JP5195276B2 - Centrifugal blower and air conditioner using the same - Google Patents

Description

  The present invention relates to a centrifugal blower, and more particularly to a centrifugal blower suitable for application to a ceiling-embedded air conditioner that requires flattening, and an air conditioner configured with the centrifugal blower.

  In recent years, a centrifugal blower applied to an air conditioner, particularly a ceiling-embedded air conditioner, has a strong demand for flattening, and as a response to this, as in the centrifugal blower shown in FIG. Have been proposed (see FIG. 10 of Patent Document 1 and FIG. 7 of Patent Document 2).

  The centrifugal blower includes a plurality of blades 56 arranged upright at predetermined intervals in the circumferential direction on the outer peripheral portion of the main plate 54, and a blade configured by attaching a shroud 55 on the end surface of each blade 56 on the side opposite to the main plate. The vehicle 53 is arranged with its main plate 54 facing the flat casing rear plate 51 in close proximity, and the shroud 55 facing the air inlet 61 formed by the bell mouth 52a of the casing front plate 52. The air sucked from the air inlet 61 is blown out from an air outlet 62 opened on the outer peripheral surface of the impeller 53 as shown in a main flow indicated by a flow line A1 in the drawing.

  Thus, in the centrifugal blower having a structure in which the main plate 54 extends to the outer periphery of the blade 56, the boundary layer develops on the surface of the main plate 54 by the main flow A1 flowing along the main plate 54. The flow path width of the main flow A1 is reduced, and the air blowing performance is reduced. Such a problem is more conspicuous in a centrifugal blower having a structure in which the width dimension of the blades 56 is reduced with flattening.

  Against this background, for example, as shown in FIG. 23, the base end side end surface (main plate side end surface) 56a of the blade 56 is opened to eliminate the influence of the boundary layer on the surface of the main plate 54, and the blade 56 There has been proposed a centrifugal blower including an impeller 53 that is reinforced by providing a reinforcing ring member 64 on the outer peripheral portion on the base end side (see FIG. 3 of Patent Document 1).

JP 2004-308442 A JP 2006-322442 A

  However, in the centrifugal blower having the configuration shown in FIG. 23, although the influence of the boundary layer on the surface of the main plate 54 can be eliminated, the base end side end face of the blade 56 is opened, so that it is blown out from the air outlet 62. A part of the main flow A1 generates a backflow A2 that circulates from the outside of the ring member 64 to the casing rear plate 51 side due to the Coanda effect on the surface of the ring member 63.

  In this case, since the end face on the base end side of the blade 56 is wide open, the backflow A2 flows deeply along the casing rear plate 51 toward the center of the impeller 53 and opens to the main plate 54 side. From the wide end surface 56a of the blade 56 to the inner surface 54a side of the main plate 54, which interferes with the main flow A1 flowing between the blades and disturbs the flow. The blowing noise increases, and the profit that eliminates the influence of the boundary layer on the surface of the main plate 54 is reduced.

  Therefore, the present invention has an object to provide a centrifugal blower capable of improving the noise characteristics while maintaining the effect of suppressing the boundary layer due to the backflow, and an air conditioner equipped with the centrifugal blower. It is.

  In the present invention, the following configuration is adopted as specific means for solving the above-described problems.

(A) 1st invention In 1st invention of this application, it arranges in parallel in the state which maintained the predetermined space | interval in the circumferential direction, and opened the main plate side end surface on the outer periphery of the main plate rotated and this main plate. A centrifugal blower comprising a plurality of blades, a ring member provided on the outer peripheral surface of the main plate side end of the plurality of blades, and a casing rear plate provided on the back side of the main plate. The casing rear plate is provided with a circular recess that opens to the main plate side and wraps around the outer periphery of the ring member.

(B) Second invention In the second invention of the present application, a large number of blades are arranged upright at predetermined intervals in the circumferential direction with respect to the main plate to be rotationally driven, with the base end side end surface thereof being opened. In addition, in the centrifugal blower provided with the impeller having an annular ring member provided on the outer peripheral surface of the base end side of the blade, a casing rear plate is disposed facing the back surface of the main plate, and the casing rear plate Is provided with a circular recess that opens to the main plate side and encloses the outer peripheral portion of the annular ring member, and a side extension that extends radially outward continuously from the outer peripheral edge of the open side of the circular recess. It is characterized by being.

(C) Third invention In the third invention of the present application, in the centrifugal blower according to the first or second invention, the circular recess is a circular recess provided in a thickness of the casing rear plate. It is characterized by being formed by a concave groove.

(D) Fourth invention In the fourth invention of the present application, in the centrifugal blower according to the first invention, the circular recess is an annular ring erected in the main plate side direction from the main plate side inner surface of the casing rear plate. It is characterized by being formed of a cylindrical wall.

(E) Fifth Invention In the fifth invention of the present application, in the centrifugal blower according to the second or third invention, the surface of the side extension portion of the casing rear plate and the inner side surface of the main plate are the blades. It is set so that it may be located in the substantially same position in the axial direction of a vehicle.

(F) Sixth Invention In the sixth invention of the present application, in the centrifugal blower according to the first, second, third, fourth, or fifth invention, the impeller is disposed on an end surface on the tip side of the blade. It is the structure provided with the shroud.

(G) Seventh Invention In the seventh invention of the present application, in the centrifugal blower according to the first, second, third, fourth, or fifth invention, the impeller is provided on a front end side end surface of the blade. The configuration is characterized in that no shroud is provided.

(H) Eighth Invention In the eighth invention of the present application, a heat exchanger and a blower are provided in a ventilation path extending from the air inlet to the air outlet in a casing having an air inlet and an air outlet. It is an air conditioner that is arranged at the front and back, and is constructed by adopting the centrifugal blower according to the first, second, third, fourth, fifth, sixth or seventh invention as a blower. It is characterized by being.

  In the first to eighth inventions of the present application, the following effects can be obtained.

(A) 1st invention According to the centrifugal blower which concerns on 1st invention of this application, a predetermined space | interval is maintained in the circumferential direction on the main plate and the outer periphery of this main plate, and the main plate side end surface is opened. A plurality of blades arranged side by side, a ring member provided on the outer peripheral surface of the main plate side end of the plurality of blades, and a casing rear plate provided on the back side of the main plate The casing rear plate is provided with a circular recess that opens to the main plate side and wraps around the outer periphery of the ring member.

