JP2009281215A - Air conditioner indoor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an air conditioner indoor unit thin, and to reduce noise. <P>SOLUTION: A pair of right and left heat exchangers in each of a pair of right and left air paths extending from the middle part of an indoor unit casing to right and left air blowoff port are provided in such a manner that a mutual space is narrow at a front face side of the indoor unit casing, and slanted so as to form a wide truncated chevron shape at a rear side. On the other hand, a centrifugal blower includes a plurality of blades 12, a main plate 10 for supportingly fix one end side of a span direction of the plurality of blades keeping a predetermined space in a circumferential direction, a ring-shaped side plate 11 provided at the other end side of the span direction of the plurality of blades, and a blade driving means 8 for rotating the plurality of blades via the main plate. The main plate side is located at the rear side of the indoor unit casing, and the side plate side at the front side of the indoor unit casing, and the plurality of blades are formed so that a radial length of the main plate side is longer than a radial length of the side plate side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure of an indoor unit for an air conditioner in which an indoor unit main body is thinned.

  Recently, attempts have been made to reduce the dimension in the depth direction of the indoor unit casing of an indoor unit for an air conditioner so as to make it as thin as possible (see, for example, Patent Document 1).

  In the thing of the said patent document 1, the aluminum laminated type heat exchanger with small and high heat exchange efficiency is arrange | positioned on the right and left of the centrifugal blower which shortened the length of the rotating shaft direction, and the front side center part of an indoor unit casing is arranged. The air sucked from the air inlet is blown forward from the air outlets on both the left and right sides through these heat exchangers, so that the indoor unit body can be made as thin as possible.

  In an indoor unit for an air conditioner in which a heat exchanger and a centrifugal fan are arranged in such a casing, the depth direction is made as compact as possible without reducing the original heat exchange performance of the air conditioner (thin type) In order to maintain the heat exchange capacity of the heat exchanger and the air flow rate of the centrifugal fan at a necessary and sufficient level, the centrifugal fan, heat exchanger, and air passage must be made as compact as possible. There is.

  However, the downsizing of the centrifugal blower causes a reduction in the amount of air blown, and the downsizing of the heat exchanger causes a reduction in heat exchange capacity. Further, downsizing of the air passage increases the pressure loss of the blower and has an adverse effect such as an increase in the rotational speed and an increase in the blowing sound. For this reason, there is a demand for a structure of an indoor unit structure that does not have such drawbacks, and a high-performance centrifugal blower that can achieve noise reduction with a high static pressure and a large air volume suitable for the indoor unit structure.

JP 2006-29702 A

  In the case of the above-mentioned Patent Document 1, a centrifugal blower provided with blades of equal diameter in the front-rear direction in which the length in the rotation axis direction is shortened is sandwiched in the air passage in the indoor unit casing which is thinned by reducing the depth dimension in the front-rear direction Thus, a pair of stacked heat exchangers are installed in parallel to each other, and the length in the span direction of the blades of the centrifugal fan is reduced by the amount of shortening the length in the rotation axis direction, descend.

  In addition, the front-rear width of the stacked heat exchanger is reduced by the amount by which the depth dimension of the indoor unit casing is reduced, and the heat exchange capability is reduced.

  Furthermore, the air passage cross-sectional area is reduced by reducing the depth dimension of the indoor unit casing, and the pressure loss of the centrifugal blower is increased. It causes an increase and an increase in blowing sound.

  That is, in the case of the configuration of Patent Document 1, the indoor unit itself is thinned, but the above-described problem is not realized.

  The present invention has been made to solve such a problem. In the indoor unit for an air conditioner having a reduced depth dimension in the front-rear direction as described above, the pair of left and right heat exchangers are arranged in the indoor unit casing. In each of the pair of air passages extending from the central portion to the left and right air outlets, the air passages are provided so as to be inclined so as to form a narrow letter C on the front side of the indoor unit casing and on the rear side. While ensuring the necessary heat exchange area while reducing the depth dimension of the centrifugal fan, the centrifugal fan is installed so that its main plate side is located on the back side of the indoor unit casing where the space between the heat exchangers is wide In addition, by forming the radial length of the plurality of blades on the main plate side longer than the side plate side, the speed of the air flow main flow portion blown out from the impeller is improved, and the main flow is more An air conditioner that allows air to flow more efficiently by deflecting it toward the main plate with sufficient air passage, avoiding the blown airflow immediately after the blades from directly colliding with the heat exchanger. The purpose is to provide an indoor unit.

  In order to achieve the above object, the present invention comprises the following problem solving means.

