centrifugal blower 1 is connected to motor 107 via motor shaft 107a. In the air conditioning indoor unit 120, an inverter device may be attached to the motor 107, and the rotational speed of the blower fan 2 may be changed by changing the operating frequency of the motor 107.

The housing 121 is formed into a rectangular parallelepiped shape. Note that the shape of the casing 121 is not limited to a rectangular parallelepiped shape, and may have other shapes such as a cylindrical shape, a prismatic shape, a conical shape, a shape with a plurality of corners, a shape with a plurality of curved surfaces, etc. It may be.

The housing 121 has a suction wall portion 121a in which a case suction port 122 is formed. The case suction port 122 is a through hole formed in the casing 121, and is a portion through which air sucked into the casing 121 from the outside through the driving of the multi-blade centrifugal blower 1 is driven. A filter for removing dust from the air may be placed in the case intake port 122. The housing 121 has a discharge wall portion 121b in which a case discharge port 123 is formed. The case discharge port 123 is a through hole formed in the casing 121, and is a portion through which air discharged from the inside of the casing 121 to the outside is passed when the multi-blade centrifugal blower 1 is driven.

The multi-blade centrifugal blower 1 and the indoor heat exchanger 105 are housed inside the casing 121. Further, a motor 107 is housed inside the housing 121. The motor 107 has a motor shaft 107a connected to the blower fan 2. The multi-blade centrifugal blower 1 forms a flow of air that is sucked into the housing 121 from a case inlet 122 and blown out from a case outlet 123 into a space to be air-conditioned. The indoor heat exchanger 105 is disposed within the housing 121 on the wind path of the air discharged by the multi-blade centrifugal blower 1 .

When the blower fan 2 of the multi-blade centrifugal blower 1 rotates due to the rotation of the motor 107, air in the air-conditioned space is sucked into the casing 121 through the case suction port 122. The air sucked into the interior of the housing 121 is sucked into the blower fan 2, and the air sucked into the blower fan 2 is blown out toward the outside in the radial direction of the blower fan 2. The air blown from the blower fan 2 passes through the inside of the scroll casing 4 (see FIG. 1), is blown out from the discharge port 42a of the scroll casing 4, and is supplied to the indoor heat exchanger 105. When the air supplied to the indoor heat exchanger 105 passes through the indoor heat exchanger 105, it exchanges heat with the refrigerant flowing inside the indoor heat exchanger 105, and its temperature and humidity are adjusted. The air that has passed through the indoor heat exchanger 105 is blown out from the case outlet 123 into the air-conditioned space.

[Example of operation of air conditioner 100]
Next, a cooling operation will be described as an example of the operation of the air conditioner 100. The high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 101 flows into the outdoor heat exchanger 103 via the flow path switching device 102 . The gas refrigerant that has flowed into the outdoor heat exchanger 103 is condensed through heat exchange with the outside air blown by the outdoor blower 108, becomes a low-temperature refrigerant, and flows out of the outdoor heat exchanger 103.

The refrigerant flowing out from the outdoor heat exchanger 103 is expanded and depressurized by the expansion valve 104, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the indoor heat exchanger 105 of the air conditioning indoor unit 120, evaporates through heat exchange with the indoor air blown by the multi-blade centrifugal blower 1, and becomes a low-temperature, low-pressure gas refrigerant indoors. It flows out from the heat exchanger 105. At this time, the indoor air that has been cooled by heat absorption by the refrigerant becomes conditioned air and is blown out from the case outlet 123 of the air conditioner indoor unit 120 into the air-conditioned space. The gas refrigerant flowing out of the indoor heat exchanger 105 is sucked into the compressor 101 via the flow path switching device 102 and is compressed again. The air conditioner 100 repeats the above operations during cooling operation.

Next, a heating operation will be described as an example of the operation of the air conditioner 100. The high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 101 flows into the indoor heat exchanger 105 of the air conditioning indoor unit 120 via the flow path switching device 102 . The gas refrigerant that has flowed into the indoor heat exchanger 105 is condensed through heat exchange with the indoor air blown by the multi-blade centrifugal blower 1, becomes a low-temperature refrigerant, and flows out from the indoor heat exchanger 105. At this time, the indoor air that has received heat from the gas refrigerant and is warmed becomes conditioned air and is blown out from the case discharge port 123 of the air conditioner indoor unit 120 into the air-conditioned space.

The refrigerant flowing out of the indoor heat exchanger 105 is expanded and depressurized by the expansion valve 104, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the outdoor heat exchanger 103 of the air conditioner outdoor unit 110, evaporates through heat exchange with the outside air blown by the outdoor blower 108, and becomes a low-temperature, low-pressure gas refrigerant that is transferred to the outdoor heat exchanger 103. It flows out from 103. The gas refrigerant flowing out from the outdoor heat exchanger 103 is sucked into the compressor 101 via the flow path switching device 102 and is compressed again. The air conditioner 100 repeats the above operations during heating operation.