  Therefore, due to the Coanda effect on the outer surface of the ring member, the backflow flowing around to the back side of the ring member and re-entering between the blades from the open end side of the blade is wrapped around the outside of the ring member. The inner wall surface of the circular recess receives a deflection action along the outer surface shape of the ring member. As a result, due to the synergistic action of the Coanda effect and the deflection action, the back flow flows to the impeller. The flow is circulated within a narrow range around the ring member without greatly flowing toward the center, and the reverse flow is prevented from interfering with the main flow and disturbing the flow as much as possible.

  Further, when the outer peripheral side of the ring member is wrapped by the circular concave portion of the rear plate of the casing, the passage area of the air flowing into the outer peripheral side of the ring member is reduced as compared with the case where it is not so Accordingly, the flow rate of the reverse flow itself is reduced, and the phenomenon in which the reverse flow interferes with the main flow and disturbs the flow is suppressed as much as possible.

  As a synergistic effect of these two actions, it is possible to provide a centrifugal blower that is effectively reduced in noise due to the above-described disturbance of the main flow and is as quiet as possible.

(B) 2nd invention According to the centrifugal blower which concerns on 2nd invention of this application, many blade | wings were made to open | release the base end side end surface at the predetermined spacing in the circumferential direction with respect to the main plate rotationally driven. In a centrifugal blower provided with an impeller comprising an annular ring member provided on the outer peripheral surface on the base end side of the blade, a casing rear plate is disposed opposite the back surface of the main plate. The casing rear plate has a circular recess that opens to the main plate side and wraps around the outer peripheral portion of the annular ring member, and extends radially outward from the outer peripheral edge of the open side of the circular recess. A side extension is provided.

  Therefore, due to the Coanda effect on the outer surface of the ring member, the backflow flowing around to the back side of the ring member and re-entering between the blades from the open end side of the blade is wrapped around the outside of the ring member. The inner wall surface of the circular recess receives a deflection action along the outer surface shape of the ring member. As a result, due to the synergistic action of the Coanda effect and the deflection action, the back flow flows to the impeller. The flow is circulated within a narrow range around the ring member without greatly flowing toward the center, and the reverse flow is prevented from interfering with the main flow and disturbing the flow as much as possible.

  Further, when the outer peripheral side of the ring member is wrapped by the circular concave portion of the rear plate of the casing, the passage area of the air flowing into the outer peripheral side of the ring member is reduced as compared with the case where it is not so Accordingly, the flow rate of the reverse flow itself is reduced, and the phenomenon in which the reverse flow interferes with the main flow and disturbs the flow is suppressed as much as possible.

  As a synergistic effect of these two actions, it is possible to provide a centrifugal blower that is effectively reduced in noise due to the above-described disturbance of the main flow and is as quiet as possible.

(C) 3rd invention According to the centrifugal blower which concerns on 3rd invention of this application, in the centrifugal blower which concerns on the said 1st or 2nd invention, the said circular recessed part is dented within the plate | board thickness of the said casing rear plate. It is formed by the provided circular groove part.

  Therefore, the casing that wraps around the outside of the ring member is caused by the Coanda effect on the outer surface of the ring member. Due to the inner peripheral wall surface of the circular concave portion formed by a circular concave groove provided recessed in the thickness of the rear plate, a deflection action is applied along the outer surface shape of the ring member, and the Coanda effect and the deflection action By the synergistic action of the above, the flow does not flow greatly to the center side of the impeller, but becomes a circulating flow that circulates within a narrow range around the ring member, and the countercurrent flow interferes with the main flow and disturbs the flow. Is suppressed as much as possible.

  Further, when the outer peripheral side of the ring member is wrapped by the circular recess provided in the thickness of the rear plate of the casing, it flows into the outer peripheral side of the ring member as compared with the case where it is not so. Thus, the flow area of the backflow is reduced, and the phenomenon that the backflow interferes with the main flow and disturbs the flow is suppressed as much as possible.

  As a synergistic effect of these two actions, it is possible to provide a centrifugal blower that is effectively reduced in noise due to the above-described disturbance of the main flow and is as quiet as possible.

(D) 4th invention According to the centrifugal blower which concerns on 4th invention of this application, in the centrifugal blower which concerns on the said 1st invention, the said circular recessed part is the main plate side direction from the main plate side inner surface of the said casing rear plate. It is formed by the cyclic | annular cylindrical wall erected by.

  Therefore, due to the Coanda effect on the outer surface of the ring member, the backflow flowing around the back surface side of the ring member and re-entering between the blades from the open end side of the blade is caused after the casing that wraps the outside of the ring member. Deflection along the outer surface shape of the ring member by the inner peripheral wall surface of a circular recess formed by an annular cylindrical wall of a predetermined height standing on the inner surface side of the main plate of the plate. Due to the synergistic action of the Coanda effect and the deflection action, the flow becomes a circulating flow that circulates within a narrow range around the ring member without flowing greatly to the center side of the impeller, and the backflow flow is Interfering with the main flow and disturbing the flow is suppressed as much as possible.

  Further, as described above, when the outer peripheral side of the ring member is wrapped by the circular recess formed by the annular cylindrical wall erected from the main plate side inner surface of the casing rear plate in the main plate side direction, Compared with those not, the passage area of the air flowing into the outer peripheral side of the ring member is reduced, the flow rate of the backflow itself is reduced, and the phenomenon that the backflow flow interferes with the main flow flow and disturbs the flow. Suppressed as much as possible.

  As a synergistic effect of these two actions, it is possible to provide a centrifugal blower that is effectively reduced in noise due to the above-described disturbance of the main flow and is as quiet as possible.

  Further, in this way, when the circular recess is formed by the annular cylindrical wall erected in the main plate side direction from the main plate side inner surface of the casing rear plate, there is no need to increase the plate thickness of the casing rear plate. Therefore, the passage sectional area of the air outlet can be increased by that amount, and the performance in a large air volume region can be improved.

(E) Fifth Invention According to the centrifugal blower according to the fifth invention of the present application, in the centrifugal blower of the second or third invention, the surface of the side extension portion of the casing rear plate and the inside of the main plate The side surfaces are set so as to be located at substantially the same position in the axial direction of the impeller.

  Therefore, according to such a configuration, in addition to the effect described in (b) the second invention, the following specific effect can be obtained.