(1) Invention of Claim 1 This invention is a thin indoor unit casing with a small depth dimension in the front-rear direction, an air inlet provided in the front side central portion of the indoor unit casing, and the front surface of the indoor unit casing. A pair of air outlets provided on the left and right sides, a pair of left and right air passages inside the indoor unit casing and continuing from the air inlet to the pair of left and right air outlets, and the pair of left and right air passages A centrifugal blower provided on the upstream side of each of the air suction ports and provided on the downstream side of the pair of left and right air passages and provided on the downstream side of the pair of left and right air passages. An air conditioner indoor unit comprising a pair of left and right heat exchangers, wherein the pair of left and right heat exchangers are a pair of left and right air extending from a central portion in the indoor unit casing to the left and right air outlets. In each of the passages While the interval between each other is narrow at the front side of the indoor unit casing and is inclined so as to form a wide C shape at the back side, the centrifugal blower includes a plurality of blades and the plurality of blades A main plate for supporting and fixing one end side of the span direction in the circumferential direction at a predetermined interval, a ring-shaped side plate provided on the other end side of the plurality of blades in the span direction, and the plurality of sheets via the main plate Blade driving means for rotating the blades, the main plate side is located on the back side of the indoor unit casing, the side plate side is located on the front side of the indoor unit casing, and the plurality of blades are The radial length on the main plate side is longer than the radial length on the side plate side.

  According to such a configuration, first, the pair of left and right heat exchangers are spaced apart from each other in each of the pair of air passages extending from the central portion in the indoor unit casing to the left and right air outlets with the centrifugal fan interposed therebetween. Since it is provided with an inclination so as to form a narrow letter C on the front side and wide on the back side, the dimension in the depth direction of the indoor unit casing of the indoor unit for the air conditioner can be reduced as much as possible. Even if the thickness is reduced, necessary and sufficient heat exchanger dimensions can be secured. Therefore, it is possible to reduce the size of the indoor unit body in the depth direction without deteriorating the original heat exchange performance of the heat exchanger of the air conditioner indoor unit.

  Next, the centrifugal blower has a plurality of blades, a main plate that supports and fixes one end side in the span direction of the plurality of blades at a predetermined interval in the circumferential direction, and the other end side in the span direction of the plurality of blades. It comprises a ring-shaped side plate provided and blade driving means for rotating the plurality of blades via the main plate, and the main plate side is located on the back side of the indoor unit casing.

  Accordingly, the main plate side portion through which the main flow of the plurality of blades of the centrifugal blower flows corresponds to the wide back side portion between the pair of left and right heat exchangers, and heat exchange with the blades is performed on the back side portion. Since the air passage with a small pressure loss and a large margin is formed, the main flow part from the impeller is displaced to the main plate side of each blade, and it is efficiently blown out with low pressure loss In the heat exchanger portion, a uniform wind speed distribution is passed through substantially the whole.

  As a result, the drift of the air flow flowing in the heat exchanger is also eliminated, and the heat exchange efficiency of the heat exchanger is improved.

  Moreover, it can avoid that the blowing airflow immediately after a blade | wing collides directly with a heat exchanger part, and can ventilate more efficiently.

  Further, in the above configuration, in addition to these configurations, each of the plurality of blades is formed such that the radial length on the main plate side is longer than the length on the side plate side.

  Thus, when the radial length on the main plate side of each blade is longer than the radial length on the side plate side, the blade mainstream portion is displaced to the main plate side and flows through the air passage portion having a wide interval from the heat exchanger. Velocity distribution is greatly improved, the static pressure-flow rate characteristics are improved in the entire flow rate range, the air flow rate is increased, and the specific noise characteristics are also greatly improved, occurring downstream of the trailing edge of the blade main plate side. The influence of the wake vortex can be weakened relatively. As a result, noise due to the wake vortex is also effectively reduced.

  With these configurations, in the present invention, it is possible to obtain a necessary and sufficient air flow rate without increasing the rotational speed. Further, by reducing the rotational speed as much as possible, the swirl component of the blown airflow can be reduced, and the noise generated from the blower impeller can be suppressed.

  As a result, noise reduction is effectively achieved in all wind regions.

(2) Invention of Claim 2 This invention is the structure of invention of said Claim 1, The main plate side radial direction length of a blade | wing is a side plate by extending the trailing edge part of a blade | wing long back to an air blowing direction. It is characterized by being formed longer than the side.