[Operations and effects of the air conditioner 100 and the air conditioning indoor unit 120]
Since the air conditioner 100 according to the fourth embodiment includes the multi-blade centrifugal blower 1 according to the first to third embodiments, it is similar to the multi-blade centrifugal blower 1 according to the first to third embodiments. effect can be obtained. Furthermore, since the air conditioning indoor unit 120 includes the multi-blade centrifugal blower 1 according to the first to third embodiments, it obtains the same effects as the multi-blade centrifugal blower 1 according to the first to third embodiments. be able to.

Although the preferred embodiments have been described in detail above, they are not limited to the embodiments described above, and various modifications may be made to the embodiments described above without departing from the scope of the claims. Variations and substitutions can be made. Although the multi-blade centrifugal blower 1 is used for air conditioning, the multi-blade centrifugal blower 1 is not limited to being used for air conditioning. The multi-blade centrifugal blower 1 can be used, for example, in devices that utilize a refrigeration cycle, such as refrigerators, freezers, vending machines, refrigeration equipment, and water heaters.

1 Multi-blade centrifugal blower, 2 Blower fan, 2a main plate, 2a1 periphery, 2b boss, 2b1 shaft hole, 2c side plate, 2c1 first side plate, 2c2 second side plate, 2c3 inner periphery, 2d blade, 2d1 positive pressure surface, 2d2 negative pressure surface, 2e fan suction port, 2f outer peripheral surface, 2g tip end, 2h base end, 3 bell mouth, 4 scroll casing, 4a side wall, 4a1 first side wall, 4a2 second side wall, 4c peripheral wall, 5 suction port, 12a first wing section, 12b second wing section, 20 engaging section, 20a curved surface section, 20b tip section, 21 main body section, 22 through hole, 24 inner peripheral end, 24a leading edge, 25 outer peripheral end, 25a trailing edge, 26 Turbo wing section, 27 Scirocco wing section, 41 Scroll section, 41b winding end section, 42 Discharge section, 42a Discharge port, 42b Extension plate, 42c Diffuser plate, 42d First side plate section, 42e Second side plate section, 43 Tongue Part, 100 Air conditioner, 101 Compressor, 102 Flow path switching device, 103 Outdoor heat exchanger, 104 Expansion valve, 105 Indoor heat exchanger, 106 Refrigerant piping, 107 Motor, 107a Motor shaft, 108 Outdoor blower, 110 Air conditioning Outdoor unit, 120 air conditioning indoor unit, 121 housing, 121a suction wall, 121b discharge wall, 122 case inlet, 123 case outlet.

Claims

A disc-shaped main plate,
a plurality of wings installed on the peripheral edge of the main plate;
an annular side plate that faces the main plate and fixes an end of the plurality of wings on the opposite side to the main plate;
Equipped with
Each of the plurality of wings is
an engaging portion that protrudes and is fixed to a side opposite to the installation side of the main plate of the side plate, and that forms a fixed portion between each of the plurality of wings and the side plate;
The engaging portion is
A blower fan having a curved surface portion forming a convex curved surface toward the rotation direction of the plurality of blades.
The engaging portion is
provided at the tip of each of the plurality of blades in the axial direction of the rotation axis of the main plate,
The side plate includes
A plurality of through holes are formed for fixing the plurality of wings, respectively,
The engaging portion is
are respectively inserted into the plurality of through holes of the side plate,
The blower fan according to claim 1, wherein a portion protruding from the plurality of through holes is bent toward the rotation direction of the plurality of blades and fixed to the side plate.
The engaging portion is formed in a plate shape,
The curved surface portion is
The fan for an air blower according to claim 1 or 2, wherein the fan is formed by a tip end portion of the engaging portion in the rotational direction.
Each of the plurality of wings is
a turbo blade section configured as a rearward blade in an inner peripheral side portion in a radial direction centering on the rotation axis of the main plate; and a sirocco blade section configured as a forward blade in an outer peripheral side portion in the radial direction. The blower fan according to any one of claims 1 to 3, comprising:
Each of the plurality of wings is
The blower fan according to any one of claims 1 to 4, wherein a front edge of a blade is formed to protrude inward from the side plate in a portion close to the side plate in the axial direction of the rotation axis of the main plate. .
The blower fan according to any one of claims 1 to 5,
a peripheral wall formed in a spiral shape, and at least one side wall having a bell mouth forming an inlet, forming an outlet from which airflow generated by the blower fan is discharged; A scroll casing that houses the fan,
Multi-blade centrifugal blower with.
The multi-blade centrifugal blower according to claim 6;
a heat exchanger through which air flowing by the multi-blade centrifugal blower passes;
Air conditioning indoor unit equipped with.