TW202129157A - Centrifugal blower and air conditioning device - Google Patents

Abstract

A centrifugal blower is provided with: an impeller including a rotationally driven main plate, an annular side plate, and a plurality of blades arranged on the circumferential edge of the main plate with one end thereof connected with the main plate and the other end connected with the side plate; and a scroll casing for accommodating the impeller, said scroll casing including a circumferential wall formed in a spiral shape and a side wall having a bell mouth which forms a suction port. The bell mouth includes a bell mouth circumferential wall formed protruding from the side wall in a cylindrical shape and an air intake section that is formed in an annular shape, in which the outer circumferential edge is connected with the end of the bell mouth circumferential wall in the direction of protrusion thereof, and in which the inner circumferential edge forms the suction port and has an opening diameter which gradually decreases toward the interior of the scroll casing. The scroll casing includes a barrier section provided between the bell mouth circumferential wall and the inner circumferential edge and extending from the side wall toward the impeller side. The scroll casing is formed so that the distance between the barrier section and the side wall is smaller than the distance between the circumferential wall and the side plate and the distance between the bell mouth circumferential wall and the side plate.

Description

Centrifugal fan and air conditioner

The present invention relates to a centrifugal fan with a scroll casing and an air conditioner including the centrifugal fan.

Conventionally, a centrifugal fan system has a scroll shell, which is in the shape of a scroll, and gradually expands the air path to guide it to the outlet; and an impeller, which is housed in the scroll shell and rotates around the axis. Moreover, there is a bell mouth that guides the airflow to the impeller in the air suction port of the scroll shell. In addition, the impeller system has: a plurality of blades; a main plate in which the plurality of blades are arranged on the circumference of the rotating shaft; and a side plate having a ring shape to connect the ends of each suction side of the plurality of blades to each other.

In this kind of centrifugal fan, the airflow flowing out between adjacent blades by the rotation of the impeller has a velocity distribution in the axial direction of the rotating shaft of the impeller. The velocity distribution of the airflow is offset to the side plate side due to the environment in which it is used. Sometimes a part of the airflow is counter-current and does not flow into the scroll shell, but flows along the inner side of the bell mouth. As a result, the airflow flowing in the scroll shell leaks, and the airflow flowing along the bell mouth flows into the interior of the impeller to collide with the fan blades, producing a loud noise of the wind cutting sound of the fan blades.

Here, in order to prevent the air flow out of the impeller from flowing into the impeller again, a centrifugal fan with a backflow prevention plate protruding from the inner wall of the scroll shell to the extending direction of the rotating shaft is proposed (for example, refer to the patent document). 1). The centrifugal fan of Patent Document 1 aims to prevent air leakage to the suction side of the impeller by changing the length of the backflow prevention plate on the impeller in the circumferential direction, and to prevent deterioration of fan performance. [Patent Literature]

[Patent Document 1] JP 2014-77380 A

However, in the centrifugal fan of Patent Document 1, a backflow prevention plate extending in the axial direction of the rotating shaft of the impeller is provided, whereby the countercurrent airflow is bent in the axial direction of the rotation shaft by the backflow prevention plate. Therefore, the backflow airflow that is bent toward the axial direction of the rotating shaft and flows along the backflow prevention plate may interfere with the airflow flowing out of the impeller, which may cause noise.

The present invention was developed to solve the above-mentioned problems, and its purpose is to obtain a centrifugal fan and air-conditioning device that prevent the airflow flowing out of the impeller from flowing into the impeller while suppressing the noise generated by the airflow.

The centrifugal fan of the present invention includes: an impeller having: a main plate, which is driven by rotation; a side plate, which is ring-shaped and is arranged opposite to the main plate; The peripheral part of the main plate; and the scroll shell, which accommodates the impeller, has: a peripheral wall formed in a scroll shape; and a side wall having a bell mouth that forms a suction port communicating with the space formed by the main plate and the plurality of blades; a horn; The mouth system has: the peripheral wall of the bell mouth that protrudes from the side wall and is formed into a cylindrical shape; and the air intake part is formed in a ring shape to form the outer peripheral edge portion of the outer peripheral side, which is the end of the protruding direction of the peripheral wall of the bell mouth The inner peripheral edge of the edge forming the inner peripheral side forms a suction port, and the diameter of the opening gradually decreases toward the inside of the scroll shell; the scroll shell is located in the radial direction of the impeller and has a peripheral wall provided in the bell mouth Between the inner periphery and the inner periphery, the shielding wall extending from the side wall to the impeller side. The shielding wall is the distance between the shielding wall and the side plate, and is formed to be smaller than the distance between the peripheral wall and the side plate and the distance between the bell mouth peripheral wall and the side plate .

The air conditioner of the present invention includes the above-mentioned centrifugal fan and a heat exchanger arranged at a position facing the outlet of the centrifugal fan. [Invention Effect]

According to the present invention, the scroll casing of the centrifugal fan is located in the radial direction of the impeller, and has a shielding wall portion arranged between the peripheral wall of the bell mouth and the inner peripheral edge portion and extending from the side wall to the impeller side. Moreover, the distance between the shielding wall portion and the side plate is formed to be smaller than the distance between the peripheral wall and the side plate and the distance between the bell mouth peripheral wall and the side plate. Therefore, the air flow out of the impeller is prevented from flowing in the direction of the impeller through the shielding wall portion, and flows along the shielding wall portion extending in the radial direction of the impeller. As a result, the present invention can prevent the airflow flowing out of the impeller from flowing into the impeller, and at the same time suppress the noise generated by the airflow.

Hereinafter, the centrifugal fan 1 and the air conditioner 60 of the embodiment will be described with reference to the drawings and the like. Moreover, in the following drawings including FIG. 1, the relative size relationship and shape of each constituent member may be different from the actual ones. In addition, in the following drawings, those assigned the same number are the same or equivalent, and they are regarded as common throughout the entire patent specification. Also, for ease of understanding, although it is appropriate to use terms that indicate direction (such as "up", "down", "right", "left", "front" and "rear", etc.), these expressions are only for convenience of explanation However, this description is not used to limit the arrangement and direction of the device or parts.

Implementation mode 1. [Centrifugal fan 1] Fig. 1 is a perspective view schematically showing the centrifugal fan 1 of the first embodiment. FIG. 2 is an outline view of the structure of the centrifugal fan 1 of the first embodiment viewed in parallel with the rotation axis RS. Fig. 3 is a cross-sectional view schematically showing the A-A line cross section of the centrifugal fan 1 shown in Fig. 2. 1 to 3, the basic structure of the centrifugal fan 1 will be explained. The centrifugal fan 1 is, for example, a multi-blade fan or a multi-blade centrifugal fan such as a turbo fan. The centrifugal fan 1 is a single suction fan in which air is sucked in from one side of the scroll shell 4 in the axial direction of the virtual rotating shaft RS of the impeller 2.

(Impeller 2) The impeller 2 is a centrifugal fan. The impeller 2 is rotationally driven by the driving device 6, and the centrifugal force generated by the rotation forces the air to be sent out in the radial direction. The impeller 2 is driven by the driving device 6 to rotate in the direction of rotation R indicated by the arrow. The driving device 6 is, for example, a motor, and applies driving force to the impeller 2. As shown in FIG. 3, the driving device 6 is arranged in the scroll shell 4. However, the driving device 6 may be arranged outside the scroll shell 4, and is connected to the impeller 2 by a rotating shaft (illustration omitted). The main board 2a is connected.

The impeller 2 has: a main plate 2a, which is rotatably driven by the driving device 6, a side plate 2c, which has a ring shape and is arranged opposite to the main plate 2a; and a plurality of fan blades 2d, one end is connected to the main plate 2a, and the other end is connected to the side plate 2c , Are arranged on the peripheral edge portion 2a1 of the main plate 2a.

The main plate 2a is connected to the central portion 2a2 of the driving device 6, and is configured to be relative to the peripheral portion 2a1 connected to the plurality of blades 2d, in the axial direction of the rotating shaft RS, toward the side plate 2c side, that is, toward The cross-sectional shape of the mountain-shaped bulge on the side of the suction port 2e. In addition, the driving device 6 is arranged in a recess formed by the inner surface of the bulging portion of the main plate 2a. Moreover, the shape of the main plate 2a is not limited to those having a mountain-shaped cross-sectional shape. The main plate 2a may be, for example, a disc-shaped member formed in a plate shape. In the central portion 2a2 of the main board 2a, a shaft portion 2b to which the drive device 6 is connected is provided. The main board 2a is rotated and driven by the driving device 6 through the shaft portion 2b.

In addition, the impeller 2 has an annular side plate 2c that is attached to the end on the opposite side of the main plate 2a of the plurality of blades 2d in the axial direction of the rotating shaft RS. The side plate 2c maintains the positional relationship of the tips of the respective blades 2d by connecting the plural blades 2d, and further strengthens the plural blades 2d.

Each of the plurality of blades 2d is connected to the main board 2a at one end, and connected to the side board 2c at the other end, and is arranged in the circumferential direction with the virtual rotation axis RS of the main board 2a as the center. The plural blades 2d are arranged between the main plate 2a and the side plate 2c. Each fan blade 2d is attached to the peripheral edge part 2a1 of the main plate 2a, and is arrange|positioned at a fixed interval from each other.

As shown in Figs. 1 and 3, the impeller 2 is configured in a cylindrical shape by a plurality of blades 2d arranged on the main plate 2a. Furthermore, the impeller 2 is in the axial direction of the rotating shaft RS, and on the side plate 2c side opposite to the main plate 2a, a suction port 2e for inflowing gas into the space 47 enclosed by the main plate 2a and the plurality of blades 2d is formed.

