JP6997615B2 - Blower - Google Patents

Description

The present invention relates to, for example, a blower used in a vehicle air conditioner.

Conventionally, as a blower of this type, an annular portion connecting a plurality of blades extending in the direction of the rotation axis and one end in the axial direction of the plurality of blades at intervals around the rotation axis and the other end in the axial direction of the plurality of blades. An impeller having a substrate connecting the portions, and a casing provided with a circular suction port for sucking air on one end side in the axial direction and a spiral ventilation path formed on the radial outer side of the impeller housed inside. , Are known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-106708

In the blower, the air flowing into the casing from the suction port located on one end side in the axial direction is circulated by the impeller so that the flow direction is changed from the axial direction of the rotating shaft to the radial direction, and the air flows on the outer peripheral side of the impeller. It circulates in a swirl ventilation path. Therefore, in the blower, the air tends to flow unevenly toward the other end side in the axial direction of the impeller, and the flow rate of the air on the one end side in the axial direction of the impeller is reduced. Further, in the blower, the air flowing into the casing along the edge of the suction port is separated at one end side in the axial direction in the casing, and the air flow in the one end side in the axial direction in the casing is disturbed. In this case, in the blower, it is difficult to reduce the noise because the noise caused by the turbulence of the air flow is generated at one end side in the axial direction in the casing.

An object of the present invention is to provide a blower capable of improving quietness by suppressing turbulence of air flowing on the suction port side in the axial direction of an impeller.

In the present invention, in order to achieve the above object, a plurality of blades extending in parallel with the rotation axis at intervals around the rotation axis, an annular portion connecting one axial end portion of the plurality of blades, and a plurality of rings. An impeller having a substrate connecting the other ends in the axial direction of the blade and a circular suction port for sucking air on one end side in the axial direction are provided, and swirl ventilation is provided on the radial outer side of the impeller housed inside. A casing having a path formed therein is provided, and the opening edge portion of the suction port in the casing has an inner wall portion whose end portion extends toward the other end side in the axial direction, and the inner circumference of the tip portion of the inner wall portion. The center of the arc that continuously extends from the surface toward the other end in the axial direction and passes through the tip of the inner peripheral surface of the inner wall portion and the other end in the axial direction of the annular portion is the other end in the axial direction of the annular portion. The distance from the axially extending straight line passing through the axially opposite end of the annular portion to the center of the arc is the axial direction of the annular portion. It is within the range of 0.5 to 1.7 times the distance to the straight line extending in the axial direction through the other end.

As a result, the air flowing into the casing through the outer peripheral side of the suction port circulates along the inner peripheral surface of the opening edge and then circulates along the inner peripheral surface of the annular portion, and the wing and the wing Since it flows into the swirl ventilation path through the gap between them, the separation of the air flow flowing along the inner peripheral surface of the opening edge and the inner peripheral surface of the annular portion is suppressed, and the one end side in the axial direction of the impeller is suppressed. The generation of sound is suppressed.

According to the present invention, it is possible to suppress the separation of the air flow flowing along the inner peripheral surface of the opening edge portion and the inner peripheral surface of the annular portion, so that sound is generated on one end side in the axial direction of the impeller. It becomes possible to suppress it, and it becomes possible to improve quietness.

It is an overall perspective view of the blower which shows one Embodiment of this invention. It is a top view of a blower. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing of the casing for demonstrating the protrusion of the 1st side plate. FIG. 2 is a cross-sectional view taken along the line BB of FIG. It is sectional drawing of the main part of an impeller and a casing. It is a graph which shows the relationship between the ratio of the distance from the straight line extending in the axial direction through the other end of the rim in the axial direction to the center of the arc, and the distance from the center of rotation to the straight line, and specific noise. It is a graph which shows the relationship between the air volume and the specific noise. It is sectional drawing of the main part of the impeller and the casing which shows the other example of this invention. It is sectional drawing of the main part of the impeller and the casing which shows the other example of this invention. It is sectional drawing of the main part of the impeller and the casing which shows the other example of this invention. It is sectional drawing of the main part of the impeller and the casing which shows the other example of this invention. It is a figure explaining the relationship between the inner diameter dimension and the outer diameter dimension of the blade of an impeller.

1 to 8 show an embodiment of the present invention.