That is, in the centrifugal blower of the present invention, the surface of the side extension portion of the casing rear plate and the inner surface of the main plate are set so as to be located at substantially the same position in the axial direction of the impeller. The flow state of the backflow that circulates around the ring member through the facing gap between the both becomes smoother and more stable, and the noise suppressing effect is further promoted.

(F) Sixth Invention According to the centrifugal blower according to the sixth invention of the present application, in the centrifugal blower according to the first, second, third, fourth, or fifth invention, the impeller includes the above A shroud is provided on the end face side end face of the blade.

  Therefore, according to such a configuration, (a) the first invention, (b) the second invention, (c) the third invention, (d) the fourth invention, or (e) the fifth invention. In addition to the effects described above, the following specific effects can be obtained.

  That is, in the centrifugal blower of the present invention, even if the impeller has a configuration in which a shroud is provided on the end surface of the blade, the backflow that circulates around the ring member without being affected by the presence of the shroud. The noise reduction effect based on the flow is obtained, and the noise reduction is also achieved in the centrifugal blower including the impeller with the shroud.

(G) Seventh Invention According to the centrifugal blower according to the seventh invention of the present application, in the centrifugal blower according to the first, second, third, fourth or fifth invention, the impeller includes the above A shroud is not provided on the end face of the blade.

  Therefore, according to such a configuration, (a) the first invention, (b) the second invention, (c) the third invention, (d) the fourth invention, or (e) the fifth invention. In addition to the effects described above, the following specific effects can be obtained.

  That is, in the centrifugal blower of the present invention, the impeller circulates around the ring member without being affected by the absence of the shroud even if the shroud is not provided with the shroud on the tip end surface of the blade. The noise reduction effect based on the backflow flow is obtained, and the noise reduction is also achieved in the centrifugal blower provided with the shroud impeller.

(H) Eighth Invention In the air conditioner according to the eighth invention of the present application, heat is supplied to the ventilation path extending from the air inlet to the air outlet in a casing having an air inlet and an air outlet. An air conditioner in which an exchanger and a blower are arranged before and after the centrifugal blower according to the first, second, third, fourth, fifth, sixth, or seventh invention as a blower. Is adopted.

  Therefore, the characteristics of each centrifugal blower, that is, the low noise characteristics described above are utilized, and it is possible to provide an air conditioner that is low in operating noise and excellent in quietness.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

<I: First Embodiment>
First, FIG. 1 shows a centrifugal blower 1 according to a first embodiment of the present invention. The centrifugal blower 1 is configured by accommodating an impeller 2 having the following configuration between a casing front plate 3 and a casing rear plate 4 which are opposed to each other with a predetermined interval.

  As shown in FIGS. 1 and 2, the impeller 2 includes a main plate 11, a shroud 12, a large number of blades 13, and a ring member 16. In this embodiment, as an example, these members are integrally formed by resin molding.

  The main plate 11 is configured to bulge a central portion of a disc body having a predetermined diameter toward one side surface and to provide a boss 15 on the bulged portion. The vacant portion on the back side of the bulging portion is a space for arranging the motor 14 attached to the casing rear plate 4 to be described later, and a boss 15 is provided at the central portion thereof.

  A large number of blades 13 are connected to the outer peripheral surface 11b of the inner peripheral side edge 13a on the outer peripheral surface 11b of the main plate 11 and from the inner peripheral side edge 13a to the outer peripheral edge. It is provided in a state inclined toward the rear side in the rotation direction toward the portion 13b.

  In this case, the portions closer to the base end portion 13c of the outer peripheral edge portion 13b of each blade 13 are sequentially connected in the circumferential direction by a ring member 16 having a substantially rectangular cross-sectional shape. In addition, an annular shroud 12 is integrally formed at a portion near the outer peripheral edge portion 13b of the tip side end face 13f of each blade 13. Each of the blades 13 is reinforced by the ring member 16 and the shroud 12, and high strength performance is ensured while having a unique configuration in which the proximal end surface 13 e of the blade 13 is opened.

  In addition, as shown in FIG. 3, the formation position with respect to the main plate 11 is set so that the base end side end surface 13e of the blade 13 is flush with the outer side surface 11c of the main plate 11. In addition, the ring member 16 is formed at a position where the one surface 16a is substantially flush with the proximal end surface 13e of the blade 13 and the other surface 16b is next. The height dimension of the apparatus is set so as to be substantially flush with the surface of the side extension 41 of the casing rear plate 4 to be described.

  As shown in FIG. 1, the casing front plate 3 is made of a plate material, and a bell mouth 5 is formed at the center thereof, and an air suction port 6 is constituted by the bell mouth 5. On the other hand, as shown in FIGS. 1 to 3, the casing rear plate 4 is configured by a flat plate, and has a central portion that opens on one side surface (the main plate 11 side) and opens the other side (outward). A circular concave portion 42 is provided which is recessed toward the side surface side and includes a circular peripheral wall surface 42a and a bottom wall surface 42b located inside the circular peripheral wall surface 42a. And the outer side part from this circular recessed part 42 is a side extension part (in the direction of an air blower outlet) extended in the planar direction outward continuously from the opening edge of this circular recessed part 42, ie, the edge part of the said surrounding wall surface 42a. The outlet passage wall surface portion) 41. These casing front plate 3 and casing rear plate 4 constitute a casing.

  The centrifugal blower 1 is obtained by assembling the impeller 2 in a casing composed of the casing front plate 3 and the casing rear plate 4. That is, the impeller 2 is attached to the casing rear plate 4 side by fixing the motor 14 attached to the boss 15 of the main plate 11 to the casing rear plate 4. The casing front plate 3 is fixed to the casing rear plate 4 in a state where the bell mouth 5 portion is fitted on the inner peripheral side of the shroud 12 of the impeller 2 (not shown).

  In the assembled state of the impeller 2 on the casing rear plate 4 side, the outer peripheral portion of the main plate 11 of the impeller 2 is placed in the circular recess 42 of the casing rear plate 4 as shown in FIG. The outer peripheral portion of each blade 13 on the base end portion 13 c side and the outer peripheral side of the ring member 16 attached thereto are wrapped by the peripheral wall surface 42 a of the circular recess 42. In this case, as described above, the inner side surface 11a of the main plate 11 and the other side surface 16b of the ring member 16 are substantially flush with the surface of the side extending portion 41 on the casing rear plate 4 side. It is.