The impeller 2 is driven by the driving device 6 and is driven to rotate around the rotating shaft RS. With the rotation of the impeller 2, the air outside the centrifugal fan 1 passes through the suction port 5 formed in the scroll casing 4 and the suction port 2e of the impeller 2, and is sucked into the space 47 enclosed by the main plate 2a and the plural fan blades 2d. . Moreover, the air sucked into the space 47 enclosed by the main plate 2a and the plurality of blades 2d by the rotation of the impeller 2 passes through the space between the adjacent blades 2d and is sent out to the radially outer side of the impeller 2.

(Scroll Shell 4) As shown in Figs. 1 to 3, the scroll shell 4 accommodates the impeller 2 inside, and rectifies the air blown from the impeller 2. The scroll shell 4 is formed of foamed materials such as expanded styrene. In addition, the scroll shell 4 is not limited to the one formed of foamed material. For example, the scroll shell 4 may be formed of a resin material or a metal material. The scroll shell 4 has a scroll part 41 and a discharge part 42.

(Scroll 41) The scroll portion 41 forms an air path that converts the dynamic pressure of the air flow generated by the impeller 2 to static pressure. The scroll portion 41 has a side wall 4a that covers the impeller 2 in the axial direction of the rotating shaft RS to form a suction port 5 for taking in air; and a peripheral wall 4c that surrounds the impeller 2 in the radial direction of the rotating shaft RS. In addition, the scroll portion 41 has a tongue portion 43 that causes the airflow generated by the impeller 2 to pass through the scroll portion 41 and is guided to the discharge port 42a. Moreover, the radial direction of the rotating shaft RS refers to a direction perpendicular to the axial direction of the rotating shaft RS. The internal space 45 of the scroll portion 41 formed by the peripheral wall 4c and the side wall 4a is a space in which the air blown from the impeller 2 flows along the peripheral wall 4c.

(Side wall 4a) As shown in FIGS. 1 and 3, the side walls 4 a are tied to the axial direction of the rotating shaft RS of the impeller 2 and are arranged on both sides of the impeller 2. As shown in FIG. 3, the side wall 4a of the scroll shell 4 has a first side wall 4a1 and a second side wall 4a2.

The first side wall 4a1 is formed along the first end 4c11 of one side of the peripheral wall 4c in the axial direction of the rotating shaft RS. As shown in FIGS. 1 and 3, the first side wall 4a1 is formed on the side plate 2c side of the impeller 2 between the main plate 2a side and the side plate 2c side in the axial direction of the rotating shaft RS of the impeller 2. A suction port 5 for taking in air is formed in the first side wall 4a1 so that the air can circulate between the impeller 2 and the outside of the scroll shell 4. The suction port 5 system is formed in a circular shape, and the impeller 2 system is arranged such that the center of the suction port 5 and the center system of the shaft portion 2b of the impeller 2 approximately coincide. Moreover, the shape of the suction port 5 is not limited to a circular shape, and it may be another shape such as an ellipse.

The second side wall 4a2 is formed along the second end 4c12 of the other side of the peripheral wall 4c in the axial direction of the rotating shaft RS. As shown in FIGS. 1 and 3, the second side wall 4a2 is formed on the main plate 2a side of the impeller 2 between the main plate 2a side and the side plate 2c side in the axial direction of the rotating shaft RS of the impeller 2. The second side wall 4a2 is formed so as to cover the impeller 2 in the axial direction of the rotating shaft RS. The second side wall 4a2 is formed in a plate shape, and the air suction port 5 is not formed in the second side wall 4a2. The scroll casing 4 of the centrifugal fan 1 is located in the axial direction of the rotating shaft RS of the impeller 2 on one side of the main plate 2a, and has a single suction type casing with a side wall 4a of the suction port 5 formed thereon.

The first side wall 4a1 has a bell mouth 3 forming a suction port 5 communicating with a space 47 formed by the main plate 2a and the plurality of blades 2d. The suction port 5 provided in the first side wall 4a1 is formed by the bell mouth 3 as shown in FIGS. 1 and 3. The bell mouth 3 rectifies the gas sucked by the impeller 2 to flow into the suction port 2e of the impeller 2.

As shown in Fig. 3, the bell mouth 3 is formed so that the diameter of the opening gradually decreases from the outside of the scroll shell 4 to the inside. With this structure of the first side wall 4a1, the air in the vicinity of the suction port 5 flows smoothly along the bell mouth 3, and efficiently flows into the impeller 2 from the suction port 5.

The bell mouth 3 is in the radial direction of the impeller 2 and needs a predetermined length. The bell mouth 3 is when there is no predetermined length in the radial direction of the impeller 2, the curvature of the bell mouth 3 becomes larger, and the air flow flowing along the bell mouth 3 may peel off. The bell mouth 3 is located in the radial direction of the impeller 2 and requires a predetermined length. Therefore, the scroll shell 4 forms a space 46 inside the bell mouth 3. This space 46 may become a space through which the air flow flowing out of the impeller 2 flows into the impeller 2 again.

The bell mouth 3 has: a bell mouth peripheral wall 31 that protrudes from the first side wall 4a1 and is formed into a cylindrical shape; and an air intake portion 32 is formed in a ring shape, and the diameter of the opening is gradually reduced toward the inside of the scroll shell 4 . The air intake portion 32 formed in a ring shape is formed to form an outer peripheral edge portion 32a on the outer peripheral side, and is continuous with the end of the bell mouth peripheral wall 31 in the protruding direction, and forms an inner peripheral edge portion 32b of the inner peripheral side edge. The suction port 5 is formed.

(Zhoubi 4c) The peripheral wall 4c is a wall body provided between the side walls 4a facing each other, and forms a curved surface in the rotation direction R of the impeller 2. The peripheral wall 4c guides the airflow generated by the impeller 2 along the curved wall surface through the scroll portion 41 to the discharge port 42a. The peripheral wall 4c is arranged, for example, to be parallel to the axial direction of the rotating shaft RS of the impeller 2 so as to cover the impeller 2. Furthermore, the peripheral wall 4c may be inclined with respect to the axial direction of the rotating shaft RS of the impeller 2, and it is not limited to the configuration arranged in parallel with the axial direction of the rotating shaft RS. The peripheral wall 4c covers the impeller 2 from the radial direction with respect to the rotating shaft RS, and constitutes an inner peripheral surface facing the plurality of blades 2d. The peripheral wall 4c is opposed to the air blowing side of the blade 2d of the impeller 2.

As shown in Figure 2, the peripheral wall 4c is provided from the scroll start portion 41s located at the boundary with the tongue 43, along the rotation direction R of the impeller 2, to the ejection portion 42 and The scroll end portion 41b at the boundary of the scroll portion 41. The scroll start portion 41s is at the end of the peripheral wall 4c constituting the curved surface on the upstream side of the airflow generated by the rotation of the impeller 2, and the scroll end portion 41b is located on the downstream side of the airflow generated by the rotation of the impeller 2. Ends.

The peripheral wall 4c is tied in the rotation direction R, and is formed in a scroll shape. The scroll shape includes, for example, a logarithmic spiral, an Archimedes spiral, or a scroll shape based on an involute curve. The inner peripheral surface of the peripheral wall 4c constitutes the scroll starting portion 41s from the beginning of the scroll in the shape of a scroll to the end portion 41b of the scroll ending in the scroll of the scroll, and is smooth along the circumferential direction of the impeller 2 The curved surface of the ground. With this structure, the air sent from the impeller 2 flows smoothly through the internal space 45 between the impeller 2 and the peripheral wall 4c in the direction of the discharge portion 42. Therefore, in the scroll shell 4, the static pressure of the air rises efficiently from the tongue portion 43 to the discharge portion 42.

(Discharge part 42) The discharge portion 42 forms a discharge port 42 a generated by the impeller 2 to discharge the air flow passing through the scroll portion 41. The discharge part 42 is comprised by the cross section orthogonal to the flow direction of the air flowing along the peripheral wall 4c, and becomes a rectangular hollow tube. Moreover, the cross-sectional shape of the discharge part 42 is not limited to a rectangle. The discharge part 42 forms a flow path that is guided and sent from the impeller 2 to discharge the air flowing in the internal space 45 between the peripheral wall 4 c and the impeller 2 to the outside of the scroll shell 4.

As shown in FIG. 1, the discharge part 42 has the extension plate 42b, the diffuser 42c, the 1st side wall 4a1, and the 2nd side wall 4a2. The extension plate 42b is formed to extend from the scroll end portion 41b of the peripheral wall 4c, and is a plate-shaped portion integrally formed with the peripheral wall 4c. The diffuser plate 42c is formed integrally with the tongue 43 of the scroll shell 4, and it is a plate-shaped portion arranged opposite to the extension plate 42b. The diffusion plate 42c is formed to have a predetermined angle with the extension plate 42b, so that the cross-sectional area of the flow path gradually expands along the flow direction of the air in the discharge portion 42.

The extension plate 42b and the diffuser plate 42c are formed between the first side wall 4a1 and the second side wall 4a2. In this way, the discharge portion 42 is formed as a flow path with a rectangular cross section by the extension plate 42b, the diffuser plate 42c, the first side wall 4a1, and the second side wall 4a2.

(Tongue 43) In the scroll shell 4, a tongue 43 is formed between the diffuser 42c of the discharge portion 42 and the scroll start portion 41s of the peripheral wall 4c. The tongue 43 is formed with a predetermined radius of curvature, and the peripheral wall 4c penetrates the tongue 43 and is smoothly connected to the diffuser 42c.

The tongue 43 suppresses the inflow of air from the end point of the scroll formed in the scroll-shaped flow path of the scroll shell 4 to the start point of the scroll. The tongue 43 is provided in the upstream part of the ventilation path, and has the role of the split air flowing in the rotation direction R of the impeller 2 and the discharge direction of the outlet 42a from the downstream part of the ventilation path. In addition, when the airflow flowing into the discharge portion 42 passes through the scroll shell 4, the static pressure rises, and the pressure becomes higher than that in the scroll shell 4. Therefore, the tongue 43 has the function of separating this pressure difference.

