WO2011114375A1

WO2011114375A1 - Cross-flow fan and air conditioner

Info

Publication number: WO2011114375A1
Application number: PCT/JP2010/001945
Authority: WO
Inventors: 池田尚史; 田所敬英; 山下哲央; 平川誠司; 代田光宏
Original assignee: 三菱電機株式会社
Priority date: 2010-03-18
Filing date: 2010-03-18
Publication date: 2011-09-22
Also published as: AU2010348684B2; CN102812253B; AU2010348684A1; CN102812253A; EP2549114B1; ES2690196T3; EP2549114A1; EP2549114A4

Abstract

A cross-flow fan comprises: blade wheel units (8d) provided with circular plate-like support plates (8b) having a rotation center located at the center section thereof, and also with blades (8c) which are arranged along the outer peripheries of the support plates (8b), extend in the direction of the rotation axis, and each have both ends supported by the support plates (8b); a blade wheel (8a) comprising the blade wheel units (8d) secured in the direction of the rotation axis; and grooves (14) which are provided in negative pressure surfaces (13a) of the blades (8c), the negative pressure surfaces (13a) being the rear surfaces of the blades (8c) relative to the rotational direction, and which extend in the direction of the rotation axis. The grooves (14) are separated from each other with predetermined intervals therebetween so that a flat section (M) is provided between adjacent grooves (14).

Description

Cross-flow fan and air conditioner

The present invention relates to a once-through fan used as a blowing means and an air conditioner equipped with the once-through fan.

As an example of a cross-flow fan mounted on a conventional air conditioner, there is a fan provided with a groove, a small depression, or a small protrusion along the rotation direction around the periphery of the impeller on the suction surface side of each blade. (For example, refer to Patent Document 1).

JP-A-3-210093

The example described in Patent Document 1 as an example of a conventional once-through fan is provided with grooves, small depressions, and small protrusions along the rotation direction around the periphery of the impeller on the suction surface side of each blade. The once-through fan is installed in the air passage formed by the inlet and outlet, and when the blades forming the once-through fan rotate and are located on the outlet side, separation occurs as the flow passing through the blade approaches the trailing edge. This separation causes pressure fluctuations that cause noise. Therefore, in Patent Document 1, pressure fluctuations that cause noise are absorbed by grooves, small depressions, and small protrusions provided on the suction surface of the blade, thereby reducing broadband noise and reducing noise. However, when the blade is rotated and positioned on the suction side, the flow passage direction of the blade is reversed as compared with the case where the blade is positioned on the outlet side. Therefore, the groove, small depression, and small projection become the leading edge of the flow, and a large flow velocity difference occurs in the longitudinal direction of the blade due to the concentration of the flow in the small groove, or flow separation and small protrusion on the side of the small depression The flow in the longitudinal direction of the blade is generated and the flow becomes unstable. On the contrary, there is a possibility that the pressure fluctuation occurs and the broadband noise is deteriorated.

In addition, when a cross-flow fan is installed in the air conditioner, the ventilation resistance increases due to dust adhesion to the filter arranged on the impeller suction side, and the angle of attack of the flow with respect to the blades changes, and it becomes easy to peel off. There were problems such as unstable flow. During cooling operation of the air conditioner, if the air flow becomes unstable and a reverse flow from the room to the fan occurs, the cold air flows into the impeller and forms condensation, and the floor is moistened by splashing condensed water to the outside. There was a possibility.

Usually, when manufacturing a blade, a thermoplastic resin such as AS is poured into a blade mold, and after cooling, it is released in the impeller rotating shaft direction to form a blade portion. However, in order to manufacture a blade having grooves, small depressions, or small protrusions extending in the blade rotation direction (direction orthogonal to the rotation axis) on the suction surface of the blade as in the configuration of Patent Document 1, in the direction of the rotation axis. Therefore, there is a problem in that it is impossible to release the mold, and it is necessary to release the mold in the direction perpendicular to the rotation axis, which complicates the manufacturing method and deteriorates the productivity.