As shown in FIG. 1, the blower 1 of the present invention is a centrifugal blower, and is used, for example, as a blower means for an air conditioner for a vehicle.

As shown in FIG. 3, the blower 1 includes an impeller 10 formed in a cylindrical shape, an electric motor 20 for rotating the impeller 10, and a casing 30 in which the impeller 10 is housed. I have.

As shown in FIG. 3, the impellers 10 are arranged around the central axis of rotation at predetermined intervals in the circumferential direction, and each of the plurality of blades 11 extending in parallel with the central axis and the plurality of blades 11 It has a rim 12 as an annular portion connecting one end in the axial direction of the blade 11 and a substrate 13 connecting the other ends in the axial direction of a plurality of blades 11.

The plurality of blades 11 are arranged so as to extend from the inside to the outside in the radial direction. The radial outer side of each of the plurality of blades 11 is curved toward one of the circumferential directions with respect to the radial inner side.

The rim 12 is a cylindrical member in which one end of a plurality of blades 11 in the axial direction is connected. One end of the rim 12 extends from one end of the plurality of blades 11 in the axial direction to one end in the axial direction. One end side of the rim 12 extends in parallel with the axial direction, and the other end side in the axial direction extends obliquely outward in the radial direction via the bent portion 12a. The bent portion 12a is provided on one end side of the central portion in the axial direction of the rim 12. As shown in FIG. 6, the bent portion 12a bends the other end side in the axial direction with respect to one end side in the axial direction of the rim 12 extending in the axial direction at a predetermined angle θ within the range of 0 degrees to 90 degrees. .. The bent portion 12a connects the one end side and the other end side of the rim 12 in the axial direction with a curved surface.

The substrate 13 is a disk-shaped member in which the other ends of the plurality of blades 11 are connected to the outside in the radial direction. As shown in FIG. 3, an overhanging portion is formed on one end surface of the substrate 13 in the axial direction so as to gradually project from the radial inside of the outer peripheral portion to which each blade 11 is connected toward the central portion. Further, on the other end surface of the substrate 13 in the axial direction, a recess is formed which is gradually recessed from the radial inside of the outer peripheral portion to which each blade 11 is connected toward the central portion.

When the impeller 10 is rotated in one direction in the circumferential direction with the center in the radial direction as the rotation axis, air flows inward from one end side in the axial direction and air flows out radially outward from the gap of each blade 11. Let me.

As shown in FIG. 3, the electric motor 20 is arranged in the recess on the axial end surface of the substrate 13 on the axial end side of the impeller 10. In the electric motor 20, the rotating shaft 21 is connected to the radial center of the substrate 13, and the impeller 10 is rotated toward one of the circumferential directions in which the blade 11 is curved.

As shown in FIG. 3, the casing 30 has a first side plate 31 provided on one end side in the axial direction of the impeller 10, a second side plate 32 provided on the other end side in the axial direction of the impeller 10, and a first one. It has an outer peripheral plate 33 extending in the circumferential direction of the impeller 10 between the outer peripheral portions of the side plate 31 and the second side plate 32.

A circular suction port 34 for sucking air is provided in the casing 30 at a substantially central portion of the first side plate 31. Further, the edge portion of the suction port 34 in the first side plate 31 is used as an opening edge portion surrounding the axial end side of the rim 12 of the impeller 10 and the radial inner surface side and outer surface side of the axial end side of the rim 12. A bell mouth 31a is provided.

As shown in FIG. 6, the bell mouth 31a has an annular base portion 31a1 extending in a direction orthogonal to the axial direction, an annular outer wall portion 31a2 extending from the outer peripheral portion of the base portion 31a1 to the other end side in the axial direction, and an inner portion of the base portion 31a1. It has an annular inner wall portion 31a3 extending from the peripheral portion to the other end side in the axial direction. The base portion 31a1 and the outer wall portion 31a2 and the base portion 31a1 and the inner wall portion 31a3 are connected by curved surfaces.

The inner wall portion 31a3 extends from the base portion 31a1 toward the other end side in the axial direction over the circumferential direction. On the other end side of the inner peripheral surface of the inner wall portion 31a3 in the axial direction, a parallel wall surface 31a4 having a surface parallel to the rotation axis over the circumferential direction is formed. The axial dimension of the parallel wall surface 31a4 is approximately half of the dimension in which the inner wall portion 31a3 protrudes from the base portion 31a1 to the other end side in the axial direction.