(Wall part 20) FIG. 4 is an enlarged view of the range AR of the centrifugal fan 1 shown in FIG. 3. 2 to 4, the shielding wall portion 20 will be described. 2 is to illustrate the structure of the shielding wall portion 20, the bell mouth 3 is seen through to schematically show the shielding wall portion 20 arranged inside the bell mouth 3.

As shown in Figures 3 and 4, the scroll shell 4 is located in the radial direction of the impeller 2 and has a shielding wall portion provided between the bell mouth peripheral wall 31 and the inner peripheral edge portion 32b and extending from the side wall 4a to the impeller 2 side 20. The shielding wall 20 prevents the air flow flowing out of the impeller 2 and flowing in the direction of the impeller 2 again. That is, the shielding wall portion 20 obstructs the air flow flowing out of the impeller 2 and passing through the space 46.

The shielding wall portion 20 is located between the bell mouth peripheral wall 31 and the inner peripheral edge portion 32b in a plan view viewed parallel to the axial direction of the rotating shaft RS. That is, the shielding wall portion 20 is not located at a position closer to the axis of the rotation axis RS than the inner peripheral edge portion 32b in a plan view viewed parallel to the axial direction of the rotation axis RS.

As shown in FIG. 2, the shielding wall portion 20 is formed in an annular shape in a plan view viewed in a direction parallel to the axial direction of the rotating shaft RS. In addition, the shielding wall portion 20 is viewed in a plan view in a direction parallel to the axial direction of the rotating shaft RS, and is not limited to being formed in an annular shape, and it may be formed in an arc shape.

Here, in the radial direction of the impeller 2, the distance between the bell mouth peripheral wall 31 and the tip portion 20a forming the inner peripheral edge of the shielding wall portion 20 is defined as the distance DR. The distance DR is in the circumferential direction with the rotation axis RS as the center, and the length can be constant, and the length can also be changed. That is, in the circumferential direction with the rotation axis RS as the center, the length of the distance from DR because of the measurement location can always be the same length, or the length of the distance from DR because of the measurement location can be formed For different lengths. Moreover, the same length includes exactly the same length and approximately the same length.

As shown in FIGS. 3 and 4, the shielding wall portion 20 is formed in a plate shape in a cross section along the rotation axis RS. In addition, the shielding wall portion 20 is not limited to the structure formed in a plate shape. For example, the shielding wall portion 20 may be formed in a block shape having a thickness in the axial direction of the rotation axis RS in a cross section along the rotation axis RS.

As shown in FIGS. 3 and 4, the shielding wall portion 20 is formed in a plate shape, and is formed to extend in a direction perpendicular to the rotation axis RS. Moreover, the extending direction of the shielding portion 20 is not limited to a direction perpendicular to the rotation axis RS, and it may be a direction inclined with respect to a direction perpendicular to the rotation axis RS. That is, the shielding wall portion 20 may be formed in an inclined shape with respect to a direction perpendicular to the rotation axis RS in a cross section along the rotation axis RS. However, the shielding wall portion 20 is not included in the side opposite to the side where the bell mouth 3 is formed with respect to the first side wall 4a1, and is formed in a shape extending in a direction parallel to the rotation axis RS.

As shown in Figures 3 and 4, the shielding wall portion 20 is located in the axial direction of the rotation axis RS of the main plate 2a, and is provided closer to the main plate side end 2c1 than the end of the main plate 2a side of the side plate 2c. The outer peripheral edge portion 32a side. That is, the shielding wall portion 20 is formed between the position of the main plate side end portion 2c1 and the position of the outer peripheral edge portion 32a in a direction parallel to the axial direction of the rotation axis RS of the main plate 2a.

The shielding wall portion 20 is located in the radial direction of the impeller 2 and faces the side plate 2c. For example, as shown in FIGS. 3 and 4, the shielding wall portion 20 is formed in a plate shape, and it is formed to form the tip portion 20a and the side plate 2c of the inner peripheral edge of the shielding wall portion 20, which are tied to the impeller 2 Opposite in the radial direction.

Here, in the radial direction of the impeller 2, the distance between the shielding wall portion 20 and the side plate 2c is taken as the distance D1. In more detail, in the radial direction of the impeller 2, the distance between the tip portion 20a of the shielding wall portion 20 and the side plate 2c is taken as the distance D1. The distance D1 is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c. Furthermore, the distance D1 is formed to be smaller than the distance between the bell mouth peripheral wall 31 and the side plate 2c.

In the first embodiment, the scroll casing 4 has a shielding wall portion 20 extending from the bell mouth peripheral wall 31 to the side plate 2c in a cross section along the rotation axis RS. Regardless of the positional relationship between the end portion of the bell mouth peripheral wall 31 on the first side wall 4a1 side and the side plate 2c of the impeller 2, the distance D1 between the tip portion 20a and the side plate 2c is configured to be smaller than the distance between the peripheral wall 4c and the side plate 2c. The distance and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

FIG. 5 is an enlarged view showing an example of the tip portion 20a of the shielding wall portion 20. As shown in FIG. The tip portion 20a has an inclined portion 20a1 in which the wall surface on the side of the main plate 2a forms an inclined surface, and the thickness becomes thinner as the tip is formed. Moreover, the tip portion 20a is not limited to having the inclined portion 20a1, and it may not have the inclined portion 20a1.

FIG. 6 is an enlarged schematic diagram showing the first example of the shielding wall portion 20. As shown in FIG. As shown in FIG. 6, when the shielding wall portion 20 is formed integrally with the first side wall 4a1, the shielding wall portion 20 protrudes from the first side wall 4a1. As shown in FIG. 6, the shielding wall part 20 may have a drop part 20b. The drop portion 20b protrudes from the first side wall 4a1 to be formed in a cylindrical shape. The drop portion 20b is located in the radial direction of the impeller 2 and faces the bell mouth peripheral wall 31. The shielding wall portion 20 has a drop portion 20b, whereby in the axial direction of the rotating shaft RS, the formation position of the tip portion 20a is different from the formation position of the first side wall 4a1. That is, the wall surface of the shielding portion 20 of the wall constituting the flow path of the airflow and the wall surface of the first side wall 4a1 of the wall constituting the flow path of the airflow are formed with a gap.

The drop portion 20b of the shielding wall portion 20 is in contact with the bell mouth peripheral wall 31, and the shielding wall portion 20 is set in the radial direction of the impeller 2 and extends from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. That is, the outer peripheral edge portion side of the shielding wall portion 20 is formed integrally with the first side wall 4a1, and the shielding wall portion 20 is formed in the radial direction of the impeller 2 and extends from the bell mouth peripheral wall 31 side to the inner peripheral edge portion 32b side. In addition, the drop portion 20b of the shielding wall portion 20 may only be opposed to the bell mouth peripheral wall 31, and it does not need to be in contact with the bell mouth peripheral wall 31.

FIG. 7 is an enlarged schematic diagram showing a second example of the shielding wall portion 20. As shown in FIG. As shown in FIG. 7, when the shielding wall portion 20 is formed integrally with the first side wall 4a1, the shielding wall portion 20 may be formed in a line along the rotation axis RS from the first side wall 4a1 to the impeller 2.地extended. In other words, the wall surface of the shielding wall portion 20 constituting the wall on the flow path side of the air flow and the wall surface of the first side wall 4a1 constituting the wall on the flow path side of the air flow may form the same plane. 7, in the cross section along the rotation axis RS, although the thickness of the first side wall 4a1 is equal to the thickness of the shielding wall portion 20, the thickness of the first side wall 4a1 is equal to the thickness of the shielding wall portion 20 , Can be the same thickness, or, can also be different thickness.

FIG. 8 is an enlarged schematic diagram showing a third example of the shielding wall portion 20. As shown in FIG. As shown in FIG. 8, when the shielding wall portion 20 is formed integrally with the first side wall 4a1, the shielding wall portion 20 may be formed to extend from the first side wall 4a1 to the impeller 2 in a cross section along the rotation axis RS. Furthermore, as shown in FIG. 8, the shielding wall portion 20 may have an inclined surface portion 20c between the first side wall 4a1 and the tip portion 20a. The inclined surface portion 20c protrudes from the first side wall 4a1 to form the side surface shape of the conical seat. The inclined surface part 20c is formed in the cross section along the rotation axis RS, and forms the inclined surface inclined with respect to the axial direction of the rotation axis RS. The shielding wall portion 20 has an inclined surface portion 20c, whereby in the axial direction of the rotating shaft RS, the formation position of the tip portion 20a is different from the formation position of the first side wall 4a1. That is, the wall surface of the shielding wall portion 20 of the wall constituting the flow path of the airflow and the wall surface of the first side wall 4a1 of the wall constituting the flow path of the airflow are formed with a gap.

FIG. 9 is an enlarged schematic diagram showing a fourth example of the shielding wall portion 20. As shown in FIG. As shown in FIGS. 6 to 8, the shielding wall portion 20 is formed integrally with the first side wall 4a1. In addition, the shielding portion 20 is not limited to the structure integrally formed with the first side wall 4a1. For example, as shown in FIG. 9, the shielding wall portion 20 may be formed integrally with the bell mouth peripheral wall 31.

As shown in FIG. 9, when the shielding wall portion 20 is integrally formed with the bell mouth peripheral wall 31, the shielding wall portion 20 protrudes from the bell mouth peripheral wall 31, in the radial direction of the impeller 2, from the bell mouth peripheral wall 31 to the inner peripheral edge. 32b extension. That is, the outer peripheral edge portion side of the shielding wall portion 20 is integrally formed with the bell mouth peripheral wall 31, and the shielding wall portion 20 is formed in the radial direction of the impeller 2 and extends from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. The shielding wall portion 20 integrally formed with the bell mouth peripheral wall 31 may have the above-mentioned drop portion 20b or the inclined surface portion 20c.