  And between the inner surface of the circular recess 42 of the casing rear plate 4 and the ring member 16 and the main plate 11 on the impeller 2 side, from the surface of the side extension 41, from the entire circumference of the circular recess 42. After entering toward the bottom wall surface 42b, a gap 45 is formed that expands along the bottom wall surface 42b. The gap 45 communicates with the air outlet 7 through the blades because the base end side end surface 13e of the blade 13 is open to the main plate 11 side.

  In the centrifugal blower 1 configured as described above, when the impeller 2 is rotationally driven by the motor 14, the air sucked from the air suction port 6 is given energy by the blades 13, As mainstream flow A1, it blows off from the air blower outlet 7 of the outer peripheral side of the said impeller 2 toward the perimeter.

  Here, of the main flow A1, a part of the flow flowing on the main plate 11 side circulates from the outer side of the ring member 16 to the casing rear plate 4 side due to the Coanda effect by the surface of the ring member 16 and backflow. In this case, for example, as in the conventional structure shown in FIG. 10, if the casing rear plate is a simple flat plate, the backflow A2 is flown along the casing rear plate. Widely flows toward the center side and re-flows into the inner side surface 11a side of the main plate 11 from a wide range of the base end side end surface 13e of the blade 13 opened to the main plate 11 side, and this flows between the blades. As described above, the mainstream flow A1 interferes with the flow and disturbs the flow, resulting in an increase in blowing noise.

  However, in the centrifugal blower 1 of this embodiment, as described above, the casing rear plate 4 is provided with the circular recess 42, and the outer periphery of the ring member 16 is wrapped by the circular recess 42. The reverse flow A2 flowing into the gap 45 due to the Coanda effect on the outer surface of the ring member 16 is caused by the peripheral wall surface 42 a and the bottom wall surface 42 b of the circular recess 42 facing the outer surface of the ring member 16. It is deflected so as to follow the outer surface shape. As a result, due to the synergistic action of the Coanda effect and the deflection action, the backflow A2 does not flow greatly toward the center of the impeller 2 but circulates within a narrow range around the ring member 16. Thus, the reverse flow A2 is prevented from interfering with the main flow A1 and disturbing the flow as much as possible.

  Further, since the outer peripheral side of the ring member 16 is wrapped by the circular recess 42 of the casing rear plate 4, the ring member 16 has a structure as compared with the conventional structure without such a structure (see FIG. 19). The passage area of the air flowing into the outer peripheral side is reduced, the flow rate of the backflow A2 is reduced accordingly, and the backflow A2 interferes with the main flow A1 and disturbs the flow as much as possible.

  As a synergistic effect of these two, noise caused by the disturbance of the main flow A1 is reduced, and the silent operation of the centrifugal blower 1 is realized.

  Therefore, according to the present invention, it is possible to obtain a centrifugal blower having a shape that can be molded in two parts in the axial direction and having as good noise characteristics as possible (low specific noise level).

  In FIG. 24, the conventional centrifugal blower shown in FIG. 22 has a conventional structure (1), the conventional centrifugal blower shown in FIG. 23 has a conventional structure (2), and the above-mentioned first shown in FIGS. The centrifugal blower according to the first embodiment is used as the main structure, and each centrifugal blower is operated to show the lowest specific noise level. From this comparison diagram, it is confirmed that in the centrifugal blower having the structure of the present application, the operation noise is remarkably reduced as compared with those of the conventional structures.

<II: Second Embodiment>
Next, FIGS. 4 and 5 show a centrifugal blower 1 according to a second embodiment of the present invention. The centrifugal blower 1 has the same basic structure as that of the centrifugal blower 1 according to the first embodiment, and is different from the centrifugal blower 1 according to the first embodiment in the ring member 16. Is configured to have a substantially rectangular cross-sectional shape, whereas in the centrifugal blower 1 of this embodiment, the ring member 16 has a substantially hemispherical cross-sectional shape.

  As described above, when the cross-sectional shape of the ring member 16 is substantially hemispherical, the backflow A2 is more smoothly circulated around the ring member 16, and the Coanda effect is promoted accordingly. The silent drivability higher than that of the centrifugal blower 1 of the embodiment is realized.

  Since the structure and the effect other than the above are the same as in the case of the centrifugal blower 1 of the first embodiment, the same components corresponding to the components shown in FIGS. After adding a reference numeral, the corresponding description in the first embodiment is used, and the description here is omitted.

<III: Third Embodiment>
Next, FIGS. 6 and 7 show a centrifugal blower 1 according to a third embodiment of the present invention. This centrifugal blower 1 has the same basic structure as that of the centrifugal blower 1 according to the first embodiment, and is different from this in the configuration of the impeller 2.

  That is, the first difference is that in the centrifugal blower 1 in the first embodiment, the blade 13 is attached to the outer peripheral surface 11b of the main plate 11, whereas in the centrifugal blower 1 of this embodiment, The diameter of the main plate 11 is enlarged, and the main plate 11 is extended to a position substantially half of the base end side end surface 13e of the blade 13.

  If comprised in this way, the base end side end surface 13e of the said blade | wing 13 will be opened in the main plate 11 side, the reduction effect of the ventilation noise by raising the recirculation | circulation property of the backflow A2, and the coupling | bonding of the said main plate 11 and each blade | wing 13 will be demonstrated. It is possible to achieve both the durability improvement effect and the reliability improvement effect of the strength by increasing the strength.

  The second difference is that the impeller 2 in the first embodiment has a configuration including a shroud 12 (so-called shroud type), whereas the centrifugal blower 1 of this embodiment has the above-described configuration. This is a configuration without the shroud 12 (a so-called shroud type).

  By adopting such a configuration, in the centrifugal blower 1 provided with the shroudless type impeller 2, the circulation performance of the backflow A2 in the ring member 16 portion can be improved, and the effect of reducing the blowing noise can be obtained. The adaptability to the centrifugal blower 1 of the invention is improved.

  The third difference is that a reinforcing ring 18 is attached to the outer peripheral edge 13b of the tip 13d of the blade 13 for reinforcing the blade 13.

  With this configuration, in the centrifugal blower 1 including the shroudless type impeller 2, the blades can be reduced while ensuring the effect of reducing the blowing noise by increasing the circulation of the backflow A2 in the ring member 16 portion. The durability and strength reliability of the vehicle 2 can be increased.