As shown in FIG. 3, a motor support hole 32a for supporting the electric motor 20 in a penetrating state is provided in a substantially central portion of the second side plate 32.

As shown in FIG. 4, the outer peripheral plate 33 is a spiral in which the distance from the rotation axis of the impeller 10 gradually increases from a predetermined reference position away from the rotation axis of the impeller 10 toward the rotation direction of the impeller 10. A linear portion 33b extending linearly from the radially outer end of the spiral portion 33a, and a predetermined radius of curvature from the radially inner end of the spiral portion 33a in the direction opposite to the spiral portion 33a. It has a tongue portion 33c that is curved and extends, and an extension portion 33d that extends continuously from the tongue portion 33c with a straight line portion 33b at a distance.

Further, as shown in FIG. 1, the casing 30 is provided with a discharge port 35 for discharging the air sucked into the casing 30 through the suction port 34. The discharge port 35 is formed at the end of a portion surrounded by the first side plate 31, the second side plate 32, the straight portion 33b, and the extension portion 33d.

As shown in FIG. 4, a spiral ventilation passage 36 for circulating the air flowing in from the suction port 34 through the outer peripheral side of the impeller 10 in the rotation direction of the impeller 10 and a spiral ventilation passage 36 in the casing 30. A discharge ventilation passage 37 that communicates the terminal portion and the discharge port 35 is provided.

The spiral ventilation passage 36 is located between the first side plate 31 and the second side plate 32, and is located on the outer peripheral portion of the impeller 10 and the portion of the outer peripheral plate 33 on the spiral portion 33a and the straight portion 33b on the spiral portion 33a side. It is provided in between. As shown in FIG. 4, the spiral ventilation passage 36 gradually increases in the width dimension of the ventilation passage in the radial direction from the start end portion to the end portion.

The discharge ventilation passage 37 is provided between the first side plate 31 and the second side plate 32, and between the portion of the straight line portion 33b located on the discharge port 35 side and the extension portion 33d. As shown in FIG. 4, the discharge passage 37 gradually increases in the width dimension of the ventilation passage in the radial direction from the terminal portion of the spiral ventilation passage 36 toward the discharge port 35. Further, the discharge ventilation passage 37 is separated from the start end side of the spiral ventilation passage 36 by the tongue portion 33c.

As shown in FIG. 3, the portion of the first side plate 31 located on the radial outer side of the impeller 10 (the portion where the tongue portion 33c is located) protrudes toward the second side plate 32 side and the tongue portion 33c. A protrusion 31b extending in the circumferential direction toward the side opposite to the rotation direction of the impeller 10 is provided.

As shown in FIG. 4, the protrusion 31b has a protrusion angle θU in the rotation direction of the impeller 10 with reference to the position S of the radial inner end of the spiral portion 33a about the rotation axis of the impeller 10. It is provided between the protrusion start position located at and the tongue portion 33c. As shown in FIGS. 3 to 5, the height of the protrusion 31b gradually increases from the protrusion start position toward the tongue portion 33c until the maximum height is reached.

Further, on the outer peripheral side of the protrusion 31b, an inclined surface 31c whose height dimension gradually decreases toward the outside in the radial direction is provided in the extending direction of the protrusion 31b.

Here, as shown in FIG. 6, the bell mouth 31a continuously extends from the other end portion A of the parallel wall surface 31a4 in the axial direction toward the other end side in the axial direction along the parallel wall surface 31a4, and the axis of the parallel wall surface 31a4. The center C of the arc passing through the other end in the direction A and the other end in the axial direction B of the rim 12 is located radially outside the straight line D extending in the axial direction through the other end in the axial direction of the rim 12. ..

Further, the distance L from the straight line D extending in the axial direction passing through the other end of the rim 12 in the axial direction to the center C of the arc is 0 to 1.7 times the distance R from the rotation center E to the straight line D. It is set within the range (0 ≦ L / R ≦ 1.7).

The inner diameter R1 of the inner wall portion 31a3 of the bell mouth 31a is formed to have a size equal to or larger than the inner diameter R2 of the radial inner side of the blades 11 of the plurality of impellers 10 arranged in the circumferential direction.