The shielding wall portion 20 is formed of a foamed material such as expanded styrene. In addition, the shielding wall portion 20 is not limited to being formed of a foam material. For example, the shielding portion 20 may be formed of a resin material, or may be formed of a metal material.

[Operation example of centrifugal fan 1] When the impeller 2 rotates, the air outside the scroll shell 4 is sucked into the scroll shell 4 through the suction port 5. At this time, the air sucked into the interior of the scroll shell 4 is guided by the bell mouth 3 to be sucked into the space 47 formed by the impeller 2. The air sucked into the space 47 formed by the impeller 2 becomes an air flow to which dynamic pressure and static pressure are added in the process of passing through the plurality of blades 2d, and is blown out to the radially outer side of the impeller 2.

When the air blown from the impeller 2 is trapped in the scroll portion 41 and guided between the inner side of the peripheral wall 4c and the blade 2d, the dynamic pressure system is converted to static pressure. After passing through the scroll portion 41, it is The discharge port 42a formed in the discharge part 42 is blown out of the scroll shell 4. In addition, the air blown from the impeller 2 has a velocity distribution in the axial direction of the rotating shaft RS of the impeller 2, and is offset to the side plate 2c side of the impeller 2 in the environment in which it is used.

[The effect of centrifugal fan 1] Fig. 10 is a schematic diagram showing the air flow in the centrifugal fan 1 of the first embodiment. First, as described above, the scroll casing 4 of the centrifugal fan 1 is located in the radial direction of the impeller 2 and has a shielding wall provided between the bell mouth peripheral wall 31 and the inner peripheral edge portion 32b and extending from the side wall 4a to the impeller 2 side部20。 Section 20. Furthermore, the distance D1 between the shielding wall portion 20 and the side plate 2c is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

The air flow FA flowing out of the impeller 2, as shown in FIG. 10, is blocked by the shielding wall portion 20 having this structure to prevent the flow in the direction of flowing into the impeller 2 and along the shielding wall portion extending in the radial direction of the impeller 2 20 mobile. In addition, the air flow FA is the air blown from the impeller 2 and shifts to the side plate 2c side of the impeller 2, and it is the air blown from the vicinity of the side plate 2c.

The air flow FA flowing out of the impeller 2 is prevented from flowing into the impeller 2 again by the shielding portion 20. The air flow FA flowing out of the impeller 2 suppresses the flow into the impeller 2 again. Therefore, the air flow FA flowing out of the impeller 2 does not collide with the fan blade 2d, and generates noise as the wind cutting sound of the fan blade 2d. Therefore, the centrifugal fan 1 having the shielding portion 20 can prevent the air flow FA flowing out of the impeller 2 from flowing into the impeller 2 and at the same time suppress the noise generated by the air flow.

In addition, the air flow FA flowing out of the impeller 2 is prevented from flowing into the direction of the impeller 2 and flows along the shielding wall portion 20 extending in the radial direction of the impeller 2. Therefore, the air flow FA that is prevented from flowing by the shielded wall portion 20 does not interfere with the other air flow FB and the air flow FC flowing out from the impeller 2. Moreover, the noise caused by the interference of the air flow FA that is prevented from flowing by the shielded wall portion 20 and the air flow FB and the air flow FC flowing out of the impeller 2 will not be generated. Therefore, the centrifugal fan 1 having the shielding portion 20 prevents the airflow flowing out of the impeller 2 from flowing into the impeller 2, and at the same time suppresses noise generated by the airflow.

Fig. 11 is a schematic diagram showing the air flow in the centrifugal fan 1L of the first comparative example. The scroll casing 4L of the centrifugal fan 1L of the comparative example does not have the shielding wall portion 20. In the centrifugal fan 1L, the air blown from the impeller 2 has a velocity distribution in the axial direction of the rotating shaft RS of the impeller 2, and is offset to the side plate 2c side of the impeller 2 in the environment in which it is used. At this time, a part of the airflow VR is countercurrent and does not flow in the inner space 45 of the scroll shell 4, but passes through the gap space 48 between the side wall 4a and the side plate 2c, passes through the inner side of the bell mouth 3, and flows into the impeller 2 again. internal. As a result, the air flow flowing in the scroll shell 4 leaks, and the air flow VR flowing along the inner side of the bell mouth 3 flows into the interior of the impeller 2 to collide with the fan blade 2d, and the result is a fan blade 2d. The loud noise of wind cutting.

FIG. 12 is a schematic diagram showing the air flow in the centrifugal fan 1R of the second comparative example. The scroll casing 4R of the centrifugal fan 1R of the comparative example does not have the shielding wall portion 20 and is provided with a backflow prevention plate 120 extending in the axial direction of the rotating shaft RS of the impeller 2. The centrifugal fan 1R of the comparative example uses the backflow prevention plate 120 extending in the axial direction of the rotating shaft RS of the impeller 2, and the countercurrent airflow BR is bent in the axial direction of the rotating shaft RS. Therefore, the reverse flow of the airflow BR that is bent toward the axial direction of the rotating shaft RS and flows along the backflow prevention plate 120 may hinder the flow of the airflow BA flowing out of the impeller 2. In addition, the reverse flow of the airflow BR flowing along the backflow prevention plate 120 that is bent toward the axial direction of the rotating shaft RS interferes with the airflow BA flowing from the impeller 2 and may generate noise.

On the other hand, in the centrifugal fan 1 of the first embodiment, as shown in FIG. 10, the air flow FA flowing out of the impeller 2 is flowed in the direction of the impeller 2 through the shielding wall 20 having this structure. Stop, and flow along the shielding wall portion 20 extending in the radial direction of the impeller 2. As a result, the centrifugal fan 1 can prevent the air flow FA flowing out of the impeller 2 from flowing into the impeller 2 and at the same time suppress the noise generated by the air flow. In addition, the air flow FA flowing out of the impeller 2 flows along the shielding wall portion 20, and therefore, the shielding wall portion 20 does not generate an air flow that interferes with the flow of air blown from the impeller 2.

In addition, this shielding wall portion 20 is located in the axial direction of the rotation axis RS of the main plate 2a, and is provided closer to the outer peripheral edge portion 32a than the main plate side end 2c1 of the side plate 2c. In this case, the shielding wall portion 20 does not hinder the flow of the air flow blown from the impeller 2. Therefore, the centrifugal fan 1 with the shielding portion 20 can prevent the air flow flowing out of the impeller 2 from flowing into the impeller 2 and at the same time suppress the noise generated by the air flow.

In addition, the shielding wall portion 20 is located in the radial direction of the impeller 2 and faces the side plate 2c. Therefore, the shielding wall portion 20 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b can reduce the clearance space 48 between the side wall 4a and the side plate 2c shown in the first comparative example. Therefore, the air flow FA flowing out of the impeller 2, as shown in FIG. 10, is prevented from flowing into the direction of the impeller 2 by the shielding wall portion 20 having this structure, and extends along the radial direction of the impeller 2. The shielding portion 20 flows. As a result, the centrifugal fan 1 can prevent the air flow FA flowing out of the impeller 2 from flowing into the impeller 2 and at the same time suppress the noise generated by the air flow.

In addition, the tip portion 20a has an inclined portion 20a1 in which the wall surface on the side of the main plate 2a forms an inclined surface. In addition, the wall surface on the side of the main plate 2a is a surface in contact with the air blown from the impeller 2. In order to ensure the strength, the shielding portion 20 preferably has as much thickness as possible in the axial direction of the rotating shaft RS. However, when the shielding wall portion 20 has a thickness in the axial direction of the rotating shaft RS, the tip portion 20a may obstruct the flow of air blown from the impeller 2 because of the position of the tip portion 20a. When the tip portion 20a has the inclined portion 20a1, the air blown from the impeller 2 easily flows along the inclined surface of the inclined portion 20a1. Therefore, the shielding wall portion 20 has the inclined portion 20a1, so that the air blown out from the impeller 2 can flow easily.

In addition, the shielding wall portion 20 is formed in a ring shape in a plan view viewed in the axial direction of the rotating shaft RS. Therefore, the centrifugal fan 1 can determine the direction of the discharge port 42a regardless of the larger part and the smaller part of the flow rate of the air flowing into the suction port 5.

In addition, the shielding wall portion 20 is formed integrally with the side wall 4a. With this structure, the scroll shell 4 can reduce the number of parts and make assembly easier. In addition, the scroll shell 4 has this structure, so that costs such as manufacturing costs and material costs can be reduced.

Alternatively, the shielding portion 20 is formed integrally with the bell mouth peripheral wall 31. With this structure, the shielding wall portion 20 of the scroll shell 4 can reduce the number of parts and make assembly easier. In addition, the scroll shell 4 system shielding wall portion 20 has this structure, so that costs such as manufacturing costs and material costs can be reduced.

In addition, the scroll shell 4 is formed of a foam material. With this structure, the scroll casing 4 can reduce the weight of the centrifugal fan 1. In addition, the scroll shell 4 has this structure, which makes it easier to shape. In addition, the scroll shell 4 has this structure, so that costs such as manufacturing costs and material costs can be reduced.

In addition, the shielding wall portion 20 is formed of a foam material. The scroll casing 4 is the shielding wall portion 20 having this structure, so that the centrifugal fan 1 can be reduced in weight. In addition, the scroll shell 4 system shielding wall portion 20 has this structure, so that it can be molded relatively easily. In addition, the scroll shell 4 system shielding wall portion 20 has this structure, so that costs such as manufacturing costs and material costs can be reduced.

In addition, the centrifugal fan 1 further includes a driving device 6 that imparts a driving force to the impeller 2. Even if the centrifugal fan 1 is provided with the driving device 6 inside, it can prevent the air flow FA flowing out of the impeller 2 from flowing into the impeller 2 and at the same time suppress the noise generated by the air flow.