  In this way, if the radial length of the blade main plate side is made longer than the side plate side by extending the trailing edge of the blade longer to the rear of the air flow, as described above, it is displaced to the main plate side and heat exchange is performed. The speed distribution of the main blade part that flows through the air passage part with a wide space between the air conditioner is greatly improved, the static pressure-flow rate characteristic is improved in the entire flow rate range, the air flow rate is effectively increased, and the specific noise characteristic is also greatly improved. Thus, the influence of the wake vortex generated at the trailing edge of the blade main plate can be relatively weakened. As a result, noise due to the wake vortex is effectively reduced.

  In addition, even if the speed of the mainstream part is improved in this way, the airflow from the blades should not directly collide with the heat exchanger part because the distance from the heat exchanger is wide in the part where the mainstream flows. Thus, the air can be blown more efficiently.

  As a result, the necessary air volume can be obtained without increasing the rotational speed, and by reducing the rotational speed, the swirl component of the airflow can be reduced and the noise generated from the impeller can be suppressed.

  As a result, noise reduction is effectively achieved in all wind regions.

  In the above case, more preferably, the length of the trailing edge of the blade is extended to the rear in the air blowing direction, and the diameter of the main plate is further extended to match the length of the impeller of the centrifugal fan. The structural strength can be improved at the same time.

(3) Invention of Claim 3 This invention is the structure of invention of the said Claim 1, The main plate side radial direction length of a blade | wing is based on the distance between a blade | wing and a heat exchanger at the trailing edge part of a blade | wing. As the distance increases, it extends longer in the air blowing direction and is longer than the side plate.

  As described above, when the length of the blade in the radial direction on the main plate side is made longer than that on the side plate side, the trailing edge of the blade is extended longer in the air blowing direction as the distance increases according to the distance between the blade and the heat exchanger. Therefore, if the length is longer than the side plate side, the main flow part of the air flow blown out from the impeller will be shifted to the main plate side where there is more room in the air passage, and the blowout from the blades The velocity distribution of the airflow is in accordance with the distance from the heat exchanger, and it is possible to avoid the direct collision with the heat exchanger portion effectively according to the velocity distribution and to blow air more efficiently.

  Thereby, the required air volume can be obtained without increasing the rotational speed. Further, by reducing the rotational speed, the swirl component of the airflow can be reduced and the noise generated from the impeller can be suppressed.

  As a result, noise reduction is effectively achieved in all wind regions.

(4) Invention of Claim 4 This invention is the structure of the said invention of Claim 2 or 3, The blade trailing edge extended long back in the air blowing direction is gradually linearly from the side plate side to the main plate side. It is characterized by being extended to be longer.

  According to such a configuration, the shape of the trailing edge of the blade becomes a tapered shape that is enlarged by a linear change from the side plate side to the main plate side, and is suitable for the change in the velocity distribution of the blown airflow that is displaced to the main plate side. It can be made compatible.

(5) Invention of Claim 5 This invention is the structure of the said invention of Claim 2 or 3, The blade trailing edge extended long back in the air blowing direction is gradually curved from the side plate side to the main plate side. It is characterized by being extended to be longer.

  According to such a configuration, the shape of the trailing edge of the blade becomes a tapered shape that is enlarged by a curvilinear change from the side plate side to the main plate side. It can be appropriately handled.

  As a result, the fan performance can be further improved.

(6) Invention of Claim 6 This invention is the structure of the invention of said Claim 5, and the rear edge extended so that it may become gradually curvilinear from the side-plate side to the main-plate side is an extension of the same curvilinear form. One or more inflection points exist in the middle of the portion, thereby forming a bulging portion located on the main plate side.

  In the centrifugal blower as described above, the airflow in the vicinity of the main plate forms a laminar shear layer due to the influence of viscosity due to the wall surface of the main plate, thereby narrowing the main flow path and reducing the fan performance.

  However, if the bulging portion that bulges smoothly on the main plate side as described above is provided, the development of the shear layer can be effectively suppressed and the fan performance can be improved.

(7) Invention of Claim 7 This invention is the structure of the invention of the said Claim 1, 2, 3, 4, 5 or 6 WHEREIN: The main plate side part of a blade | wing front edge part is a predetermined length ahead in an air suction direction. It is characterized by providing an extended step.

  With such a configuration, when the air flow sucked into the impeller of the blower through the air suction port is blown rearward from the blade trailing edge, the air flow to be separated from the suction surface side of the blade is effectively prevented. The noise of the blower can be further effectively reduced.

(8) Invention of Claim 8 This invention is the configuration of the invention of Claim 1, 2, 3, 4, 5, 6 or 7, wherein the pair of left and right air passages are each formed with a scroll portion, The length of the blade trailing edge extended in the air blowing direction is set according to the installation position of the scroll portion.