The axial end portion A of the inner wall portion 31a3 of the bell mouth 31a is located between the axial end portion of the plurality of blades 11 and the axial end portion of the rim 12 in the axial direction. The distance between the other end portion A of the inner wall portion 31a3 in the axial direction and the one end portion in the axial direction of the blade 11 is 1 mm to 10 mm.

The protrusion 31b projects toward the other end in the axial direction from the other end A in the axial direction of the inner wall portion 31a3 of the bell mouth 31a to the other end B in the axial direction of the rim 12. The protrusion 31b is located in the vicinity of the tongue portion 33c and in the vicinity of the axially other end portion B of the rim 12.

The inclined surface 31c extends diagonally outward from the outer peripheral portion of the protrusion 31b in the extending direction of the protrusion 31b.

In the blower 1 configured as described above, when the electric motor 20 is driven to rotate the impeller 10 in one direction in the circumferential direction, the air outside the casing 30 passes through the suction port 34 provided in the first side plate 31. Is sucked into the casing 30. The air sucked into the casing 30 through the suction port 34 flows inward from the other end side in the axial direction of the impeller 10, and is radially discharged from the outer peripheral portion of the impeller 10. The air radially flowing out from the outer peripheral portion of the impeller 10 passes through the spiral ventilation passage 36 and the discharge ventilation passage 37 of the casing 30 and is discharged from the discharge port 35.

At this time, since the parallel wall surface 31a4 of the bell mouth 31a extends in the axial direction, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 is guided in the axial direction by the parallel wall surface 31a4.

Further, the axial dimension of the parallel wall surface 31a4 is approximately half of the dimension between the base portion 31a1 and the tip end portion of the inner wall portion 31a3. Therefore, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 is surely guided in the axial direction by the parallel wall surface 31a4.

Further, the inner diameter dimension R1 of the parallel wall surface 31a4 is formed to have a size equal to or larger than the inner diameter dimension R2 of the plurality of blades 11 arranged in the circumferential direction. Therefore, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 is guided inward in the radial direction of the blade of the impeller 10, but the significant increase in the flow velocity of the air passing through the suction port 34 is suppressed. Will be done.

The axial end portion A of the inner wall portion 31a3 is located between the axial end portion of the plurality of blades 11 and the axial end portion of the rim 12 in the axial direction. Further, the other end portion A in the axial direction of the inner wall portion 31a3 is located within a range of 1 mm to 10 mm from the one end portion in the axial direction of the rim 12 toward the other end portion in the axial direction in the axial direction. Therefore, the flow of air between the axial end portion of the rim 12 and the bell mouth 31a is suppressed.

Along the parallel wall surface 31a4, the bell mouth 31a continuously extends from the other end portion A in the parallel direction of the parallel wall surface 31a4 toward the other end side in the axial direction, and the other end portion A in the axial direction of the parallel wall surface 31a4 and the axis of the rim 12. The center C of the arc passing through the other end portion B in the direction is located radially outside the straight line D extending in the axial direction passing through the other end portion in the axial direction of the rim 12. Further, the distance L from the straight line D to the center C of the arc is set within the range of 0 to 1.7 times the distance R from the rotation center E to the straight line D. Therefore, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 flows along the inner peripheral surface of the inner wall portion 31a3 of the bell mouth 31a, and then the other end in the axial direction of the rim 12 of the impeller 10. It circulates along the inner peripheral surface on the side, passes through the gap between the blades 11, and flows into the spiral air passage 36 from the radial outside of the impeller 10.

The other end side in the axial direction of the rim 12 extends diagonally outward in the radial direction via the bent portion 12a. The bent portion 12a is arranged on one end side in the axial direction with respect to the central portion in the axial direction of the rim 12. Further, the bent portion 12a connects the one end side and the other end side of the rim 12 in the axial direction by a curved surface. Therefore, the air flowing along the inner peripheral surface of the rim 12 is guided outward in the radial direction without peeling.

The protrusion 31b projects toward the other end in the axial direction from the other end in the axial direction of the inner wall portion 31a3 of the bell mouth 31a to the other end B in the axial direction of the rim 12. The protrusion 31b is located in the vicinity of the tongue portion 33c and in the vicinity of the axially other end portion B of the rim 12. The inclined surface 31c extends diagonally outward from the outer peripheral portion of the protrusion 31b in the extending direction of the protrusion 31b. Therefore, the air flowing from one end side in the axial direction of the impeller 10 to the outside in the radial direction flows into the spiral ventilation passage 36 along the protrusion 31b and the inclined surface 31c without disturbing the flow.