  In addition, since a structure and an effect other than the above are the same as that of the case of the centrifugal blower 1 of the said 1st Embodiment, it is made to correspond to the structural member of FIG.1 and FIG.3 to the structural member of FIG.6 and FIG.7. After assigning the same reference numerals, the corresponding description in the first embodiment is used, and the description here is omitted.

<IV: Fourth Embodiment>
FIG. 8 shows an air conditioner Z to which the centrifugal blower 1 in the first embodiment is applied as a conditioned air blower as a fourth embodiment of the present invention. That is, this air conditioner Z is a ceiling-embedded air conditioner (indoor unit), and is mounted from the indoor side so as to close the casing 20 embedded in the ceiling and the lower surface opening of the casing 20. The centrifugal blower 1 is disposed in an interior space 25 formed by the indoor panel 21 so that the air suction port 6 faces the suction port 22 of the closed circuit 21, and the air blower of the centrifugal blower 1 is arranged. A heat exchanger 24 is arranged so as to cross the ventilation path from the outlet 7 to the air outlet 23 of the indoor panel 21.

  In the air conditioner Z, the operation of the centrifugal blower 1 causes the indoor air A01 sucked from the suction port 22 to be heat-exchanged in the heat exchanger 24 to be hot or cold conditioned air A02. 23 is blown into the room.

  In this air conditioner Z, since the blower applied to this is the centrifugal blower 1 according to the first embodiment, the characteristic of the centrifugal blower 1, that is, the low noise property is utilized, and the operation noise It is possible to provide an air conditioner with low noise and excellent quietness.

  In addition, although the example which applied the centrifugal blower 1 of the said 1st Embodiment as a blower is shown here, this invention is not limited to the structure which concerns, It is to said 1st-3rd embodiment. Any of the centrifugal blowers 1 can be applied.

<V: Fifth Embodiment>
Next, FIGS. 9 to 11 show the configuration of a centrifugal blower 1 according to a fifth embodiment of the present invention.

  The centrifugal blower 1 according to this embodiment has the same main structure as the centrifugal blower 1 according to the first embodiment, but the centrifugal blower 1 according to the first embodiment has the same structure as that of the fan casing 4. Predetermining the outer periphery of the ring member 16 having a substantially rectangular cross-sectional shape provided on the outer periphery of the blade 13 of the impeller 2 on the main plate 11 side by a circular concave groove formed in the thickness of the rear plate 41 In the centrifugal blower 1 of the fifth embodiment, for example, as shown in FIGS. 9 to 11, an inner portion of the rear plate 41 of the fan casing 4 is formed. On the side surface side, a circular recess 42 having a predetermined depth that opens to the main plate 11 side of the impeller 2 and wraps the outer periphery of the ring member 16 provided on the outer periphery of the blade 13 of the impeller 2 on the main plate 11 side. After such a fan casing 4 An annular cylindrical wall having a predetermined height provided outside the thickness of the rear plate 41 of the fan casing 4 and protruding toward the main plate 11 rather than by a circular concave groove portion recessed within the thickness of 41. It is characterized by being formed by No. 43.

  In the case of such a configuration as well, in the same manner as in the first embodiment, due to the Coanda effect on the outer surface of the ring member 16, the blades 13, 13. The backflow A2 on the main plate 11 side that re-flows into the space between the blades from the open end side is provided to protrude outside the plate thickness of the fan casing rear plate 41 by a predetermined height so as to wrap the outside of the ring member 16. The inner peripheral wall surface 42a of the circular recess 42 inside the annular cylindrical wall 43 is subjected to a deflection action along the outer surface shape of the ring member 16, and by the synergistic action of the Coanda effect and the deflection action. The circulating flow A2 has a small diameter that circulates only within a narrow range around the ring member 16 without greatly flowing to the center side of the impeller 2, and this counterflow A2 interferes with the mainstream A1 and flows therethrough. To disturb Suppress retroactively.

  In addition, when the outer peripheral side of the ring member 16 is wrapped by the circular concave portion 42 inside the annular cylindrical wall 43 provided outside the plate thickness of the fan casing rear plate 41 as described above, it is not so. On the other hand, the passage area of the air flowing into the outer peripheral side of the ring member 16 is reduced, and the flow rate of the backflow is reduced accordingly, so that the backflow A2 interferes with the main flow A1 and disturbs the flow. The phenomenon is more effectively suppressed.

  And as a synergistic effect of these two actions, the blowing noise resulting from the turbulence of the main flow A1 described above can be effectively reduced, and a centrifugal blower that is as quiet as possible can be provided. .

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Other configurations and operational effects are exactly the same as those of the centrifugal blower 1 of the first embodiment, so that the components shown in FIGS. 9 to 11 are replaced with the components shown in FIGS. By correspondingly attaching the same reference numerals, the description in the first embodiment is used, and the detailed description thereof is omitted.

<VI: Sixth Embodiment>
Next, FIGS. 12 and 13 show the configuration of a centrifugal blower 1 according to a sixth embodiment of the present invention.

  The centrifugal blower 1 according to this embodiment has the same main structure as the centrifugal blower 1 according to the second embodiment, but the centrifugal blower 1 according to the second embodiment has Predetermining the outer periphery of the ring member 16 having a substantially rectangular cross-sectional shape provided on the outer periphery of the blade 13 of the impeller 2 on the main plate 11 side by a circular concave groove formed in the thickness of the rear plate 41 In the centrifugal blower 1 of the sixth embodiment, for example, as shown in FIGS. 12 and 13, an inner portion of the rear plate 41 of the fan casing 4 is formed. On the side surface side, a circular recess 42 having a predetermined depth that opens to the main plate 11 side of the impeller 2 and wraps the outer periphery of the ring member 16 provided on the outer periphery of the blade 13 of the impeller 2 on the main plate 11 side. But such a fan casing An annular cylindrical shape having a predetermined height is provided to protrude toward the main plate 11 outside the thickness of the rear plate 41 of the fan casing 4 rather than by a circular concave groove portion recessed within the thickness of the rear plate 41. It is characterized by being formed by the wall 43.