  When there is a scroll part in the air passage, if the trailing edge of each blade approaches the scroll part by a predetermined distance or more, it is discrete (number of revolutions [rps] ××) due to interference between the blowing airflow and the scroll part (solid wall). Interference sound (so-called NZ sound) of the number of blades [sheets] × n: n = natural number) is generated.

  Therefore, when there is a scroll part in the air passage, the extension amount of the extended trailing edge of the blade is also determined within a range that does not generate the interference sound so as not to make the distance between each blade and the scroll part too close. Is done.

(9) Invention of Claim 9 This invention is the structure of the invention of Claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the plurality of blades are respectively provided between the main plate and the side plate. It is characterized by a three-dimensional blade extending in the axial direction while twisting.

  Thus, when each of the plurality of blades is formed by a three-dimensional blade extending in the axial direction while twisting between the main plate and the side plate, the blade is made based on a conventional blade element drawn in a plane. Compared with the two-dimensional blade shape, the load distribution on the blade surface and the pressure fluctuation of the airflow passing between the blades are greatly improved.

  Therefore, a further effect can be obtained by combining the structure of the invention according to claims 1, 2, 3, 4, 5, 6, 7 or 8 having the above-described action on such a three-dimensionally shaped blade. Thus, the influence of the wake vortex can be eliminated.

  As a result of the above, according to the present invention, it is possible to provide an indoor unit for an air conditioner that is as compact as possible and excellent in silence while maintaining necessary and sufficient heat exchange capacity and air flow rate. It becomes.

  FIGS. 1-9 has shown the structure of the whole indoor unit for air conditioners based on the best embodiment of this invention comprised as a floor type thing as an example, and each part.

  In FIG. 1 showing the overall configuration of the air conditioner indoor unit 1, first, reference numeral A denotes a depth dimension (product thickness) W in the front-rear direction of the air conditioner indoor unit 1 as small as possible. This is a thin main body casing. The main casing A has an intake / blowout panel (front plate) 4 on the front side, a rear panel (back plate) 2 serving as a fan motor mounting surface on the back side, and side panels (side plates) 3 and 3 on the left and right sides. A top panel (top plate: not shown) is provided on the upper surface side, and a lower panel (bottom plate: not shown) is provided on the lower surface side.

  The front side intake / blowout panel 4 of the main body casing A is provided with a bell mouth 5 having a bell mouth-shaped air suction port 5a formed at the center, and further, a centrifugal blower is coaxially arranged inside thereof. As an example, a turbo fan 13 is continuously provided.

  As shown in FIGS. 1, 3, and 4, for example, the turbo fan 13 has a plurality of blades 12, 12... And one end side in the span direction of the plurality of blades 12, 12. The main plate 10 is supported and fixed at a predetermined interval in the circumferential direction, the ring-shaped side plate 11 provided on the other end side in the span direction of the plurality of blades 12, 12. The fan motor 8 that rotates the plurality of blades 12, 12... Has a main plate 10 side on the back panel 2 side of the main body casing A of the indoor unit 1 and a side plate 11 side on the indoor unit main body casing A. The front side air intake / outlet panel 4 is located.

  The main plate 10 is supported by attaching the central portion 10a side where the concave groove portion is formed to the drive shaft 8a of the fan motor 8, and the blades 12, 12,... Are attached to the flat outer peripheral portion 10b.

  The turbo fan 13 has a length in the rotational axis direction (including the length in the span direction of the blades 12, 12...) In accordance with the reduction in the depth dimension W of the indoor unit main body casing A. It is configured to be as short as possible.

  Further, the shape of the blades 12, 12... Is a three-dimensional shape extending between the main plate 10 and the side plate 11 and extending in the span direction while being twisted in the opposite rotation directions as shown in FIGS. It has a shape.

  In addition, a pair of rectangular air outlets 7 and 7 extending in the vertical direction with a predetermined width are provided on the left and right sides of the air inlet 5a of the front side intake / outlet panel 4 of the main body casing A.

  In the main body casing A, a pair of left and right air passages 6, 6 extending from the bell mouth-shaped air suction port 5a to the left and right air outlets 7, 7 are formed. The above-described turbo fan 13 is installed in the form in which the front end 11a of the air suction side plate 11 is fitted to the outside, located behind the air suction port 5a of the passages 6 and 6, and the drive shaft 8a and the fan motor 8 Is fixed to the rear panel 2 of the main casing A.