Here, the ratio (L /) of the distance L from the straight line D extending in the axial direction passing through the other end portion B in the axial direction of the rim 12 to the center C of the arc and the distance R from the rotation center E of the impeller 10 to the straight line D. Regarding R), the tests conducted to obtain appropriate values and the test results will be described.

FIG. 7 measures the magnitude of noise when the ratio (L / R) of the distance L from the straight line D to the center C of the arc and the distance R from the rotation center E of the impeller 10 to the straight line D is changed. It is a graph which shows the result of this. As shown in FIG. 7, the ratio (L / R) of the ratio (L / R) of the distance L from the straight line D to the center C of the arc and the distance R from the rotation center E of the impeller 10 to the straight line D is 0 to the specific noise value. If it is in the range of 1.7, it will be in a low state. The ratio (L / R) of the distance L from the straight line D to the center C of the arc and the distance R from the rotation center E of the impeller 10 to the straight line D is lower in the range of 0.5 to 1.3. Become.

FIG. 8 shows a blower 1 in which the ratio (L / R) of the distance L from the straight line D to the center C of the arc and the distance R from the rotation center E to the straight line D is set in the range of 0 to 1.7. It is a graph which shows the test result which measured the magnitude of the noise when the air volume was changed in the conventional blower which did not have the structure of the invention. The specific noise value of the blower 1 is smaller than the specific noise value of the conventional blower in the range of the air volume used as the air conditioner for vehicles.

As described above, according to the blower of the present embodiment, the bell mouth 31a continuously extends from the other end portion A in the axial direction of the parallel wall surface 31a4 toward the other end side in the axial direction, and the other end portion in the axial direction of the parallel wall surface 31a4. The center C of the arc passing through the axial end portion B of the portion A and the axial end portion B of the rim 12 is located radially outside the straight line D extending in the axial direction passing through the axial end portion B of the rim 12, and is located from the straight line D. The distance L to the center C of the arc is in the range of 0 to 1.7 times the distance R from the rotation center E to the straight line D.

As a result, it is possible to suppress the separation of the air flow flowing along the inner peripheral surface of the inner wall portion 31a3 of the bell mouth 31a and the inner peripheral surface of the rim 12, so that the sound at one end side in the axial direction of the impeller 10 can be suppressed. It is possible to suppress the occurrence and improve the quietness.

Further, a parallel wall surface 31a4 extending in the axial direction is formed on the other end side of the inner peripheral surface of the inner wall portion 31a3 in the axial direction.
Further, the axial dimension of the parallel wall surface 31a4 is approximately one half of the dimension between the base portion 31a1 and the tip portion of the inner wall portion 31a3.

As a result, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 can be guided in the axial direction along the parallel wall surface 31a4, so that the turbulence of the air flow on the outer peripheral side of the suction port 34 is suppressed. It becomes possible to do.

Further, the other end portion of the rim 12 in the axial direction extends outward in the radial direction via the bent portion 12a.
Further, the bent portion 12a has the other end side in the axial direction of the rim 12 directed outward in the radial direction in a range of 0 to 90 degrees with respect to the axial direction.
Further, the bent portion 12a is connected between one end side and the other end side in the axial direction by a curved surface.

As a result, the air circulated in the axial direction from the outer peripheral side of the suction port 34 is circulated along the inner peripheral surface of the rim 12, so that the direction can be changed to the outside in the radial direction. It is possible to suppress the turbulence of the air flow on the inner peripheral surface side.

Further, the bent portion 12a is provided on one end side in the axial direction with respect to the central portion in the axial direction of the rim 12.

As a result, it is possible to set a large distance extending outward in the radial direction on the inner peripheral surface of the rim 12, so that it is possible to reliably guide the air flowing in from the outer peripheral side of the suction port 34 outward in the radial direction. Become.

Further, the inner diameter dimension R1 of the parallel wall surface 31a4 of the bell mouth 31a is larger than the inner diameter dimension R2 of the plurality of blades 11 arranged in the circumferential direction.