The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a cross-flow fan that can achieve low noise and high efficiency.
Moreover, it aims at obtaining the air conditioner which can be quiet and can save energy.

A cross-flow fan according to the present invention includes a disc-shaped support plate having a center of rotation located at the center, a plurality of fans arranged along the outer periphery of the support plate, extending in the direction of the rotation axis, and supported at both ends by the support plate. An impeller having a plurality of blades, an impeller formed by fixing a plurality of impellers in the direction of the rotation axis, and a blade suction surface that is a rear surface with respect to the rotation direction of the blades. A plurality of concave grooves extending, and the grooves are provided separated by a predetermined interval so as to have a flat portion between adjacent grooves.

The cross-flow fan according to the present invention includes a disc-shaped support plate having a center of rotation located at the center, and is disposed along the outer periphery of the support plate and extends in the rotation axis direction, and both ends thereof are supported by the support plate. An impeller having a plurality of blades, an impeller formed by adhering a plurality of impellers in the direction of the rotation axis, and a motor shaft fixed to the support plate located at an end of the impeller. A fixed portion of a motor that rotationally drives the impeller, a fixed portion of the motor shaft located inside the impeller single unit, and a part of the interval between the blades of the impeller so that a fixing tool can be inserted into the fixed portion A widened opening, and at least a plurality of blades adjacent to the opening on the rotational direction side of the impeller and extending in the rotational axis direction on a blade suction surface that is a rear surface with respect to the rotational direction Specially provided with a concave groove It is an.

The cross-flow fan according to the present invention includes a disc-shaped support plate having a center of rotation located at the center, and is disposed along the outer periphery of the support plate and extends in the rotation axis direction, and both ends thereof are supported by the support plate. An impeller having a plurality of blades and an impeller formed by fixing a plurality of the impellers in the direction of the rotation axis, and rotation at a connection portion connected to the support plate at one end of the blade The cross-sectional shape perpendicular to the axis is made larger than the cross-sectional shape perpendicular to the rotation axis at the connecting portion connected to the support plate at the other end of the blade, and the rear surface is the rear surface with respect to the rotation direction of the blade. The blade suction surface is provided with a plurality of concave grooves extending in the rotation axis direction.
Moreover, the air conditioner which concerns on this invention mounts the said cross-flow fan.

According to the present invention, it is possible to obtain a cross-flow fan that can suppress separation on the suction surface side of the blade, stabilize the flow, and achieve low noise and high efficiency.
In addition, by installing this cross-flow fan in an air conditioner, an air conditioner that can be quiet and save energy can be obtained.