  The air passages 6 and 6 are provided with a pair of left and right air heat exchangers 9 and 9 at positions corresponding to the downstream air outlets 7 and 7 with the turbo fan 13 sandwiched from the left and right. ing. The pair of left and right air heat exchangers 9 and 9 include, for example, as shown in FIG. 2, flat heat transfer tubes (multi-hole tubes) 9a, 9a... And flat heat transfer fins (corrugated fins as an example) 9b, 9b... It is composed of a compact aluminum laminated heat exchanger with extremely high heat transfer performance, provided with refrigerant headers 20a, 20b, 20a, 20b on the lower side. The refrigerant pipes 21a and 21b are connected to the refrigerant headers 20a, 20b, 20a, and 20b so that the refrigerant is supplied.

  The pair of left and right air heat exchangers 9 and 9 are each formed to have a rectangular parallelepiped shape as a whole, and the flat heat transfer tubes 9a, 9a..., Flat heat transfer fins 9b, 9b. In each of the pair of left and right air passages 6 and 6 extending left and right from the center portion in the indoor unit main body casing A so that the air passages 6 and 6 extend along the air flow direction of the air passages 6 and 6. The main body casing A is provided so as to be inclined so as to form a letter C in a narrow manner on the front side intake / blowout panel 4 side and on the other side of the rear panel 2 side.

  In this way, the pair of left and right air heat exchangers 9 and 9 are spaced apart from each other at the front of the indoor unit main body casing A in each of the pair of air passages 6 and 6 extending left and right from the central portion in the indoor unit main body casing A. As shown in FIG. 1, the length in the front-rear direction is narrow so that the side intake / blowout panel 4 is narrow and the back panel 2 is wide to form a wide letter C. The length of the indoor unit casing A can be increased while ensuring a sufficient heat exchange area as a whole. It can be made as small as possible, and the thickness can be further reduced.

  The air heat exchangers 9 and 9 of the same pair have rear end sides at the rear corners of the air passages 6 and 6, front end sides at the bell mouth 5 side of the intake / outlet panel 4, and further lower end sides. It is supported by positioning and fixing on a drain pan at the bottom of the main body casing (not shown).

  However, the turbo fan 13 having a reduced length in the direction of the rotation axis is provided in the air passages 6 and 6 in the indoor unit main body casing A which is thinned by reducing the depth dimension in the front-rear direction. When the pair of stacked air heat exchangers 9 and 9 are installed, the length in the span direction of the blades 12, 12,... It becomes shorter and the air flow rate is reduced.

  Moreover, the front-rear widths of the stacked air heat exchangers 9 and 9 are reduced by the amount by which the depth dimension W of the indoor unit casing A is reduced, and the heat exchange capability is reduced.

  Furthermore, since the cross-sectional area of the air passages 6 and 6 is reduced by an amount corresponding to the reduction of the depth dimension W of the indoor unit casing A, the pressure loss of the turbo fan 13 is increased. This increases the driving load and increases the blowing sound.

  Therefore, in this embodiment, the plurality of blades 12, 12,... Of the turbo fan 13 have the rear edges 12b, 12b,. By extending from the side plate 11 side to the main plate 10 side so as to become gradually longer linearly, the radial length on the main plate 10 side is formed longer than the radial length on the side plate 11 side.

  In this case, for example, the length of the blades 12, 12... In the radial direction of the main plate 10 is the same as that of the rear edges 12 b, 12 b. -The air heat exchangers 9 and 9 are formed to be longer than the side plate 11 side by extending longer in the air blowing direction in accordance with the distance between the air heat exchangers 9 and 9.

In other words, the trailing edge 12b of the blades 12, 12... In this embodiment has its main plate 10 side and side plate 11 side parallel to the axial direction (perpendicular to the main plate 10) as in the conventional example. ... that is, the outer diameter Da of the side plate 11 and the outer diameter Db of the main plate 10 in FIG. 8 are not connected by a straight line, but, for example, as shown in FIGS. As the distance from the side plate 11 to the main plate 10 becomes closer to the main plate 10 side (the distance between the rear edge portion 12b and the air heat exchanger 9 becomes larger), the length of the air flow increases backward. Thus, the radial direction length (blade chord length) on the main plate 10 side through which the main flow F ₁ of the turbo fan 13 passes is made longer than that on the side plate 11 side, whereby the air flow in the blade span direction as shown in FIG. Is effective on the main plate 10 side. And to reach (F _1> F _2).

  Of course, the extension of the trailing edge portion 12b is performed without changing the shape of the blade surface of the three-dimensional wing, and is performed along the shape change.