Implementation form 2. [Centrifugal fan 1A] Fig. 13 is an enlarged view of the centrifugal fan 1A of the second embodiment. The centrifugal fan 1A shown in FIG. 13 is an enlarged view of a part of the range AR of the centrifugal fan 1 shown in FIG. 3. In addition, parts having the same structure as that of the centrifugal fan 1 in FIGS. 1 to 12 are given the same reference numerals, and the description thereof is omitted. The centrifugal fan 1A of the second embodiment is different in the shape of the shielding wall portion 20 in the centrifugal fan 1 of the first embodiment. Therefore, in the following description, using FIG. 13, the shielding wall portion 21 of the centrifugal fan 1A of the second embodiment will be described centering on the difference from the shielding wall portion 20 of the centrifugal fan 1 of the first embodiment.

(Wall part 21) The scroll shell 4 is in the radial direction of the impeller 2 and has a shielding wall portion 21 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. The shielding wall 21 prevents the air flow flowing out of the impeller 2 and then flowing into the direction of the impeller 2. The shielding wall 21 is formed of a foamed material such as expanded styrene. In addition, the shielding wall 21 is not limited to being formed of a foam material. For example, the shielding portion 21 may be formed of a resin material, or may be formed of a metal material.

Furthermore, the shielding portion 21 may be a structure of one member, or may be constructed by combining two or more members. For example, the shielding portion 21 may be formed of a single member by using a foam material, a resin material, or a metal material. Alternatively, the shielding wall portion 21 may be configured by the shielding wall portion 20 and a filling member 21a that fills the space between the shielding wall portion 20 and the air intake portion 32. Although the filling member 21a is desirably the same member as the shielding wall portion 21, it may be a different member. The filling member 21a is, for example, a foam material, a resin material, or a metal material.

As shown in FIG. 13, the shielding wall part 21 is formed in a block shape in the cross section along the rotation axis RS. The shielding wall portion 21 is in the axial direction of the rotating shaft RS, and abuts against the air intake portion 32. Moreover, as shown in FIG. 13, the shielding part 21 is formed so that it may extend in the vertical direction with respect to the rotation axis RS.

As shown in FIG. 13, the shielding wall 21 is located in the axial direction of the rotation axis RS of the main plate 2a, and is provided closer to the outer peripheral edge than the main plate side end 2c1 that becomes the end of the main plate 2a side of the side plate 2c. 32a side. That is, the shielding wall portion 21 is formed between the position of the main plate-side end portion 2c1 and the position of the outer peripheral edge portion 32a in a direction parallel to the axial direction of the rotation axis RS of the main plate 2a.

The shielding wall 21 is located in the radial direction of the impeller 2 and faces the side plate 2c. For example, as shown in FIG. 13, the shielding wall portion 21 is formed such that a part of the tip portion 20 a forming the edge portion of the inner peripheral side of the shielding wall portion 21 and the side plate 2 c are opposed to each other in the radial direction of the impeller 2. Here, in the radial direction of the impeller 2, the distance between the shielding wall portion 21 and the side plate 2c is regarded as the distance D1. The distance D1 is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c. Furthermore, the distance D1 is formed to be smaller than the distance between the bell mouth peripheral wall 31 and the side plate 2c. Furthermore, the tip portion 20a may have an inclined portion 20a1.

In the second embodiment, the scroll casing 4 has a shielding wall portion 21 extending from the bell mouth peripheral wall 31 to the side plate 2c in a cross section along the rotation axis RS. Moreover, regardless of the positional relationship between the end portion of the bell mouth peripheral wall 31 on the first side wall 4a1 side and the side plate 2c of the impeller 2, the distance D1 between the tip portion 20a and the side plate 2c is smaller than the distance between the peripheral wall 4c and the side plate 2c and the horn The distance between the mouth wall 31 and the side plate 2c.

[The effect of centrifugal fan 1A] The shielding wall portion 21 is in the axial direction of the rotating shaft RS, and abuts against the air intake portion 32. Therefore, as shown in FIG. 13, the shielding wall part 21 is formed in a block shape in the cross section along the rotation axis RS. The shielding wall portion 21 has a thickness in the axial direction of the rotating shaft RS in comparison with the shielding wall portion 20, thereby ensuring that the strength is greater than that of the shielding wall portion 20.

In addition, the centrifugal fan 1A has the shielding portion 21, whereby it can prevent the airflow flowing out of the impeller 2 from flowing into the impeller 2 as in the case of having the shielding portion 20, and at the same time, it can suppress The noise produced.

Implementation mode 3. [Centrifugal fan 1B] Fig. 14 is an enlarged view of the centrifugal fan 1B of the third embodiment. The centrifugal fan 1B shown in FIG. 14 is an enlarged view of a part of the range AR of the centrifugal fan 1 shown in FIG. 3. In addition, parts having the same structure as that of the centrifugal fan 1 in FIGS. 1 to 13 and the like are given the same reference numerals, and the description thereof is omitted. The centrifugal fan 1B of the third embodiment is different in the shape of the shielding wall portion 20 in the centrifugal fan 1 of the first embodiment. Therefore, in the following description, using FIG. 14, the shielding portion 22 of the centrifugal fan 1B of the third embodiment will be described centering on the difference from the shielding portion 20 of the centrifugal fan 1 of the first embodiment.

(Wall part 22) As shown in FIG. 14, the scroll casing 4 is in the radial direction of the impeller 2 and has a shielding wall portion 22 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32 b. The shielding wall 22 prevents the air flow flowing out of the impeller 2 and flowing in the direction of the impeller 2 again. The shielding wall portion 22 is formed of the same material as the shielding wall portion 20.

The shielding wall portion 22 is formed in an annular shape in a plan view viewed in a direction parallel to the axial direction of the rotating shaft RS. In addition, the shielding wall portion 22 is viewed in a plan view in a direction parallel to the axial direction of the rotating shaft RS, and is not limited to being formed in an annular shape, and it may be formed in an arc shape.

As shown in FIG. 14, the shielding wall part 22 is formed in a plate shape in the cross section along the rotation axis RS. In addition, the shielding wall portion 22 is not limited to a structure formed in a plate shape. For example, the shielding portion 22 may be formed in a block shape having a thickness in the axial direction of the rotating shaft RS. The shielding portion 22 may have an inclined portion 20a1.

As shown in FIG. 14, the shielding wall part 22 is formed in a plate shape, and is formed so that it may extend in the perpendicular direction with respect to the rotation axis RS. Moreover, the extending direction of the shielding portion 22 is not limited to a direction perpendicular to the rotation axis RS, and it may also be a direction inclined with respect to the direction perpendicular to the rotation axis RS. That is, the shielding wall portion 22 may be formed in a shape that is inclined with respect to a direction perpendicular to the rotation axis RS in a cross section along the rotation axis RS. However, the shielding portion 22 does not include a shape formed to extend in a direction parallel to the rotation axis RS.

As shown in FIG. 14, the shielding wall 22 is located in the axial direction of the rotation axis RS of the main plate 2a, and is provided closer to the outer peripheral edge than the main plate side end 2c1 that becomes the end of the main plate 2a side of the side plate 2c. 32a side. That is, the shielding wall portion 22 is formed between the position of the main plate-side end portion 2c1 and the position of the outer peripheral edge portion 32a in a direction parallel to the axial direction of the rotation axis RS of the main plate 2a.

The shielding wall 22 is formed in a plate shape, and faces the side plate 2c in the axial direction of the rotating shaft RS. In other words, the shielding wall portion 22 is formed in a plate shape, and the tip portion 22a and the side plate 2c forming the inner peripheral edge of the shielding wall portion 22 are tied in the radial direction of the impeller 2 and do not face each other. The tip portion 22a of the shielding wall portion 22 is located in the radial direction of the impeller 2 and is located closer to the rotating shaft RS than the side plate 2c. The centrifugal fan 1B is viewed in a plan view parallel to the axial direction of the rotating shaft RS. From the shaft side of the rotating shaft RS to the outside, an inner peripheral edge portion 32b, a tip portion 22a, a side plate 2c, and a bell mouth peripheral wall 31 are sequentially arranged. .

Here, in the direction parallel to the axial direction of the rotation axis RS, the distance between the shielding wall portion 22 and the side plate 2c is regarded as the distance D2. In more detail, in the direction parallel to the axial direction of the rotating shaft RS, the distance between the facing surface 22b of the shielding wall portion 22 facing the impeller 2 and the side plate 2c is taken as the distance D2. The distance D2 is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c. Moreover, the distance D2 is formed to be smaller than the distance between the bell mouth peripheral wall 31 and the side plate 2c.

In the third embodiment, the scroll casing 4 has a shielding wall portion 22 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b in a cross section along the rotation axis RS. Regardless of the positional relationship between the end portion of the bell mouth peripheral wall 31 on the first side wall 4a1 side and the side plate 2c of the impeller 2, the distance D2 between the facing surface 22b of the shielding wall portion 22 and the side plate 2c is smaller than that of the peripheral wall 4c and the side plate. The distance between 2c and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

[The effect of centrifugal fan 1B] The scroll casing 4 of the centrifugal fan 1B has a shielding wall 22. In the radial direction of the impeller 2, there is a shielding wall portion 22 provided between the bell mouth peripheral wall 31 and the inner peripheral edge portion 32b and extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. Furthermore, this shielding wall portion 22 is located in the axial direction of the rotating shaft RS, and faces the side plate 2c. In addition, the distance D2 between the shielding wall 22 and the side plate 2c is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

The centrifugal fan 1B has the shielding wall 22 of this structure, thereby preventing the air blown from the impeller 2 from flowing in the direction of flowing into the impeller 2 again. Therefore, the air flow out of the impeller 2 and then flow into the impeller 2 is suppressed. Therefore, the air flow out of the impeller 2 will not collide with the fan blade 2d and generate noise as the wind cutting sound of the fan blade 2d. . Therefore, the centrifugal fan 1B having the shielding portion 22 can prevent the air flow flowing out of the impeller 2 from flowing into the impeller 2, and at the same time, the noise generated by the air flow can be suppressed.