  In the case of such a configuration, as in the case of the second embodiment described above, due to the Coanda effect on the outer surface of the ring member 16, the blades 13, 13,. The backflow A2 on the main plate 11 side that re-flows into the space between the blades from the open end side is provided to protrude outside the plate thickness of the fan casing rear plate 41 by a predetermined height so as to wrap the outside of the ring member 16. By the inner peripheral wall surface 42a of the circular recess 42 inside the annular cylindrical wall 43, a deflection action is applied along the outer surface shape of the ring member 16, and by the synergistic action of the Coanda effect and the deflection action, A large-diameter circulation flow A2 that circulates only within a narrow range around the ring member 16 does not flow greatly to the center side of the impeller 2, and this reverse flow A2 interferes with the main flow A1 and disturbs the flow. Possible It suppresses.

  In addition, when the outer peripheral side of the ring member 16 is wrapped by the circular concave portion 42 inside the annular cylindrical wall 43 provided outside the plate thickness of the fan casing rear plate 41 as described above, it is not so. On the other hand, the passage area of the air flowing into the outer peripheral side of the ring member 16 is reduced, and the flow rate of the backflow A2 is reduced accordingly, so that the backflow A2 interferes with the main flow A1 and the flow is reduced. The disturbing phenomenon is more effectively suppressed.

  And as a synergistic effect of these two actions, the blowing noise resulting from the turbulence of the main flow A1 described above can be effectively reduced, and a centrifugal blower that is as quiet as possible can be provided. .

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Other configurations and operational effects are the same as those of the centrifugal blower 1 of the second embodiment, so that the components shown in FIGS. 12 and 13 are replaced with the components shown in FIGS. 4 and 5 described above. By assigning the same reference numerals correspondingly, the description in the second embodiment is incorporated, and the detailed description thereof is omitted.

<VII: Seventh Embodiment>
Next, FIGS. 14 and 15 show the configuration of a centrifugal blower 1 according to a seventh embodiment of the present invention.

  The centrifugal blower 1 according to this embodiment has the same main structure as the centrifugal blower 1 according to the third embodiment, but the centrifugal blower 1 according to the third embodiment has Predetermining the outer periphery of the ring member 16 having a substantially rectangular cross-sectional shape provided on the outer periphery of the blade 13 of the impeller 2 on the main plate 11 side by a circular concave groove formed in the thickness of the rear plate 41 In the centrifugal blower 1 of the fifth embodiment, as shown in FIGS. 14 and 15, for example, the inside of the rear plate 41 of the fan casing 4 is formed. On the side surface side, a circular recess 42 having a predetermined depth that opens to the main plate 11 side of the impeller 2 and wraps the outer periphery of the ring member 16 provided on the outer periphery of the blade 13 of the impeller 2 on the main plate 11 side. But such a fan casing An annular cylindrical shape having a predetermined height is provided to protrude toward the main plate 11 outside the thickness of the rear plate 41 of the fan casing 4 rather than by a circular concave groove portion recessed within the thickness of the rear plate 41. It is characterized by being formed by the wall 43.

  In the case of such a configuration as well, as in the case of the third embodiment, due to the Coanda effect on the outer surface of the ring member 16, the blades 13, 13. The backflow A2 on the main plate 11 side that re-flows into the space between the blades from the open end side is provided to protrude outside the plate thickness of the fan casing rear plate 41 by a predetermined height so as to wrap the outside of the ring member 16. By the inner peripheral wall surface 42a of the circular recess 42 inside the annular cylindrical wall 43, a deflection action is applied along the outer surface shape of the ring member 16, and by the synergistic action of the Coanda effect and the deflection action, A large-diameter circulation flow A2 that circulates only within a narrow range around the ring member 16 does not flow greatly to the center side of the impeller 2, and this reverse flow A2 interferes with the main flow A1 and disturbs the flow. Of the Ri effectively suppress.

  In addition, when the outer peripheral side of the ring member 16 is wrapped by the circular concave portion 42 inside the annular cylindrical wall 43 provided outside the plate thickness of the fan casing rear plate 41 as described above, it is not so. On the other hand, the passage area of the air flowing into the outer peripheral side of the ring member 16 is reduced, and the flow rate of the backflow is reduced accordingly, so that the backflow A2 interferes with the main flow A1 and disturbs the flow. The phenomenon is suppressed as much as possible.

  And as a synergistic effect of these two actions, the blowing noise resulting from the turbulence of the main flow A1 described above can be effectively reduced, and a centrifugal blower that is as quiet as possible can be provided. .

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Other configurations and operational effects are exactly the same as those of the centrifugal blower 1 of the third embodiment, so that the components in FIGS. 14 and 15 are replaced with the components in FIGS. 6 and 7 described above. By correspondingly attaching the same reference numerals, the description in the third embodiment is used, and the detailed description thereof is omitted.

<VIII: Eighth Embodiment>
Next, FIGS. 16 and 17 show the configuration of a centrifugal blower 1 according to an eighth embodiment of the present invention.

  The centrifugal blower 1 according to this embodiment has the same main structure as the centrifugal blower 1 according to the fifth embodiment, but the fifth embodiment is different from the fan casing rear plate 41. Whereas the outer peripheral wall surface of the annular cylindrical wall 43 provided on the inner side surface is of the same diameter over the entire axial direction, the centrifugal blower 1 of this embodiment has, for example, FIGS. As shown, the outer diameter of the cylindrical wall 43 is not an equal diameter over the entire axial direction, but an inclined wall surface 43a whose diameter gradually increases from the main plate 11 side toward the rear plate 41 of the fan casing 4, The cross-sectional shape of the wall itself is formed in a substantially V shape.

  Thus, when the outer peripheral wall surface of the annular cylindrical wall 43 is an inclined wall surface 43a as shown in FIG. 17 whose diameter gradually increases from the main plate 11 side toward the rear plate 41 of the fan casing 4, the ring member 16 described above is used. The main flow A1 on the main plate 11 side, which is smoothly blown in the air flow outlet 7 side oblique flow centrifugal direction, is shown by arrows in FIG. As described above, the air is appropriately guided in the direction of the air outlet 7 and flows as smoothly as possible in the direction of the air outlet 7 on the inner surface side of the rear plate 41.

  As a result, the noise reduction effect is further improved.

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Since other configurations and operational effects are exactly the same as those of the centrifugal blower 1 of the fifth embodiment, the components shown in FIGS. 16 and 17 are replaced with the components shown in FIGS. 9 to 11 described above. By correspondingly attaching the same reference numerals, the description in the fifth embodiment is used, and the detailed description thereof is omitted.