  Further, in this case, of course, the outer diameter of the main plate 10 itself is also increased in accordance with the increase in the radial direction length of the blade 12 on the main plate 10 side (see Db → Db ′ in FIG. 8: Db ′> Db).

  In this way, if the length of the main plate 10 is further extended in accordance with the extension of the length of the blade trailing edge portion 12b, the structural strength of the turbofan impeller can be improved at the same time.

  In this case, the extension amount of the blade trailing edge 12b is the outer diameter Db (FIG. 8) of the main plate 10 in the case of the blade 12 having the trailing edge shape parallel to the original fan rotation axis (perpendicular to the main plate 10). Considering the standard, the outer diameter Db ′ of the enlarged main plate 10 is preferably a size up to 10% increase of the outer diameter Db of the original main plate 10.

  In addition, when extending the trailing edge 12b, the blade blade inlet angle, outlet angle, mounting angle, skew angle, etc. of the blade 12 on the main plate 10 side are kept at the values of the original blade 12. preferable.

When the turbo fan 13 having such a configuration is provided between a pair of left and right air heat exchangers 9 and 9 that are installed so as to be inclined in a C shape as shown in FIG. 1, for example, as shown in FIG. as a plurality of blades 12, 12 the main flow F ₁ is the main plate 10 side portion flowing of ... the fan 13, the width between the pair of the heat exchanger 9, 9 each other corresponding to the wide rear panel 2 side portion In addition, in the rear panel 2 side portion, the distance between the blades 12, 12,... And the heat exchangers 9, 9 is large, and air passages 6 and 6 having a small pressure loss are formed. The main flow F ₁ portion from the 13 impellers is displaced toward the main plate 10 side of each blade so that it is efficiently blown out with a low pressure loss, and the heat exchangers 9 and 9 have a uniform wind speed over substantially the whole. It becomes a distribution and passes.

  As a result, the drift of the air flow flowing in the heat exchangers 9 and 9 is also eliminated, and the heat exchange efficiency of the heat exchangers 9 and 9 is improved.

  Moreover, it can avoid that the blowing airflow immediately after impeller outflow collides directly with the heat exchangers 9 and 9 part, and can ventilate more efficiently.

  Thereby, for example, as shown in FIG. 10, a necessary air volume can be obtained without increasing the number of revolutions compared to the conventional one (Db = Da in FIG. 8). Further, by reducing the rotational speed, the swirl component of the airflow can be reduced and the noise generated from the impeller can be suppressed.

  As a result, as shown in FIG. 11, for example, noise reduction can be effectively achieved in the entire air volume range as compared with the conventional one.

  This is because the spectrum is relaxed as compared to the conventional blower as shown in FIG.

Further, as described above, by extending the rear edge portion 12b of the blades 12, 12, ... to the rear of the air flow, the radial length on the main plate 10 side of the blade 12 is made longer than the side plate 11 side. The velocity distribution of the blade main flow F ₁ portion that is displaced toward the main plate 10 side is greatly improved, the static pressure-flow rate characteristic is improved in the entire flow rate range, the air flow rate is increased, and the specific noise characteristic is also greatly improved. As a result, the influence of the wake vortex generated at the trailing edge of the three-dimensional blade 12 on the main plate 10 side can be relatively weakened.

  As a result, noise caused by the wake vortex can be effectively reduced.

  Therefore, the noise reduction effect is further improved.

Further, as described above, when the radial length of the blades 12, 12... In the main plate 10 side is longer than the side plate 11 side, the blades 12, 12. .. If the length of the heat exchangers 9 and 9 is longer than the side plate 11 by extending backward in the air blowing direction as the distance increases, the air is blown from the impeller of the turbo fan 13. The main flow F ₁ portion of the air flow is displaced more toward the main plate 10 side where the air passages 6 and 6 have more margins, and flows more smoothly. Avoiding a direct impact on the heat exchangers 9 and 9 can be avoided and the air can be blown more efficiently.

  Further, in this embodiment, in the above case, the blade trailing edge portion 12b extended long backward in the air blowing direction is extended so as to be gradually increased linearly from the side plate 11 side to the main plate 10 side. Yes.

According to such a configuration, the shape of the blade trailing edge 12b becomes a tapered shape that is enlarged by a linear change from the side plate 11 side to the main plate 10 side as shown in FIG. It is possible to appropriately cope with a change in the velocity distribution of the main flow F ₁ .

  Further, in this embodiment, in the above configuration, the plurality of blades 12, 12... Are configured by three-dimensional blades 12, 12.