It is an external appearance perspective view which shows the air conditioner carrying the cross-flow fan which concerns on Embodiment 1 of this invention. FIG. 4 is a longitudinal sectional view taken along line QQ in FIG. 1 according to the first embodiment of the present invention. It is the schematic which shows the impeller of the crossflow fan which concerns on Embodiment 1 of this invention. FIG. 5 is a perspective view illustrating a state in which, for example, one wing is fixed to one ring according to the first embodiment of the present invention. FIG. 5 is an explanatory view showing, on an enlarged scale, the cross section along line PP in FIG. 4 according to the first embodiment of the present invention. It is explanatory drawing which concerns on Embodiment 1 of this invention and shows the shape of the groove | channel provided in the blade negative pressure surface in the cross section perpendicular | vertical to an impeller rotating shaft. It is explanatory drawing which concerns on Embodiment 1 of this invention and shows the shape of the groove | channel provided in the blade negative pressure surface in the cross section perpendicular | vertical to an impeller rotating shaft. FIG. 8 is an explanatory diagram showing the air flow when the blade 8c passes through the impeller suction region E1 according to the first embodiment of the present invention. It is explanatory drawing which concerns on Embodiment 1 of this invention and shows the flow of air when a wing | blade passes the impeller blowing area | region E2. It is a perspective view which shows the impeller of the once-through fan which concerns on Embodiment 2 of this invention. FIG. 11A is a perspective view partially showing a motor-side impeller, and FIG. 11B is an explanatory view seen from the side, according to Embodiment 2 of the present invention. FIGS. 12A and 12B are schematic views showing an impeller of a cross-flow fan according to Embodiment 3 of the present invention, FIG. 12A is a side view of the cross-flow fan, and FIG. 12B is a cross-sectional view taken along line SS in FIG. The figure is shown. It is sectional drawing which shows type | molds 17 and 18 regarding Embodiment 3 of this invention. FIG. 13 is a cross-sectional view taken along the line AA of one blade in FIG. 12 according to the third embodiment of the present invention. FIG. 13 is a cross-sectional view taken along the line BB of one blade in FIG. 12 according to the third embodiment of the present invention. FIG. 10 is a perspective view illustrating one blade according to another configuration example of the cross-flow fan according to the third embodiment of the present invention. FIG. 9 is an enlarged cross-sectional view showing a part of a cross section perpendicular to a rotation axis at a blade longitudinal tip portion of a blade according to Embodiment 3 of the present invention. It is a front view which shows another structural example of the crossflow fan which concerns on Embodiment 3 of this invention, and shows one blade. It is a front view which shows another structural example of the crossflow fan which concerns on Embodiment 3 of this invention, and shows one blade. It is a front view which shows another structural example of the crossflow fan which concerns on Embodiment 3 of this invention, and shows one blade. It is a front view which shows another structural example of the crossflow fan which concerns on Embodiment 3 of this invention, and shows one blade. It is a front view which shows another structural example of the crossflow fan which concerns on Embodiment 3 of this invention, and shows one blade.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view showing an air conditioner equipped with a cross-flow fan according to the present embodiment, and FIG. 2 is a longitudinal sectional view taken along line QQ in FIG. The flow of air is indicated by white arrows in FIG. 1 and indicated by dotted arrows in FIG.
As shown in FIG.1 and FIG.2, the air conditioner main body 1 is installed in the wall 11a of the room 11 to be air-conditioned. The air conditioner main body upper portion 1a is provided with a suction grill 2 that serves as a suction port for room air, an electric dust collector 6 that electrostatically collects dust and collects dust, and a mesh-like filter 5 that removes dust. Furthermore, the heat exchanger 7 having a configuration in which the pipe 7b passes through the plurality of aluminum fins 7a is arranged on the front side and the upper side of the impeller 8a so as to surround the impeller 8a. Moreover, the air conditioner main body front surface 1b is covered with the front panel, and the blower outlet 3 is opened on the lower side. The cross-flow fan 8 that is a blower has a stabilizer 9 that separates the suction side flow path E1 and the blowout side flow path E2 from the impeller 8a, and temporarily stores water droplets dripped from the heat exchanger 7. A spiral guide wall 10 is provided on the outlet side of the vehicle 8a in order to form the back surface of the outlet side flow path. Further, an up / down wind direction vane 4a and a left / right wind direction vane 4b are rotatably attached to the air outlet 3 to change the blowing direction into the room. In the figure, O indicates the rotation center of the impeller 8a, E1 is a suction region of the impeller 8a, and E2 is a blowout region of the impeller 8a. RO indicates the rotation direction of the impeller 8a.

In the air conditioner body 1 configured as described above, when the motor that rotates the impeller 8a is energized by the power supply board, the impeller 8a of the cross-flow fan 8 rotates in the RO direction. Then, the air in the room 11 is sucked in from the suction port 2 provided in the air conditioner main body upper portion 1a, dust is removed by the electric dust collector 6 and the filter 5, and then the air is heated and heated by the heat exchanger 7. Alternatively, it is cooled, cooled or dehumidified, and sucked into the impeller 8 a of the cross-flow fan 8. Thereafter, the flow blown out from the impeller 8 a is guided to the guide wall 10, travels to the blowout port 3, and is blown into the room 11 to be air-conditioned. At this time, the air flow is controlled in the vertical and horizontal directions by the vertical wind direction vanes 4a and the left and right wind direction vanes 4b, so that the entire room 11 is blown to suppress temperature unevenness.