In addition, the air flow out of the impeller 2 is prevented from flowing in the direction of the impeller 2 and flows along the shielding wall 22 extending in the radial direction of the impeller 2. Therefore, the air flow that is prevented from flowing by the shielding wall portion 22 does not interfere with other air flows flowing out of the impeller 2. Therefore, there is no noise caused by the interference of the air flow that is prevented from flowing by the shielding wall portion 22 and the air flow out of the impeller 2. As a result, the centrifugal fan 1B can prevent the airflow flowing out of the impeller 2 from flowing into the impeller 2 and at the same time suppress the noise generated by the airflow.

Implementation mode 4. 〔Centrifugal fan 1C〕 Fig. 15 is an enlarged view of the centrifugal fan 1C of the fourth embodiment. The centrifugal fan 1C shown in FIG. 15 is an enlarged view of a part of the range AR of the centrifugal fan 1 shown in FIG. 3. In addition, parts having the same structure as the centrifugal fan 1 of FIGS. 1 to 14 and the like are given the same reference numerals, and the description thereof is omitted. The centrifugal fan 1C of the fourth embodiment is different in the shape of the shielding wall 22 in the centrifugal fan 1B of the third embodiment. Therefore, in the following description, using FIG. 15, the shielding wall portion 23 of the centrifugal fan 1C of the fourth embodiment will be described centering on the difference from the shielding wall portion 22 of the centrifugal fan 1B of the third embodiment.

(Wall part 23) The scroll shell 4 is in the radial direction of the impeller 2 and has a shielding wall portion 23 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. The shielding wall 23 prevents the air flow flowing out of the impeller 2 from flowing in the direction of flowing into the impeller 2 again. The shielding wall 23 is formed of a foamed material such as expanded styrene. In addition, the shielding wall portion 23 is not limited to being formed of a foam material. For example, the shielding portion 23 may be formed of a resin material, or may be formed of a metal material.

Moreover, the shielding wall portion 23 may be a structure of one member, or may be a combination of two or more members. For example, the shielding wall portion 23 may be formed of a single member by using a foam material, a resin material, or a metal material. Alternatively, the shielding wall portion 23 is constituted by the shielding wall portion 22 and a filling member 23a that fills the space between the shielding wall portion 22 and the air intake portion 32. Although the filling member 23a is desirably the same member as the shielding wall portion 22, it may be a different member. The filling member 23a is, for example, a foam material, a resin material, or a metal material.

As shown in FIG. 15, the shielding wall part 23 is formed in a block shape in the cross section along the rotation axis RS. The shielding wall portion 23 is in the axial direction of the rotating shaft RS and abuts against the air intake portion 32. Moreover, as shown in FIG. 15, the shielding part 23 is formed so that it may extend in the perpendicular direction with respect to the rotation axis RS. Furthermore, the tip portion 22a may have an inclined portion 20a1.

As shown in FIG. 15, the shielding wall 23 is in the axial direction of the rotation axis RS of the main plate 2a, and is provided closer to the outer peripheral edge than the main plate side end 2c1 that becomes the end of the main plate 2a side of the side plate 2c. 32a side. That is, the shielding wall portion 23 is formed between the position of the main plate side end portion 2c1 and the position of the outer peripheral edge portion 32a in a direction parallel to the axial direction of the rotation axis RS of the main plate 2a.

Here, in the direction parallel to the axial direction of the rotating shaft RS, the distance between the shielding wall portion 23 and the side plate 2c is taken as the distance D2. More specifically, in the direction parallel to the axial direction of the rotating shaft RS, the distance between the facing surface 22b of the shielding wall 23 facing the impeller 2 and the side plate 2c is taken as the distance D2. The distance D2 is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c. Moreover, the distance D2 is formed to be smaller than the distance between the bell mouth peripheral wall 31 and the side plate 2c.

In the fourth embodiment, the scroll shell 4 has a shielding wall portion 23 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b in a cross section along the rotation axis RS. Moreover, regardless of the positional relationship between the end portion of the bell mouth peripheral wall 31 on the first side wall 4a1 side and the side plate 2c of the impeller 2, the distance D2 between the facing surface 22b of the shielding wall portion 23 and the side plate 2c is smaller than the peripheral wall 4c and the side plate The distance between 2c and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

[The effect of centrifugal fan 1C] The shielding wall portion 23 is in the axial direction of the rotating shaft RS and abuts against the air intake portion 32. Therefore, as shown in FIG. 15, the shielding wall portion 23 is formed in a block shape in a cross section along the rotation axis RS. Comparing the shielding wall portion 23 with the shielding wall portion 22, by having a thickness in the axial direction of the rotating shaft RS, the strength can be ensured to be greater than that of the shielding wall portion 22.

In addition, the centrifugal fan 1C has a shielding wall 23, which, like the case of having the shielding wall 22, can prevent the airflow flowing out of the impeller 2 from flowing into the impeller 2, and at the same time, it can suppress the airflow generated by the airflow. noise.

Implementation mode 5. [Centrifugal fan 1D] Fig. 16 is an enlarged view of the centrifugal fan 1D of the fifth embodiment. The centrifugal fan 1D shown in FIG. 16 is an enlarged view of a part of the range AR of the centrifugal fan 1 shown in FIG. 3. In addition, parts having the same structure as the centrifugal fan 1 of FIGS. 1 to 15 and the like are given the same reference numerals, and the description thereof is omitted. The centrifugal fan 1D of the fifth embodiment is different in the shape of the shielding wall 22 in the centrifugal fan 1B of the third embodiment. Therefore, in the following description, referring to FIG. 16, the shielding wall portion 24 of the centrifugal fan 1D of the fifth embodiment will be described centering on the difference from the shielding wall portion 22 of the centrifugal fan 1B of the third embodiment.

(Wall part 24) The scroll shell 4 is in the radial direction of the impeller 2 and has a shielding wall portion 24 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. The shielding wall portion 24 prevents the air flow flowing out of the impeller 2 from flowing in the direction of flowing into the impeller 2 again.

The shielding wall portion 24 is formed in a plate shape, and the tip portion 22 a of the shielding wall portion 24 is arranged in the radial direction of the impeller 2 and abuts against the air intake portion 32.

Here, in the direction parallel to the axial direction of the rotation axis RS, the distance between the shielding wall portion 24 and the side plate 2c is taken as the distance D2. In more detail, in the direction parallel to the axial direction of the rotating shaft RS, the distance between the facing surface 22b of the shielding wall portion 24 facing the impeller 2 and the side plate 2c is taken as the distance D2. The distance D2 is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c. Moreover, the distance D2 is formed to be smaller than the distance between the bell mouth peripheral wall 31 and the side plate 2c.

In the fifth embodiment, the scroll casing 4 has a shielding wall portion 24 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b in a cross section along the rotation axis RS. Moreover, regardless of the positional relationship between the end portion of the bell mouth peripheral wall 31 on the first side wall 4a1 side and the side plate 2c of the impeller 2, the distance D2 between the facing surface 22b of the shielding wall portion 24 and the side plate 2c is smaller than that of the peripheral wall 4c and the side plate. The distance between 2c and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

[The effect of centrifugal fan 1D] The shielding wall portion 24 is in the radial direction of the impeller 2 and abuts against the air intake portion 32. Therefore, the shielding wall portion 24 has an increased abutting position compared with the shielding wall portion 22, and therefore, it is possible to ensure that the strength is greater than that of the shielding wall portion 22.

In addition, the centrifugal fan 1D is provided with the shielding wall portion 24, which can prevent the airflow flowing out of the impeller 2 from flowing into the impeller 2 as in the case of having the shielding wall portion 22, and at the same time, it can suppress the airflow generated by the airflow. noise.

Embodiment 6. 〔Centrifugal fan 1E〕 Fig. 17 is an enlarged view of the centrifugal fan 1E of the sixth embodiment. The centrifugal fan 1E shown in FIG. 17 is an enlarged view of a part of the range AR of the centrifugal fan 1 shown in FIG. 3. In addition, the parts having the same configuration as the centrifugal fan 1 of FIGS. 1 to 16 are given the same reference numerals, and the description thereof will be omitted. The centrifugal fan 1E of the fifth embodiment is different in the shape of the shielding wall 22 in the centrifugal fan 1B of the third embodiment. Therefore, in the following description, using FIG. 17, the shielding wall portion 25 of the centrifugal fan 1E of the sixth embodiment will be described centering on the difference from the shielding wall portion 22 of the centrifugal fan 1B of the third embodiment.

(Wall part 25) The scroll shell 4 is in the radial direction of the impeller 2 and has a shielding wall portion 25 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b. The shielding wall 25 prevents the airflow flowing out of the impeller 2 from flowing in the direction of flowing into the impeller 2 again. The shielding portion 25 is formed of a foamed material such as expanded styrene. In addition, the shielding portion 25 is not limited to being formed of a foam material. For example, the shielding portion 25 may be formed of a resin material, or may be formed of a metal material.

In addition, the shielding wall portion 25 may be constituted by one member, or may be constituted by combining two or more members. For example, the shielding portion 25 may be formed of a single member by using a foam material, a resin material, or a metal material. Alternatively, the shielding wall portion 25 may be configured by the shielding wall portion 22 and a filling member 25a that fills the space between the shielding wall portion 22 and the air intake portion 32. Although the filling member 25a is desirably the same member as the shielding wall portion 22, it may be a different member. The filling member 25a is, for example, a foam material, a resin material, or a metal material.

As shown in FIG. 17, the shielding wall part 25 is formed in a block shape in the cross section along the rotation axis RS. The shielding wall portion 25 is in the axial direction of the rotating shaft RS and abuts against the air intake portion 32. Moreover, as shown in FIG. 17, the shielding part 25 is formed so that it may extend in the perpendicular direction with respect to the rotation axis RS. The tip portion 22 a of the shielding wall portion 25 is in the radial direction of the impeller 2 and abuts against the air intake portion 32.