  In this way, when each of the plurality of blades 12, 12... Is formed of a three-dimensional blade, the two-dimensional blade made on the basis of a conventional planarly drawn blade element. Compared with the shape, the load distribution on the blade surface and the pressure fluctuation of the airflow passing between the blades are greatly improved.

  Therefore, when the above-described configuration is further combined with the three-dimensional blade having such an action, the influence of the wake vortex can be more effectively eliminated.

  As a result, according to this embodiment, it is possible to provide an indoor unit for an air conditioner that is sufficiently compact and excellent in quietness while maintaining necessary and sufficient heat exchange capacity and air flow rate. Become.

(Modification 1)
In the above configuration, the blade trailing edge portion 12b that is extended to the rear in the air blowing direction is extended so as to gradually become longer in a curved shape from the side plate 11 side to the main plate 10 side, for example, as shown in FIG. You may do it.

According to such a configuration, the shape of the blade trailing edge portion 12b becomes a tapered shape that is enlarged by a curvilinear change from the side plate 11 side to the main plate 10 side, and the velocity distribution of the main flow F ₁ that is displaced toward the main plate 10 side. Can respond appropriately to changes in

(Modification 2)
Further, in the configuration of the first modification, the rear edge portion 12b extended so as to gradually become longer in a curved shape from the side plate 11 side to the main plate 10 side is, for example, as shown in FIG. There may be one or more inflection points in the middle of the portion, thereby forming the bulging portion 12c located on the main plate 10 side.

In the centrifugal fan such as the turbo fan 13 described above, the airflow in the vicinity of the main plate 10 forms a laminar shear layer due to the influence of the viscosity of the wall surface of the main plate 10, thereby narrowing the flow path of the main flow F ₁ and improving fan performance. May fall.

  However, when the bulging portion 12c that bulges smoothly on the main plate 10 side is provided as described above, the development of the shear layer can be effectively suppressed and the fan performance can be improved.

(Modification 3)
The front edge portions 12a, 12a,... Of the three-dimensional blades 12, 12,... Of the present embodiment are further stepped toward the inner peripheral side of the impeller as shown in FIG. Then, you may make it provide the 1st, 2nd step part 12d and 12e which protrude in 2 steps | paragraphs. The first and second sets of stepped portions 12d and 12e are arranged so that the airflow sucked into the impeller of the turbofan 13 through the air inlet 5a of FIG. When the air is blown out, it is possible to suppress separation from the suction surface side of the blades 12, 12..., Thereby contributing to further reducing the blowing noise of the blower.

(Modification 4)
Furthermore, in this embodiment, as shown in FIGS. 16 and 17, for example, supercooling heat exchangers 19 and 19 that function as a condenser during heating operation and function as an evaporator during cooling operation are provided as necessary. It is done. The subcooling heat exchangers 19 and 19 are disposed substantially symmetrically on the front side (side plate 11 side) of each of the pair of left and right air heat exchangers 9 and 9 on the air outlet 7 and 7 side of the turbo fan 13. Is done.

In the case of such a configuration, the pressure loss of the side plate 11 side air passage 6 of the turbo fan 13 is further increased. Therefore, the speed distribution improving effect of the main plate 10 side main flow F ₁ described above becomes more effective.

(Modification 5)
In the case of this embodiment, the pair of left and right air passages 6 and 6 may each be formed with a scroll portion. In such a case, the length of the rear edge portion 12b of the blade 12 extended in the air blowing direction is appropriately set corresponding to the installation position of the scroll portion.

  When the air passages 6 and 6 have a scroll portion, when the trailing edge of each blade 12, 12... Approaches the scroll portion by a predetermined distance or more, due to the interference between the air flow and the scroll portion (solid wall), Discrete (rotation speed [rps] × number of blades [sheets] × n: n = natural number) interference sound (so-called NZ sound) is generated.

  Therefore, when there is a scroll portion in the air passages 6 and 6, the extension amount of the blade trailing edge portion 12b is extended in order not to make the distance between each blade 12, 12,... Is set in a range that does not generate the interference sound.