FIG. 3 is a schematic view showing the impeller 8a of the cross-flow fan 8 according to the present embodiment, FIG. 3 (a) is a side view of the cross-flow fan 8, and FIG. 3 (b) is an N− line in FIG. 3 (a). N-line sectional view is shown, the lower half shows a state in which a plurality of wings on the other side can be seen, and the upper half shows one wing 8c. As shown in FIG. 3, the impeller 8a of the cross-flow fan 8 has a plurality of impellers 8d in the rotation axis direction AX. The impeller single unit 8d is constituted by a disc-shaped support plate whose center of rotation is located at the center, for example, a ring 8b, and a plurality of blades 8c arranged along the outer periphery of the ring 8b and extending in the rotation axis direction AX. Is done. The plurality of blades 8c are supported at both ends by the ring 8b. For example, a single impeller 8d formed of a thermoplastic resin such as AS resin or ABS resin is provided in a plurality of impellers 8d in the rotation axis direction AX, and the tip of the blade 8c is arranged next to each other by, for example, ultrasonic welding. Connected to the ring 8b. A fan shaft 8f is provided at the center of the ring 8b located at one end in the rotational axis direction AX, and a fan boss 8e is provided at the center of the ring 8b located at the other end. The fan boss 8e and the motor shaft 12a of the motor 12 are fixed with screws or the like. The ring 8b is a plate-like support plate having a circular outer shape, and the ring 8b positioned at both ends of the impeller 8a in the rotation axis direction is formed with a fan shaft 8f and a fan boss 8e at a central portion where the rotation axis is positioned. The ring 8b excluding both ends has a ring shape in which the central portion where the rotation axis is located is a space. In FIG. 3B, the alternate long and short dash line connects the motor shaft 12a and the fan shaft 8f and is a virtual rotation axis indicating the rotation center O, and indicates the rotation axis direction.

In the present embodiment, as shown in FIG. 3, a plurality of grooves 14 are formed between the blade outer peripheral end 15a and the blade inner peripheral end 15b on the blade suction surface 13a of the blade 8c. Here, the shape of the wing will be explained in detail. The surface that receives pressure during rotation on the surface of the blade 8c in the direction of rotation is referred to as blade pressure surface 13b, and the surface opposite to the blade pressure surface 13b that generates negative pressure during rotation is referred to as blade negative pressure surface 13a. FIG. 4 is a perspective view showing a state in which one blade 8c is fixed to, for example, one ring 8b, and FIG. 5 is an explanatory view showing an enlarged cross section along line PP in FIG. As shown in FIG. 4, the blade outer peripheral end 15a of the blade 8c is located on the outer peripheral side of the ring 8b, and the blade inner peripheral end 15b of the blade 8c is positioned on the inner peripheral side of the ring 8b. A substantially arc shape is formed between the end portion 15a and the blade inner peripheral side end portion 15b. In a cross section perpendicular to the rotation axis of the blade 8c, the warp line U, which is the thickness center line of the blade 8c when there is no groove 14, is connected to the blade outer end 15a and the blade inner end 15b of the blade 8c. The straight line is a chord line L, and the length of the chord line L is L1.

Further, as shown in FIG. 5, the blade 8c is compared with the blade thickness te1 at the arcuate blade outer peripheral end 15a and the blade thickness te2 (not shown) at the blade inner peripheral end 15b. The wing thickness te3 of the central portion in the chord line L direction is configured to be thicker than the wing thickness te1 and the wing thickness te2. That is, the blade thickness maximum portion 15c having the maximum thickness tmax is between the blade outer peripheral end portion 15a and the blade inner peripheral end portion 15b in the chord line L direction of the blade 8c, and from the blade outer peripheral end portion 15a. The blade thickness increases smoothly from the blade thickness maximum portion 15c, and the blade thickness decreases smoothly from the blade thickness maximum portion 15c to the blade inner peripheral side end portion 15b.