Here, in the direction parallel to the axial direction of the rotation axis RS, the distance between the shielding wall portion 25 and the side plate 2c is taken as the distance D2. More specifically, in the direction parallel to the axial direction of the rotating shaft RS, the distance between the facing surface 22b of the shielding wall portion 25 facing the impeller 2 and the side plate 2c is taken as the distance D2. The distance D2 is formed to be smaller than the distance between the peripheral wall 4c and the side plate 2c. Moreover, the distance D2 is formed to be smaller than the distance between the bell mouth peripheral wall 31 and the side plate 2c.

In the sixth embodiment, the scroll casing 4 has a shielding wall portion 25 extending from the bell mouth peripheral wall 31 to the inner peripheral edge portion 32b in a cross section along the rotation axis RS. The shielding wall 25 fills the space formed by the bell mouth 3 on the side facing the impeller 2. Moreover, regardless of the positional relationship between the end portion of the bell mouth peripheral wall 31 on the first side wall 4a1 side and the side plate 2c of the impeller 2, the distance D2 between the facing surface 22b of the shielding wall portion 25 and the side plate 2c is smaller than the peripheral wall 4c and the side plate The distance between 2c and the distance between the bell mouth peripheral wall 31 and the side plate 2c.

[The effect of centrifugal fan 1E] The shielding wall portion 25 is in the axial direction of the rotating shaft RS and abuts against the air intake portion 32. Therefore, as shown in FIG. 17, the shielding wall part 25 is formed in a block shape in the cross section along the rotation axis RS. The shielding wall portion 25 has a thickness in the axial direction of the rotating shaft RS in comparison with the shielding wall portion 23, thereby ensuring that the strength is greater than that of the shielding wall portion 23.

In addition, the centrifugal fan 1E has the shielding wall portion 25, whereby it can prevent the airflow flowing out of the impeller 2 from flowing into the impeller 2 as in the case of having the shielding wall portion 23, and at the same time, it can suppress The noise produced.

Implementation mode 7. [Centrifugal fan 1F] Fig. 18 is a schematic cross-sectional view of a centrifugal fan 1F of the seventh embodiment. FIG. 18 schematically shows a cross-section of the scroll shell 4. In addition, parts having the same structure as that of the centrifugal fan 1 in FIGS. 1 to 17 are given the same reference numerals, and the description thereof will be omitted. In contrast to the centrifugal fan 1 of the first embodiment, which is a single suction fan that sucks air from one side of the scroll case 4, the centrifugal fan 1F of the seventh embodiment takes in air from both sides of the scroll case 4. Double suction fan for air.

The centrifugal fan 1F is a double suction fan that sucks air from both sides of the scroll shell 4 in the axial direction of the virtual rotating shaft RS of the impeller 2F. The centrifugal fan 1F has an impeller 2 for generating airflow, and a scroll casing 4 for accommodating the impeller 2 inside.

(Impeller 2) As shown in Figure 18, the impeller 2 has: a main plate 2a, which is in the shape of a disc; a side plate 2c, which is in a ring shape, and is arranged opposite to the main plate 2a; It is connected to the side plate 2c, and is arranged on the peripheral edge portion 2a1 of the main plate 2a.

The main plate 2a may be plate-shaped, and it may be a shape other than a disk shape, such as a polygonal shape. Moreover, the main board 2a is not limited to being constituted by a single plate-shaped member, and it may be constituted by integrally fixing a plurality of plate-shaped members.

The plural fan blades 2d are located in the axial direction of the rotating shaft RS, and are provided on both sides of the main plate 2a. Similarly, the side plates 2c are located in the axial direction of the rotating shaft RS, and are respectively provided on both sides of the main plate 2a.

The impeller 2 is configured in a cylindrical shape by a plurality of blades 2d arranged on the main plate 2a. Furthermore, the impeller 2 is in the axial direction of the rotating shaft RS, and on the side plate 2c side opposite to the main plate 2a, a suction port 2e for inflowing gas into the space 47 enclosed by the main plate 2a and the plurality of blades 2d is formed. The impeller 2 is arranged on both sides of the plate surface constituting the main plate 2a, and blades 2d and side plates 2c are respectively arranged. On both sides of the plate surface constituting the main plate 2a, suction ports 2e of the impeller 2 are formed.

(Scroll Shell 4) The scroll casing 4 accommodates the impeller 2F for the centrifugal fan 1F inside, and rectifies the air blown from the impeller 2F. The scroll shell 4 has a scroll part 41 and a discharge part 42.

(Scroll 41) The scroll portion 41 forms an air path that converts the dynamic pressure of the air flow generated by the impeller 2F to static pressure. The scroll portion 41 has a side wall 4a and a peripheral wall 4c. (Side wall 4a) The side walls 4a are in the axial direction of the rotating shaft RS of the impeller 2F, and are arranged on both sides of the impeller 2F. A suction port 5 is formed on the side wall 4 a of the scroll shell 4 so that air can circulate between the impeller 2F and the outside of the scroll shell 4.

The centrifugal fan 1F is attached to the scroll case 4 and has two side walls 4a. The two side walls 4a are formed so as to interpose the peripheral wall 4c and face each other. More specifically, as shown in FIG. 18, the side wall 4 a of the scroll shell 4 has a first side wall 4 a 1 and a second side wall 4 a 21.

The first side wall 4a1 is formed along the first end 4c11 of one side of the peripheral wall 4c in the axial direction of the rotating shaft RS. A suction port 5 for taking in air is formed in the first side wall 4a1 so that the air can circulate between the impeller 2 and the outside of the scroll shell 4. The second side wall 4a21 is formed along the second end 4c12 of the other side of the peripheral wall 4c in the axial direction of the rotating shaft RS. A suction port 5 for taking in air is formed in the second side wall 4a21 so that the air can circulate between the impeller 2 and the outside of the scroll shell 4. The scroll casing 4 of the centrifugal fan 1F is arranged in the axial direction of the rotating shaft RS of the impeller 2 and on both sides of the main plate 2a, and has a double suction type casing with a side wall 4a formed with a suction port 5.

The first side wall 4a1 has a bell mouth 3 forming a suction port 5 communicating with a space 47 formed by the main plate 2a and the plurality of blades 2d. The suction port 5 provided in the first side wall 4a1 is formed by the bell mouth 3 as shown in FIG. Similarly, the second side wall 4a21 has a bell mouth 3 forming a suction port 5 communicating with the space 47 formed by the main plate 2a and the plurality of fan blades 2d. The suction port 5 provided in the second side wall 4a21 is formed by the bell mouth 3 as shown in FIG.

(Wall part 20) The scroll shell 4 is located in the axial direction of the rotating shaft RS, and has shielding wall portions 20 on both sides of the main plate 2a. That is, the shielding wall portion 20 has a first shielding wall portion 27 arranged on the side of the first side wall 4a1 and a second shielding wall portion 28 arranged on the side of the second side wall 4a21.

[The effect of centrifugal fan 1F] The centrifugal fan 1F has the first shielding wall portion 27 and the second shielding wall portion 28. Even if it is a double-suction fan, it can suppress the air flow out of the impeller 2 in the same way as the case with the shielding wall portion 20. When it flows into the impeller 2 again, the noise generated by the airflow can be suppressed at the same time.

Embodiment 8. [Air Conditioning Unit 60] Fig. 19 is a front side view schematically showing an example of the air conditioner 60 of the eighth embodiment. Fig. 20 is a perspective view schematically showing an example of the air conditioner 60 of the eighth embodiment. In addition, FIGS. 19 and 20 illustrate the internal structure of the air conditioner 60 through the frame 61. In addition, parts having the same configuration as the centrifugal fan 1 of FIGS. 1 to 18 and the like are given the same reference numerals, and the description thereof is omitted.

The air conditioner 60 of the eighth embodiment includes any one or more of the centrifugal fan 1 to the centrifugal fan 1F; the heat exchanger 10 is arranged at a position facing the discharge port 42a of the centrifugal fan 1, etc.; and a frame 61 for housing Centrifugal fan 1 and heat exchanger 10. In addition, in the following description, the case of the centrifugal fan 1 is shown as any one of the centrifugal fan 1 to the centrifugal fan 1F. The air-conditioning device 60 of the eighth embodiment is a floor-mounted type air-conditioning device 60, but the air-conditioning device 60 is not limited to a floor-mounted type. For example, the air conditioner 60 may be a ceiling-mounted air conditioner 60 or a wall-mounted air conditioner 60.

The frame 61 has a front surface portion 61a, a back surface portion 61b, a top surface portion 61c, a bottom surface portion 61d, a left side surface portion 61e, and a right side surface portion 61f, and is formed in a rectangular parallelepiped shape. Moreover, the shape of the tube body 61 is not limited to a rectangular parallelepiped shape. For example, it may be a cylindrical shape, a quadrangular prism shape, a cone shape, a shape having a plurality of corners, a shape having a plurality of curved surfaces, and other shapes.

In either or both of the left side surface 61e and the right side surface 61f, an intake port 61g for inflowing air into the housing 61 is formed. The suction port 61g is, for example, an elongated opening that is long in the vertical direction. The suction port 61g may be formed at a position perpendicular to the axial direction of the rotating shaft RS of the centrifugal fan 1. For example, the suction port 61g may be formed in the front surface portion 61a or the back surface portion 61b. The suction port 61g shown in FIG. 20 is an example, and the position, size, and shape of the suction port 61g are not limited to the structure of FIG. 20. A filter for removing dust in the air may be arranged at the suction port 61g.

In the upper part of the front surface portion 61a, there is formed a blow-out port 63 through which air that passes through the heat exchanger 10 for heat exchange flows out. The blowing port 63 is, for example, a rectangular opening. The blowing port 63 is provided with a plurality of blades 67 for controlling the wind direction. The structure of the blade 67 can adjust the wind direction up and down and left and right.