It is sectional drawing which shows the structure of the indoor unit for air conditioners which concerns on best embodiment of this invention. It is a perspective view of the heat exchanger part of the indoor unit. It is a perspective view of the turbo fan impeller part of the indoor unit. It is a front view of the turbofan impeller part. It is the perspective view seen from the rear part slanting upper part of the blade | wing part of the turbofan impeller. It is a front view (figure seen from the side plate side in the main plate direction) of the blade portion of the turbofan impeller. It is a figure which shows sectional drawing of the main plate side part of the blade | wing of the turbofan impeller compared with the conventional one. It is sectional drawing which shows the structure and effect | action of an air blowing part of the turbofan impeller. . It is sectional drawing which shows the structure and effect | action of the main part of the indoor unit of FIG. It is a figure which shows the air volume / rotational speed characteristic of the indoor unit of FIG. 1 in contrast with the conventional one. It is a figure which shows the air volume / ventilation sound characteristic of the indoor unit of FIG. 1 in contrast with the conventional one. It is explanatory drawing which shows the spectrum distribution of the ventilation sound of the indoor unit of FIG. 1 in contrast with the conventional one. It is sectional drawing which shows the effect | action of the blade | wing part of the turbofan impeller which concerns on the modification 1 of this Embodiment. It is sectional drawing which shows the structure and effect | action of the blade | wing part of the turbofan impeller which concerns on the modification 2 of this Embodiment. It is sectional drawing which shows the structure and effect | action of the blade | wing part of the turbofan impeller which concerns on the modification 3 of this Embodiment. It is sectional drawing which shows the structure of the indoor unit for air conditioners which concerns on the modification 4 of this Embodiment. It is sectional drawing which shows the structure and effect | action of the principal part of the air conditioner.

Explanation of symbols

  1 is an indoor unit, 2 is a back panel, 3 is a side panel, 4 is an intake / outlet panel, 6 is an air passage, 8 is a fan motor, 8a is a drive shaft, 9 is an air heat exchanger, 10 is a main plate, 11 is A side plate, 12 is a blade, 12a is a blade leading edge, 12b is a blade trailing edge, and 13 is a turbofan.

Claims (9)

  A thin indoor unit casing having a small depth dimension in the front-rear direction, an air inlet provided in the center of the front side of the indoor unit casing, and a pair of air outlets provided on the left and right of the front side of the indoor unit casing A pair of left and right air passages located inside the indoor unit casing and continuing from the air suction port to the pair of left and right air outlets; and the air suction port located upstream of each of the pair of left and right air passages And a pair of left and right heat exchangers provided on the downstream side of the pair of left and right air passages and corresponding to the pair of left and right air outlets. An indoor unit for an air conditioner, wherein the pair of left and right heat exchangers are configured such that an interval between the pair of left and right air passages extending from a central portion in the indoor unit casing to a left and right air outlet is an indoor unit casing Before On the other hand, the centrifugal blower is provided with an inclination so as to form a wide letter C on the back side and on the back side. A main plate supported and fixed at a predetermined interval; a ring-shaped side plate provided on the other end in the span direction of the plurality of blades; and blade driving means for rotating the plurality of blades via the main plate; And the main plate side is located on the back side of the indoor unit casing, the side plate side is located on the front side of the indoor unit casing, and the plurality of blades have radial lengths on the main plate side. Is formed longer than the radial length on the side plate side.   2. The air conditioner according to claim 1, wherein the main plate side radial length of the blade is longer than the side plate side by extending the rear edge of the blade longer in the air blowing direction. Indoor unit.   The main plate side radial length of the blade is formed longer than the side plate side by extending the rear edge of the blade longer in the air blowing direction as the distance increases according to the distance between the blade and the heat exchanger. The indoor unit for an air conditioner according to claim 2, wherein   4. The air conditioner according to claim 2, wherein the blade trailing edge extended long rearward in the air blowing direction is extended so as to gradually increase linearly from the side plate side to the main plate side. 5. Indoor unit.   4. The air conditioner according to claim 2, wherein the blade trailing edge extended long rearward in the air blowing direction is gradually extended in a curved shape from the side plate side to the main plate side. Indoor unit.   The trailing edge extended from the side plate side to the main plate side so as to gradually increase in a curved shape has one or more inflection points in the middle of the curved extension portion, thereby being located on the main plate side. The indoor unit for an air conditioner according to claim 5, wherein a bulging portion is formed.   The air conditioner according to claim 1, 2, 3, 4, 5 or 6, wherein a step portion extending a predetermined length forward in the air suction direction is provided in a main plate side portion of the blade leading edge portion. Indoor unit.   The pair of left and right air passages are each formed with a scroll portion, and the length of the blade trailing edge portion extended in the air blowing direction is set corresponding to the installation position of the scroll portion. The indoor unit for an air conditioner according to claim 1, 2, 3, 4, 5, 6 or 7.   9. The plurality of blades are three-dimensional blades extending in the axial direction while being twisted between the main plate and the side plate, respectively. Centrifugal blower.

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