Furthermore, the blade suction surface 13a is provided with a plurality of grooves 14 extending in the rotation axis direction AX, that is, in the blade longitudinal direction. The concave groove 14 includes a groove bottom portion 14b and groove side portions 14a connected to both ends of the groove bottom portion 14b. 6 and 7 are explanatory views showing, in an enlarged manner, the shape of the groove 14 provided in the blade suction surface 13a in a cross section orthogonal to the impeller rotational axis AX. The groove side part 14a is inclined so that the groove width gradually increases from the groove bottom part 14b toward the blade suction surface 13a. Moreover, it is rounded in the vicinity where the groove side portion 14a and the blade negative pressure surface 13a are connected, and is formed to have, for example, a substantially arc shape. Furthermore, the groove side part 14a and the groove bottom part 14b are rounded in the vicinity where they are connected to form a substantially arc shape. Here, the groove depth of the groove 14 is h, the groove width is g, the flat part between the adjacent blades 14 of the blade suction surface 13a is M, and the flat part length is ML. A dotted line i indicates the blade suction surface 13a when the groove 14 is not formed. The groove width g and the flat portion length ML are set to a length between the virtual intersection points 14p by setting a virtual intersection point 14p obtained by extending an extension line of the blade suction surface 13a and the groove side portion 14a.

Further, as shown in FIGS. 5 and 6, the dotted line K is based on the blade pressure surface 13b, and the blade thickness te1 at the blade outer peripheral end 15a or the blade thickness te2 at the blade inner peripheral end 15b, etc. As a thick line, the groove bottom part 14b of the groove 14 is formed so as to be closer to the blade negative pressure surface 13a side than the constant thickness line K. In other words, the groove 14 is provided on the blade suction surface 13a side of the constant thickness line K. In addition, the groove 14 is formed so that the groove depth h <the flat portion length ML is satisfied as the relationship between the groove depth h of the groove 14 and the flat portion length ML of the flat portion M. Further, the groove depth hc in the central portion 15c between the blade outer peripheral end portion 15a and the blade inner peripheral end portion 15b is greater than the groove depth ht in the vicinity of the blade outer peripheral end portion 15a and the blade inner peripheral end portion 15b. It is also bigger.

In the impeller 8a having the groove 14 in the blade 8c, the air flow of the blade negative pressure surface 13a and the blade pressure surface 13b of the single blade 8c when the blade 8c passes through the impeller suction region E1. As shown in FIG. FIG. 8 is an explanatory view showing the air flow when the blade 8c passes through the impeller suction region E1.
When the blade 8c passes through the impeller suction region E1, the suction air passes from the blade outer peripheral end 15a to the blade negative pressure surface 13a. Here, since the groove 14 is provided on the blade negative pressure surface 13 a, the inside of the groove 14 becomes negative pressure, and a flow having a directional component toward the inside of the groove 14 as indicated by an arrow 20. For this reason, the air flow is attracted to the blade negative pressure surface 13a even if the blade negative pressure surface 13a is likely to be separated toward the downstream side. And since it draws to the blade negative pressure surface 13a over the blade inner peripheral end 15b on the downstream side, the separation vortex when the flow is separated at the blade inner peripheral end 15b can be reduced.

FIG. 9 is an explanatory view showing the air flow of the blade negative pressure surface 13a and the blade pressure surface 13b of one blade 8c when the blade 8c passes through the impeller blowing region E2. When the blade 8c passes through the impeller blowing region E2, the intake air passes from the blade inner peripheral end 15b to the blade negative pressure surface 13a. Here, since the groove 14 is provided on the blade negative pressure surface 13 a, the inside of the groove 14 becomes negative pressure, and the flow has a directional component toward the inside of the groove 14 as indicated by an arrow 21. For this reason, the air flow is attracted to the blade negative pressure surface 13a even if the blade negative pressure surface 13a is likely to be separated toward the downstream side. And since it draws toward the blade negative pressure surface 13a over the downstream blade outer peripheral end portion 15a, it is possible to reduce the separation vortex when the flow is separated at the blade outer peripheral end portion 15a.