As a result, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 can be guided in the radial direction of the blade 11 of the impeller 10, and the flow velocity of the air passing through the suction port 34 is remarkable. It is possible to suppress the rise and improve the quietness.

Further, the tip portion of the inner wall portion 31a3 is located between the axial end portion of the blade 11 and the axial end portion of the rim 12 in the axial direction.
Further, the tip portion of the inner wall portion 31a3 is located within a range of 1 mm to 10 mm from one end portion in the axial direction of the rim 12 in the axial direction.

As a result, it is possible to suppress the flow of air between one end of the rim 12 in the axial direction and the bell mouth 31a, so that it is possible to prevent the generation of sound due to the flow of air between the rim 12 and the bell mouth 31a. It becomes possible.

The protrusion 31b is located between the axially other end of the inner wall 31a3 and the axially other end B of the rim 12 in the axial direction.
Further, on the outer peripheral side of the protrusion 31b, an inclined surface 31c whose dimension gradually protrudes outward in the radial direction is provided in the extending direction of the protrusion 31b.

As a result, it is possible to suppress the turbulence of the air flow flowing out from the outer peripheral side of the impeller 10 at one end side in the axial direction in the casing 30, and it is possible to improve the quietness.

9 and 10 show other examples of the bell mouth 31a of the present invention, respectively.

A curved wall surface 31a5 whose radial dimension gradually increases toward the other end in the axial direction is formed on the other end side in the axial direction of the inner peripheral surface of the inner wall portion 31a3 of the bell mouth 31a shown in FIGS. 9 and 10. There is.

Further, the inner diameter dimension R3 of the other end in the axial direction of the curved wall surface 31a5 is within the range of 0.95 to 1.05 times the inner diameter dimension R4 of the plurality of blades 11 arranged in the circumferential direction. Further, the inner diameter dimension R5 of one end portion in the axial direction of the curved wall surface 31a5 is within the range of 0.94 to 1 times the inner diameter dimension R3 of the other end portion in the axial direction of the curved wall surface 31a5.

The outer peripheral surface 31a6 of the inner wall portion 31a3 is parallel to the axis of rotation over the circumferential direction.

The inner wall portion 31a3 is formed to have a smaller thickness dimension toward the other end portion (tip portion) in the axial direction over the circumferential direction. In particular, the other end portion (tip portion) in the axial direction of the inner wall portion 31a3 shown in FIG. 10 is formed so that the cross section forms an acute angle from the curved wall surface 31a5 and the outer peripheral surface 31a6 over the circumferential direction.

In the blower configured as described above, when the electric motor 20 is driven to rotate the impeller 10 in one circumferential direction, the air sucked into the casing 30 through the suction port 34 as in the above embodiment. Is discharged from the discharge port 35 of the casing 30.

At this time, on the other end side of the inner peripheral surface of the inner wall portion 31a3 in the axial direction, a curved wall surface 31a5 whose radial dimension gradually increases toward the other end side in the axial direction is formed. Further, the inner diameter dimension R3 of the other end in the axial direction of the curved wall surface 31a5 is within the range of 0.95 to 1.05 times the inner diameter dimension R4 of the plurality of blades 11 arranged in the circumferential direction. Further, the inner diameter dimension R5 of the axial end portion of the curved wall surface 31a5 is within the range of 0.94 to 1 times the inner diameter dimension R3 of the axial end portion of the curved wall surface 31a5. Therefore, the air that has flowed into the casing 30 through the outer peripheral side of the suction port 34 circulates along the curved wall surface 31a5, and is guided so that the flow direction changes from the axial direction to the radial outer direction.

As described above, according to the blower of the present embodiment, it is possible to suppress the generation of sound on one end side in the axial direction of the impeller 10 as in the above embodiment, so that it is possible to improve the quietness. It becomes.

Further, on the tip end side of the inner peripheral surface of the inner wall portion 31a3, a curved wall surface 31a5 whose radial dimension increases toward the tip portion in the circumferential direction is formed.
Further, the inner diameter dimension R3 of the other end in the axial direction of the curved wall surface 31a5 is within the range of 0.95 to 1.05 times the inner diameter dimension R4 of the plurality of blades 11 arranged in the circumferential direction.
Further, the inner diameter dimension R5 of one end portion in the axial direction of the curved wall surface 31a5 is within the range of 0.94 to 1 times the inner diameter dimension R3 of the other end portion in the axial direction of the curved wall surface 31a5.