<IX: Ninth Embodiment>
Next, FIG. 18 shows a configuration of a centrifugal blower 1 according to a ninth embodiment of the present invention.

  The centrifugal blower 1 of this embodiment has the same main structure as the centrifugal blower 1 according to the sixth embodiment, but the sixth embodiment is different from the fan casing rear plate 41 in that Whereas the outer peripheral wall surface of the annular cylindrical wall 43 provided on the inner side surface has the same diameter over the entire axial direction, in the centrifugal blower 1 of this embodiment, for example, as shown in FIG. The outer wall of the cylindrical wall 43 does not have an equal diameter over the entire axial direction, but is an inclined wall surface 43a whose diameter gradually increases from the main plate 11 toward the rear plate 41 of the fan casing 4, and the wall portion itself. The cross-sectional shape is formed in a substantially V shape.

  As described above, when the outer peripheral wall surface of the annular cylindrical wall 43 is the inclined wall surface 43a as shown in FIG. 18 whose diameter gradually increases from the main plate 11 side toward the rear plate 41 of the fan casing 4, the ring member 16 described above. The main layer A1 on the main plate 11 side that is smoothly blown out in the airflow outlet 7 side oblique flow centrifugal direction is indicated by an arrow in FIG. As described above, the air is appropriately guided in the direction of the air outlet 7 and flows as smoothly as possible in the direction of the air outlet 7 on the inner surface side of the rear plate 41.

  As a result, the noise reduction effect is further improved.

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Other configurations and operational effects are the same as those of the centrifugal blower 1 of the sixth embodiment, so that the components shown in FIG. 18 correspond to the components shown in FIGS. 12 and 13 described above. By attaching the same reference numerals, the description in the sixth embodiment is used, and the detailed description thereof is omitted.

<X: Tenth Embodiment>
Next, FIG. 19 shows a configuration of a centrifugal blower 1 according to a tenth embodiment of the present invention.

  The centrifugal blower 1 of this embodiment has the same main structure as the centrifugal blower 1 according to the seventh embodiment, but the seventh embodiment is different from the fan casing rear plate 41. Whereas the outer peripheral wall surface of the annular cylindrical wall 43 provided on the inner surface side has the same diameter over the entire axial direction, in the centrifugal blower 1 of this embodiment, for example, as shown in FIG. The outer wall of the cylindrical wall 43 does not have an equal diameter over the entire axial direction, but is an inclined wall surface 43a whose diameter gradually increases from the main plate 11 toward the rear plate 41 of the fan casing 4, and the wall portion itself. The cross-sectional shape is formed in a substantially V shape.

  Thus, when the outer peripheral wall surface of the annular cylindrical wall 43 is an inclined wall surface 43a as shown in FIG. 19 whose diameter gradually increases from the main plate 11 side toward the rear plate 41 of the fan casing 4, the ring member 16 described above. The main flow A1 on the main plate 11 side which is smoothly blown in the air flow outlet 7 side diagonal flow centrifugal direction is indicated by an arrow in FIG. As described above, the air is appropriately guided in the direction of the air outlet 7 and flows as smoothly as possible in the direction of the air outlet 7 on the inner surface side of the rear plate 41.

  As a result, the noise reduction effect is further improved.

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Other configurations and operational effects are exactly the same as those of the centrifugal blower 1 of the seventh embodiment, so that each component in FIG. 19 corresponds to each component in FIGS. 14 and 15 described above. By attaching the same reference numerals, the description in the seventh embodiment is used, and the detailed description thereof is omitted.

<XI: Eleventh Embodiment>
Next, FIG. 20 shows a configuration of a main part of a centrifugal blower 1 according to an eleventh embodiment of the present invention.

  The centrifugal blower 1 according to this embodiment has the same main structure as the centrifugal blower 1 according to the fifth embodiment, but the fifth embodiment is different from the fan casing rear plate 41. Whereas the outer peripheral wall surface of the annular cylindrical wall 43 provided on the inner surface side has the same diameter over the entire axial direction, in the centrifugal blower 1 of this embodiment, for example, as shown in FIG. The outer wall of the cylindrical wall 43 does not have an equal diameter over the entire axial direction, but has an inclined wall surface 43a whose diameter gradually increases from the main plate 11 toward the rear plate 41 of the fan casing 4, and a wall portion. The cross-sectional shape of itself is substantially trapezoidal.

  Thus, the cross-sectional shape of the annular cylindrical wall 43 is trapezoidal, and the outer peripheral wall surface thereof is an inclined wall surface 43a as shown in FIG. 20 whose diameter gradually increases from the main plate 11 side toward the rear plate 41 of the fan casing 4. Even in this case, the boundary layer is effectively eliminated by the small-diameter circulating flow A2 circulating only through the ring member 16 described above, and the main plate 11 side smoothly blown in the air outlet 7 side oblique flow centrifugal direction. As indicated by the arrow in FIG. 20, the main flow A1 is appropriately guided in the direction of the air outlet 7 so that the main flow A1 flows as smoothly as possible in the direction of the air outlet 7 on the inner surface side of the rear plate 41. Become.

  As a result, the noise reduction effect is further improved.

  Further, when the circular concave portion 42 is formed by such a cylindrical wall 43, the rear of the casing is compared with the case where a circular groove is formed in the plate thickness of the casing rear plate 41 as in the first to fourth embodiments. Since it is not necessary to increase the plate thickness of the plate 41, the passage cross-sectional area of the air outlet 7 can be ensured by that much, and the performance in a large air volume region is improved.

  Other configurations and operational effects are exactly the same as those of the centrifugal blower 1 of the fifth embodiment, so that the components shown in FIG. 20 correspond to the components shown in FIGS. 9 to 11 described above. By attaching the same reference numerals, the description in the fifth embodiment is used, and the detailed description thereof is omitted.

  The configuration of the annular cylindrical wall 43 having a trapezoidal cross section whose outer diameter gradually increases from the main plate 11 side to the rear plate 41 side of the fan casing 4 further relates to the sixth and seventh embodiments described above. Even when applied to the annular cylindrical wall 43 of the centrifugal blower 1, the same operation and effect can be obtained.

<XII: Twelfth Embodiment>
Next, FIG. 21 shows an air conditioner Z configured by applying the centrifugal blower 1 in the fifth embodiment to a blower for an air conditioner as a twelfth embodiment of the present invention.