Thus, the groove 14 provided on the blade suction surface 13a can suppress separation of the air flow at the blade suction surface 13a in both the suction region E1 and the blowout region E2, and as a result, the blowout from the blade outer peripheral end 15a. It is possible to reduce the separation vortex when the flow separates into the region E2.

Further, since the groove 14 is formed to extend in the rotation axis direction (blade longitudinal direction), even if a wind speed difference occurs in the flow passing in the blade longitudinal direction, the pulling effect by the groove 14 can be obtained. For this reason, peeling can be suppressed as a whole.
Furthermore, since the separation can be suppressed, the effective area of the inter-blade flow path can be increased and the driving torque of the motor can be reduced. As a result, an efficient once-through fan is obtained.

The plurality of grooves 14 formed on the blade suction surface 13a of the cross-flow fan are provided at a predetermined interval ML so as to have a flat portion M between the adjacent grooves 14 in a cross section perpendicular to the rotation axis. ing. When the groove 14 is continuously formed without a gap in the chord line L direction, even if a negative pressure is generated in the groove 14, the flow cannot be reattached to the blade negative pressure surface 13a and becomes unstable. That is, the air flow flowing along the blade negative pressure surface 13 a tries to reattach to the blade negative pressure surface 13 a connected to the groove 14 after getting over the groove 14 due to the drawing effect in the groove 14. Therefore, by forming the flat portion M having the length ML between the adjacent grooves 14, it is possible to stably reattach by taking a sufficient length when reattaching. As described above, after the pulling effect in the groove 14, the flow is always stabilized by reattaching to the suction surface and repeating the pulling effect again. In particular, there is an effect that the pulling effect by the groove 14 can be sufficiently exhibited. As a result, the cross-flow fan can achieve low noise and high efficiency, and can prevent separation against changes in ventilation resistance, and can prevent backflow to the fan due to instability of the blowout flow.

Further, in the cross section perpendicular to the rotation axis, the connecting portions of the groove side portions 14a of the plurality of grooves 14 formed on the blade suction surface 13a and the blade suction surface 13a are rounded, for example, have a substantially arc shape. Formed. For this reason, when the flow is attracted by the groove 14 and flows to the blade blade pressure surface 13a on the downstream side, it is possible to prevent the pressure fluctuation caused by hitting the corner. Therefore, a cross-flow fan that can further reduce noise and increase efficiency can be obtained. Further, two corners connecting the two groove side portions 14a and the blade suction surface 13a to one groove 14 are both substantially arc-shaped. Thereby, even if the wing | blade 8c reverses the direction of a flow in the suction area | region E1 and the blowing area | region E2, peeling can be suppressed in both area | regions E1 and E2.

In addition, in the cross section perpendicular to the rotation axis, the groove bottom portion 14b has a rounded shape, and the groove side portion 14a continuous to the groove bottom portion 14b has a shape extending toward the blade suction surface 13a. Since the groove bottom portion 14b has, for example, an arc shape, the flow inside the groove can be smoothly circulated and stabilized. Further, the groove side portion 14a has an inclination so as to expand toward the blade suction surface 13a, thereby effectively guiding the flow into the groove 14 to obtain a drawing effect. Accordingly, it is possible to obtain a cross-flow fan that can be made more efficient with lower noise.

Further, the groove bottom portion 14b of the groove 14 is formed so as to be closer to the blade suction surface 13a side than the contour line K. For example, when the blade thickness in the vicinity of the blade outer peripheral end portion 15a or the blade inner peripheral end portion 15b is about 0.5 mm and the blade thickness at the blade central portion 15c is about 1.5 mm, the iso-thick line K indicates the blade pressure surface. From 13b to about 0.5 mm. Since the groove 14 is formed in the blade suction surface 13a from the blade thickness line K, the groove depth hc at the blade center portion 15c is configured to be 1.0 mm or less. For example, the groove depth h is set to about 0.25 mm, and the groove 14 is provided in the blade negative pressure surface 13a in a portion where the blade thickness is larger than about 0.75 mm in the vicinity of the blade outer peripheral end portion 15a or the blade inner peripheral end portion 15b. With such a configuration, it is possible to obtain the pulling effect by the groove 14, and even if the groove 14 is formed, the thickness of the blade 8c can be secured and the strength can be improved.