As a result, the air flowing into the casing 30 through the outer peripheral side of the suction port 34 is guided by the curved wall surface 31a5 so that the flow direction changes from the axial direction to the radial outer direction. Therefore, the air flowing along the curved wall surface 31a5 easily flows along the inner peripheral surface of the rim 12, and it is possible to suppress the separation of the air on the inner peripheral surface of the rim 12.

The outer peripheral surface 31a6 of the inner wall portion 31a3 extends parallel to the rotation axis in the circumferential direction.

As a result, even when the curved wall surface 31a5 is formed on the inner peripheral surface of the inner wall portion 31a3, the bell mouth 31a can be formed by the molds paired in the axial direction.

The inner wall portion 31a3 is formed to have a smaller thickness dimension toward the other end in the axial direction over the circumferential direction.

As a result, the air entering the casing 30 through the outer peripheral side of the suction port 34 flows at the end surface of the other end in the axial direction of the inner wall portion 31a3 when passing through the other end in the axial direction of the inner wall portion 31a3. It is possible to suppress the disturbed state, and it is possible to suppress the generation of sound.

FIG. 11 shows another example of the protrusion 31b.

The protrusion 31b shown in FIG. 11 has an inner peripheral surface that extends continuously from the outer wall portion 31a2 of the bell mouth 31a and is formed so as to follow the shape of the outer peripheral surface of the rim 12.

In the blower configured as described above, the distance between the inner peripheral surface of the protrusion 31b and the outer peripheral surface of the rim 12 becomes uniform in the axial direction, and the space between the inner peripheral surface of the protrusion 31b and the outer peripheral surface of the rim 12 is set. The turbulence of the flowing air is suppressed.

As described above, according to the blower of the present embodiment, it is possible to suppress the generation of sound on one end side in the axial direction of the impeller 10 as in the above embodiment, so that it is possible to improve the quietness. It becomes.

Further, the inner peripheral surface of the protrusion 31b is formed along the shape of the outer peripheral surface of the rim 12.

As a result, the distance between the inner peripheral surface of the protrusion 31b and the outer peripheral surface of the rim 12 becomes uniform in the axial direction, so that the air turbulence flowing between the inner peripheral surface of the protrusion 31b and the outer peripheral surface of the rim 12 is disturbed. It is suppressed, and it becomes possible to suppress the generation of sound.

In addition to the means for sending the air conditioner for vehicles, the embodiment can also be applied to the means for blowing air such as an air conditioner in a building or a ventilation device.

Further, in the above-described embodiment, the one in which one end side in the axial direction of the rim 12 is formed in a tubular shape extending in the axial direction and the other end side in the axial direction extends outward in the radial direction is shown, but the present invention is limited to this. is not it. The rim 12 may be formed so that the other end side in the axial direction extends radially outward through the bent portion 12a. For example, as shown in FIG. 12, one end side and the other end side in the axial direction of the rim 12 are respectively formed. Even if the shape is formed so as to extend radially outward through the bent portion 12a and the axial intermediate portion is convex inward in the radial direction, the same effect as that of the present invention can be obtained.

Further, in the above embodiment, the inner diameter dimension R6 of the plurality of blades 11 arranged in the circumferential direction is set in the range of 0.65 to 0.8 times the outer diameter dimension R7 as shown in FIG. It is preferable (0.65 ≦ R6 / R7 ≦ 0.8). In the impeller 10 having the blade 11 set within this range, the air flowing into the radial center portion appropriately flows between the blade 11 and the blade 11 from the inner peripheral side to the outer peripheral side. It is rectified and flows out from the outer peripheral portion of the impeller 10, and disturbance that causes noise and an increase in distribution resistance is suppressed, and it is possible to improve quietness and ventilation efficiency.

1 ... blower, 10 ... impeller, 11 ... wing, 12 ... rim, 12a ... bent part, 13 ... substrate, 30 ... casing, 31 ... first side plate, 31a ... bell mouth, 31a3 ... inner wall part, 31a4 ... parallel wall surface , 31a5 ... Curved wall surface, 31a6 ... Outer peripheral surface, 31b ... Protrusion, 31c ... Inclined surface, 34 ... Suction port.