  That is, this air conditioner Z is a ceiling-embedded air conditioner (indoor unit), and is mounted from the indoor side so as to close the casing 20 embedded in the ceiling and the lower surface opening of the casing 20. The centrifugal blower 1 according to the fifth embodiment is disposed in an in-machine space 25 formed by the indoor panel 21 so that the air suction port 6 faces the suction port 22 of the indoor panel 21. The heat exchanger 24 is arranged so as to cross the ventilation path from the air outlet 7 of the centrifugal blower 1 to the outlet 23 of the indoor panel 21.

  In the air conditioner Z, the indoor air A01 sucked from the suction port 22 by the operation of the centrifugal blower 1 is heat-exchanged in the heat exchanger 24 to be used as hot or cold conditioned air A02. 23 is blown into the room.

  In this air conditioner Z, since the blower applied to this is the centrifugal blower 1 according to the fifth embodiment, the characteristics of the centrifugal blower 1, that is, its low noise characteristics are utilized. It is possible to provide an air conditioner excellent in quietness with low operation noise.

  In addition, although the example which applied the centrifugal blower 1 of the said 5th Embodiment as a blower is shown here, this invention is not limited to the structure which concerns on the said 5th Embodiment, Of course, the said 1st. Any configuration of the centrifugal blower 1 according to each of the fifth to eleventh embodiments can be arbitrarily adopted to configure a similar air conditioner.

(Measurement of specific noise level)
When the specific noise level of each centrifugal fan of the fifth to twelfth embodiments is measured and viewed, the specific noise level of the first embodiment shown in FIG. The low noise characteristics are not inferior to

  Therefore, also from these results, according to the present invention, it is possible to obtain a centrifugal blower having the best possible noise characteristics (low specific noise level) with a shape that can be molded in two parts in the axial direction. What you can do becomes clearer.

1 is an overall cross-sectional view of a centrifugal blower according to a first embodiment of the present invention. It is a principal part disassembled perspective view of the centrifugal blower shown in FIG. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is a whole sectional view of a centrifugal blower concerning a 2nd embodiment of the invention in this application. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is whole sectional drawing of the centrifugal blower which concerns on 3rd Embodiment of this invention. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is a whole sectional view of an air harmony machine concerning a 4th embodiment of the invention in this application. It is a whole sectional view of a centrifugal blower concerning a 5th embodiment of the invention in this application. It is a principal part meeting perspective view of the centrifugal air blower shown in FIG. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is a whole sectional view of a centrifugal blower concerning a 6th embodiment of the invention in this application. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is a whole sectional view of a centrifugal blower concerning a 7th embodiment of the invention in this application. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is a whole sectional view of a centrifugal blower concerning an 8th embodiment of the invention in this application. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower shown in FIG. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower which concerns on 9th Embodiment of this invention. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower which concerns on 10th Embodiment of this invention. It is an expanded sectional view of the main plate outer periphery vicinity of the centrifugal blower which concerns on 11th Embodiment of this invention. It is a whole sectional view of an air harmony machine concerning a 12th embodiment of the invention in this application. It is a whole sectional view showing a centrifugal blower concerning the 1st conventional structure. It is a whole sectional view showing a centrifugal blower concerning the 2nd conventional structure. It is contrast explanatory drawing of the specific noise level of a centrifugal blower.

DESCRIPTION OF SYMBOLS 1 ... Centrifugal blower 2 ... Impeller 3 ... Casing front board 4 ... Casing rear board 5 ... Bell mouth 6 ... Air inlet 7 ... Air blower 11 ... Main plate 12 ・ ・ ・ Shroud 13 ・ ・ ・ Blade 14 ・ ・ ・ Motor 15 ・ ・ ・ Boss 16 ・ ・ ・ Ring member 18 ・ ・ ・ Reinforcement ring 20 ・ ・ ・ Casing 21 ・ ・ ・ Indoor panel 22 ・ ・ ・ Suction port 23 ... Air outlet 24 ... Heat exchanger 41 ... Side extension 42 ... Circular recess 43 ... Annular cylindrical wall 43a ... An inclined wall surface on the outer periphery of the cylindrical wall 45 ... Gap Z ... Air conditioner

Claims (8)

  A main plate that is rotationally driven, a plurality of blades arranged side by side on the outer periphery of the main plate with a predetermined interval in the circumferential direction and with the end surface on the main plate side opened, and the main plate side of the plurality of blades A centrifugal blower comprising a ring member provided on the outer peripheral surface of the end portion and a casing rear plate provided on the back side of the main plate, wherein the casing rear plate is open to the main plate side, A centrifugal blower characterized in that a circular recess for wrapping the outer periphery of the ring member is provided.   A large number of blades are arranged upright at predetermined intervals in the circumferential direction with respect to the rotationally driven main plate, and an annular ring member is provided on the outer peripheral surface of the blade on the base end side. In the centrifugal blower provided with the impeller provided with a casing, a casing rear plate is disposed so as to face the back surface of the main plate, and the casing rear plate is open to the main plate side and has an outer periphery of the annular ring member. A centrifugal blower comprising: a circular concave portion for wrapping the portion; and a laterally extending portion extending continuously outward in the radial direction on the outer peripheral edge portion on the open side of the circular concave portion.   The centrifugal blower according to claim 1 or 2, wherein the circular concave portion is formed by a circular concave groove portion provided to be recessed in a thickness of the casing rear plate.   The centrifugal blower according to claim 1, wherein the circular recess is formed by an annular cylindrical wall that is erected in the main plate side direction from the main plate side inner surface of the casing rear plate. The surface of the said side extension part of the said rear plate of the said casing and the inner surface of the said main plate are set so that it may be located in the substantially the same position in the axial direction of the said impeller. Centrifugal blower.   The centrifugal blower according to claim 1, 2, 3, 4, or 5, wherein the impeller has a configuration in which a shroud is provided on a front end side end face of the blade.   The centrifugal blower according to claim 1, 2, 3, 4, or 5, wherein the impeller has a configuration in which a shroud is not provided on a front end side end face of the blade.   An air conditioner in which a heat exchanger and a blower are arranged before and after the air passage from the air inlet to the air outlet in a casing having an air inlet and an air outlet, An air conditioner comprising the centrifugal blower according to claim 1, 2, 3, 4, 5, 6 or 7 as a blower.

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