Further, the groove 14 is formed so as to satisfy the groove depth h <the flat portion length ML. That is, the plurality of grooves 14 formed on the blade suction surface 13a of the cross-flow fan are formed with a cross section perpendicular to the rotation axis and at least a predetermined interval ML in the chord line direction. As described above, the function and effect of the flat portion M have been described. By making the flat portion length ML larger than the groove depth h, the flat portion M can ensure re-attachment after the flow has passed over the groove 14 and attracted. By repeating the effect and reattachment, the flow is always stabilized without peeling from the blade suction surface 13a. For this reason, a cross-flow fan that can achieve low noise and high efficiency can be obtained.

Further, although the groove 14 is provided on the entire surface of the blade negative pressure surface 13a from the blade outer peripheral side end portion 15a to the blade inner peripheral side end portion 15b, it is not limited to this. What is necessary is just to provide in the at least one edge part vicinity of the blade outer peripheral side edge part 15a and the blade inner peripheral side edge part 15b. For example, a configuration in which several, for example, two grooves 14 are provided in the vicinity of the blade outer peripheral end 15a, and several, for example, two grooves 14, in the vicinity of the blade inner peripheral end 15b may be provided. Further, only a few, for example, two grooves 14 may be provided in the vicinity of the blade outer peripheral end 15a. Conversely, a few, for example, two grooves 14 are provided in the vicinity of the blade inner peripheral end 15b. Such a configuration may be used. By providing at least the blade outer peripheral side 15a upstream in the suction region E1 and the blade inner peripheral side 15b upstream in the blowout region E2, separation of the air flow can be effectively reduced by the grooves 14. .

When the flow is easily separated in the suction region E1 due to the configuration of the device in which the cross-flow fan 8 is mounted, it is effective to provide the groove 14 in the vicinity of the blade outer peripheral end 15a that is the upstream side of the flow in the suction region E1. It is. Further, in the case where the flow is easily separated in the blowing region E2, it is effective to provide the groove 14 in the vicinity of the blade inner peripheral end portion 15b which is the upstream side of the flow in the blowing region E2.
However, as shown in FIG. 8 and FIG. 9, if the groove 14 is provided on the entire surface from the blade outer peripheral end 15 a to the blade inner peripheral end 15 b of the blade negative pressure surface 13 a in a cross section perpendicular to the rotation axis, the blade This is more effective because it can be prevented where peeling occurs on the negative pressure surface 13a.

In the above description, the groove 14 extending in the direction of the rotation axis of the blade suction surface 13a of the blade 8c is a long groove 14 extending from one end portion to the other end portion of the blade 8c. For example, if it is provided in at least one part of the central part, one end part, and the other end part in the blade longitudinal direction, the effect is obtained. Further, the plurality of grooves 14 need not have the same length. Moreover, the some groove | channel 14 may be arrange | positioned irregularly. That is, the start position and the end position of the groove 14 may be variously changed by the plurality of grooves 14 in the blade longitudinal direction of the blade 8 c.
Further, in one groove 14, the groove depth h, the flat part length ML, and the groove width g may not be the same. For example, the groove width g may be changed gradually or stepwise so that the groove width g is larger at one end in the blade longitudinal direction and smaller at the other end.

By not making the uniform groove 14 in the blade longitudinal direction, but making it non-uniform, the cross section perpendicular to the rotation axis changes at the position in the blade longitudinal direction. That is, in the case of drifting and flowing into the blade suction surface 13a, the number of grooves 14 changes in the direction of the chord line L. Even if minute separation occurs in the blade longitudinal direction, it is diffused by being influenced by the flow in the blade longitudinal direction in the vicinity thereof. And the wind speed distribution is made uniform. As a result, noise is reduced.