Claims (18)

A plurality of blades extending parallel to the rotation axis at intervals around the rotation axis, an annular portion connecting the axial end portions of the plurality of blades, and a substrate connecting the axial end portions of the plurality of blades. With an impeller with,
A casing is provided with a circular suction port for sucking air on one end side in the axial direction, and a spiral ventilation path is formed on the radial outer side of the impeller housed inside.
The opening edge of the suction port in the casing has an inner wall portion whose end extends toward the other end in the axial direction.
The center of the arc that extends continuously from the inner peripheral surface of the tip of the inner wall toward the other end in the axial direction and passes through the tip of the inner peripheral surface of the inner wall and the other end in the axial direction of the annular portion is It is located radially outside the straight line extending axially through the other end of the annular portion in the axial direction.
The distance from the axially extending straight line passing through the other end of the annular portion to the center of the arc is relative to the distance from the center of the rotating shaft to the axially extending straight line passing through the other end of the annular portion in the axial direction. , Blowers in the range of 0.5 to 1.7 times. The blower according to claim 1, wherein a parallel wall surface having a surface parallel to the axis of rotation is formed on the tip end side of the inner peripheral surface of the inner wall portion. The blower according to claim 2, wherein the axial dimension of the parallel wall surface is one half of the axial dimension of the inner wall portion. The blower according to claim 1, wherein a curved wall surface whose radial dimension increases toward the tip portion in the circumferential direction is formed on the tip end side of the inner peripheral surface of the inner wall portion. The inner diameter dimension of the other end in the axial direction of the curved wall surface is in the range of 0.95 to 1.05 times the inner diameter dimension of the plurality of blades arranged in the circumferential direction.
The blower according to claim 4, wherein the inner diameter dimension of one end portion in the axial direction of the curved wall surface is within the range of 0.94 to 1 times the inner diameter dimension of the other end portion in the axial direction of the curved wall surface. The blower according to claim 4 or 5, wherein the outer peripheral surface of the inner wall portion extends in parallel with the axis of rotation in the circumferential direction. The blower according to any one of claims 4 to 6, wherein the inner wall portion is formed so as to have a smaller thickness dimension toward the other end portion in the axial direction in the circumferential direction. The blower according to any one of claims 1 to 7, wherein the annular portion has the other end in the axial direction extending outward in the radial direction via the bent portion. The blower according to claim 8, wherein the bent portion has the other end side in the axial direction of the annular portion directed outward in the radial direction in a range of 0 to 90 degrees with respect to the axial direction. The blower according to claim 8 or 9, wherein the bent portion is provided on one end side in the axial direction with respect to the central portion in the axial direction of the annular portion. The blower according to any one of claims 8 to 10, wherein the bent portion is connected between one end side and the other end side in the axial direction by a curved surface. The blower according to any one of claims 8 to 11, wherein the annular portion is formed in a cylindrical shape in which an intermediate portion in the axial direction is convex toward the rotation axis. The blower according to any one of claims 1 to 12, wherein the inner diameter of the inner wall portion is larger than the radial inner diameter of a plurality of blades arranged in the circumferential direction. The blower according to any one of claims 1 to 13, wherein the tip portion of the inner wall portion is located between one end in the axial direction of the blade and one end in the axial direction of the annular portion in the axial direction. The blower according to claim 14, wherein the tip portion of the inner wall portion is located within a range of 1 mm to 10 mm from one end of the annular portion in the axial direction in the axial direction. The casing has a discharge air passage extending from the end of the spiral air passage toward the air discharge port, a tongue portion separating the start end of the spiral air passage and the discharge air passage, and a spiral on the radial outside of the opening edge. It has a protrusion that gradually increases in the dimension of protrusion toward the other end in the axial direction from a predetermined position toward the end of the ventilation path toward the tongue.
The blower according to any one of claims 1 to 15, wherein the protrusion is located between the tip end portion of the inner wall portion and the axial end portion of the annular portion in the axial direction. The blower according to claim 16, wherein an inclined surface having a dimension that gradually protrudes outward in the radial direction is provided on the outer peripheral side of the protrusion in the extending direction of the protrusion. The blower according to claim 16 or 17, wherein the shape of the inner peripheral surface of the protrusion is formed along the shape of the outer peripheral surface of the annular portion.

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