The inside of the frame 61 is formed with a first space 64 in which the centrifugal fan 1 is arranged, and a second space 65 in which the heat exchanger 10 is arranged. The first space 64 and the second space 65 are partitioned by a partition plate 62. The centrifugal fan 1 is installed on the partition plate 62.

The first space 64 is a space communicating with the outside of the housing 61 through the suction port 61 g, and is a space on the suction side of the centrifugal fan 1. The second space 65 is a space communicating with the outside of the frame 61 through the blowing port 63, and is a space on the blowing side of the centrifugal fan 1. The first space 64 and the second space 65 communicate with each other through the centrifugal fan 1. The impeller 2 of the centrifugal fan 1 forms a flow in which air is sucked into the housing 61 from the suction port 61g, and is blown out from the air outlet 63 to the air-conditioned space.

The heat exchanger 10 is arranged at a position facing the discharge port 42a of the centrifugal fan 1, and in the second space 65 of the frame 61, is arranged on the air path of the air discharged from the centrifugal fan 1. The heat exchanger 10 adjusts the temperature of the air sucked into the housing 61 from the suction port 61g and blown from the air outlet 63 to the air-conditioned space. In addition, the heat exchanger 10 can employ a well-known structure.

[Operation example of air conditioner 60] Driven by the driving device 6 shown in FIG. 3, when the impeller 2 rotates, the air in the air-conditioned space is sucked into the housing 61 through the suction port 61g. The air sucked into the inside of the frame 61 is guided by the bell mouth 3 and sucked by the impeller 2. The air sucked by the impeller 2 is blown out toward the radially outer side of the impeller 2. The air blown out from the impeller 2 passes through the inside of the scroll shell 4, is blown out from the discharge port 42 a of the scroll shell 4, and is supplied to the heat exchanger 10. When the air supplied to the heat exchanger 10 passes through the heat exchanger 10, it exchanges heat with the refrigerant flowing in the heat exchanger 10 to adjust the temperature and humidity. The air that has passed through the heat exchanger 10 is blown out from the air outlet 63 to the air-conditioned space.

[The effect of the air conditioning unit 60] The air conditioner 60 of the eighth embodiment includes the centrifugal fan 1 and the like of the first embodiment, so the same effects as the centrifugal fan 1 and the like of the first embodiment can be obtained. Therefore, the air conditioner 60 can suppress noise generated by the airflow in the centrifugal fan 1, for example.

Each of the above-mentioned Embodiments 1 to 8 can be implemented in combination with each other. In addition, the structure shown in the above embodiment is only an example, and it can be combined with other well-known technologies, and a part of the structure can be omitted or changed within the scope of not deviating from the gist.

1: Centrifugal fan 1A: Centrifugal fan 1B: Centrifugal fan 1C: Centrifugal fan 1D: Centrifugal fan 1E: Centrifugal fan 1F: Centrifugal fan 1L: Centrifugal fan 1R: Centrifugal fan 2: impeller 2F: Impeller 2a: Motherboard 2a1: peripheral part 2a2: center 2b: Shaft 2c: side panel 2c1: Motherboard side end 2d: fan blade 2e: suction port 3: Bell mouth 4: scroll shell 4L: scroll shell 4R: scroll shell 4a: side wall 4a1: 1st side wall 4a2: 2nd side wall 4a21: 2nd side wall 4c: peripheral wall 4c11: first end 4c12: 2nd end 5: suction port 6: Drive device 10: Heat exchanger 20: Wall part 20a: Tip 20a1: Inclined part 20b: Drop 20c: oblique face 21: Wall part 21a: Filling member 22: Wall part 22a: Tip 22b: Opposite side 23: Wall part 23a: Filling member 24: Wall part 25: Wall part 25a: Filling member 27: The first shelter 28: The second shelter 31: Bell mouth peripheral wall 32: Air intake part 32a: Outer peripheral edge 32b: inner peripheral edge 41: Scroll 41b: End of scroll 41s: the beginning of the scroll 42: vomiting part 42a: spit out 42b: Extension board 42c: diffuser 43: Tongue 45: internal space 46: Space 47: Space 48: Interstitial Space 60: Air-conditioning device 61: Frame 61a: Front surface part 61b: Back part 61c: Top face 61d: bottom face 61e: left face 61f: right face 61g: suction port 62: divider 63: Blow Out 64: first space 65: second space 67: blade 120: Backflow prevention board

[Fig. 1] is a perspective view schematically showing the centrifugal fan of the first embodiment. [Figure 2] is an outline view of the structure of the centrifugal fan of the first embodiment viewed parallel to the rotating shaft. [Figure 3] is a cross-sectional view schematically showing the A-A line section of the centrifugal fan shown in Figure 2. [Fig. 4] is an enlarged view of the range AR of the centrifugal fan shown in Fig. 3. [Fig. 5] is an enlarged view showing an example of the tip portion of the shielding wall portion. [Fig. 6] is an enlarged schematic diagram showing the first example of the shielding portion. [Figure 7] is an enlarged schematic view showing the second example of the shielding portion. [Fig. 8] is an enlarged schematic diagram showing the third example of the shielding portion. [Figure 9] is an enlarged schematic diagram showing the fourth example of the shielding portion. [Fig. 10] is a schematic diagram showing the air flow in the centrifugal fan in the first embodiment. [Fig. 11] is a schematic diagram showing the air flow in the centrifugal fan of the first comparative example. [Fig. 12] is a schematic diagram showing the air flow in the centrifugal fan of the second comparative example. [Figure 13] is an enlarged view of the centrifugal fan in the second embodiment. [Figure 14] is an enlarged view of the centrifugal fan in the third embodiment. [Figure 15] is an enlarged view of the centrifugal fan in the fourth embodiment. [Figure 16] is an enlarged view of the centrifugal fan in the fifth embodiment. [Figure 17] is an enlarged view of the centrifugal fan in the sixth embodiment. [Fig. 18] is a schematic cross-sectional view of the centrifugal fan in the seventh embodiment. [Fig. 19] is a front side view schematically showing an example of the air conditioner of Embodiment 8. [Fig. 20] is a perspective view schematically showing an example of the air conditioner of Embodiment 8.

1: Centrifugal fan

2: impeller

2a: Motherboard

2b: Shaft

2a1: peripheral part

2a2: center

2c: side panel

2c1: Motherboard side end

2d: fan blade

2e: suction port

3: Bell mouth

4: scroll shell

4a: side wall

4a1: 1st side wall

4a2: 2nd side wall

4c: peripheral wall

4c11: first end

4c12: 2nd end

5: suction port

6: Drive device

20: Wall part

20a: Tip

31: Bell mouth peripheral wall

32: Air intake part

32a: Outer peripheral edge

32b: inner peripheral edge

45: internal space

46: Space

47: Space

RS: Rotating axis

Claims (14)

A centrifugal fan, which includes: The impeller has: a main plate, which is driven to rotate; a side plate, which has a ring shape and is arranged opposite to the main plate; and a plurality of fan blades, one end is connected to the main plate, and the other end is connected to the side plate and arranged on the periphery of the main plate Department; and The scroll housing contains the impeller and has: a peripheral wall formed in a scroll shape; and a side wall having a bell mouth that forms a suction port communicating with the space formed by the main plate and the plurality of fan blades, The bell mouth system has: The peripheral wall of the bell mouth, which protrudes from the side wall, is formed into a cylindrical shape; and The air intake portion is formed in a ring shape, forming the outer peripheral edge portion of the outer peripheral side, and is continuous with the end of the protruding direction of the peripheral wall of the bell mouth, and the inner peripheral edge forming the inner peripheral edge portion forms the suction The mouth is formed so that the diameter of the opening gradually becomes smaller toward the inside of the scroll shell, The scroll shell system In the radial direction of the impeller, Having a shielding wall portion arranged between the bell mouth peripheral wall and the inner peripheral edge portion and extending from the side wall to the impeller side, The shelter system The distance between the shielding part and the side plate is It is formed to be smaller than the distance between the peripheral wall and the side plate, and the distance between the bell mouth peripheral wall and the side plate. Such as the centrifugal fan of claim 1, wherein the wall part is In the radial direction, it faces the side plate. Such as the centrifugal fan of claim 2, wherein the wall part is It has a tip that forms the edge on the inner peripheral side, The tip portion has an inclined portion where the wall surface on the main board side forms an inclined surface. Such as the centrifugal fan of claim 1, in which the wall part is In the axial direction of the rotating shaft of the impeller, it faces the side plate. The centrifugal fan according to any one of claims 1 to 4, wherein the shielding part is In the radial direction, it abuts against the air intake portion. The centrifugal fan according to any one of claims 1 to 4, wherein the shielding part is In the axial direction of the rotating shaft of the impeller, it abuts against the air intake portion. The centrifugal fan according to any one of claims 1 to 4, wherein the shielding part is When viewed in the axial direction of the rotating shaft of the impeller, it is formed in a ring shape. The centrifugal fan according to any one of claims 1 to 4, wherein the shielding part is It is integrally formed with the side wall. The centrifugal fan according to any one of claims 1 to 4, wherein the shielding part is It is integrally formed with the peripheral wall of the bell mouth. Such as the centrifugal fan of any one of claims 1 to 4, wherein the side wall is Having a first side wall and a second side wall that sandwich the peripheral wall to face each other, The first side wall and the second side wall are respectively formed with the bell mouth, The covering part has: The first shielding wall portion is arranged on the side of the first side wall; and The second shielding wall portion is arranged on the second side wall side. Such as the centrifugal fan of any one of claims 1 to 4, wherein the scroll shell is It is formed of foamed material. The centrifugal fan according to any one of claims 1 to 4, wherein the shielding part is It is formed of foamed material. The centrifugal fan according to any one of claims 1 to 4, which further includes a driving device that imparts a driving force to the impeller. An air conditioner, which includes: Centrifugal fan, any one of claims 1-13; and The heat exchanger is arranged at a position facing the outlet of the centrifugal fan.

Images