Further, as shown in FIG. 5, in the direction of the chord line L, the groove depth hc in the vicinity of the center portion of the blade chord between the blade outer peripheral end portion 15a and the blade inner peripheral end portion 15b of the blade 8c It is formed to be larger than the groove depth ht on the end portion 15a and the blade inner peripheral side end portion 15b side. For this reason, the drawing effect by the groove 14 can be obtained, and the blade thickness of the blade 8c can be prevented from becoming extremely thin, so that deterioration of the hot water around the molding and insufficient strength at the time of assembly can be prevented, and productivity can be improved. it can.

In the shape of the blade 8c, when the blade thickness between the blade pressure surface 13a and the blade suction surface 13b is substantially equal, the flow path gradually narrows from the blade inner peripheral end 15b to the blade outer peripheral end 15a. In this case, especially when the air flow flows from the outer peripheral side to the inner peripheral side in the suction region, the distance between the blades becomes wider on the inner peripheral side, and the flow becomes unstable. Can be suppressed. On the other hand, in the blade shape as shown in FIG. 5, the blade negative pressure surface 13a has a smaller arc radius on the blade surface and a larger curvature than the blade pressure surface 13b. That is, the blade thickness at the central portion 15c in the chord line L direction is larger than the blade thickness at the blade inner peripheral end portions 15a and 15b. In such a shape, when the flow path distance between the adjacent blades 8c is viewed, the change from the blade inner peripheral side end portion 15b to the blade outer peripheral side end portion 15a is small, and the flow is likely to be stable while passing through the blade. Therefore, by providing a groove 14 as in the present embodiment on the blade suction surface 13a, the development of a minute boundary layer is suppressed, the air flow between the blades is made smooth, and the flow between the blades is caused by turbulent flow. It is possible to prevent the road from becoming narrow.

Further, in the present embodiment, the plurality of grooves 14 are arranged in parallel substantially in the blade longitudinal direction, and are formed substantially parallel to the blade outer peripheral end 15a and the blade inner peripheral end 15b in the blade longitudinal direction. did. If a plurality of grooves 14 are formed in a cross section perpendicular to the rotation axis, a pulling effect can be obtained, so that the blade outer circumferential end 15a and the blade inner circumferential end 15b are slightly inclined in the longitudinal direction of the blade. However, the same effect can be obtained. For example, the plurality of grooves 14 arranged side by side may be formed by twisting with respect to the rotation axis so as to advance or retreat in the rotation direction of the impeller 8a.

As described above, the cross-flow fan according to the present embodiment is arranged along the outer periphery of the disc-shaped support plate 8b whose center of rotation is located at the center and the support plate 8b, and extends in the direction of the rotation axis and has both ends thereof. A single impeller having a plurality of blades 8c supported by the support plate 8b, an impeller 8a formed by fixing a plurality of single impellers 8d in the direction of the rotation axis, and a rear surface with respect to the rotational direction of the blades 8c; A plurality of concave grooves 14 provided on the blade suction surface 13a and extending in the direction of the rotation axis, and the grooves 14 are provided separated by a predetermined interval so as to have a flat portion M between adjacent grooves 14. By generating negative pressure in the groove 14, the air flow is attracted to the blade negative pressure surface 13 a, and the flow over the groove 14 is reattached so that it is difficult to separate from the blade negative pressure surface 13 a. it can. Then, the development and separation of the boundary layer on the suction surface side of the blade can be suppressed, the effective area of the inter-blade channel can be increased, and the driving torque of the motor can be reduced. For this reason, a cross-flow fan that can achieve low noise and high efficiency can be obtained.

Further, the cross-flow fan 8 is disposed between the suction-side flow path E1 and the blow-off-side flow path E2, and the heat exchanger 7 is disposed in the suction-side flow path E1 so as to surround the impeller 8a. In the air conditioner that exchanges heat with the sucked air blown by the heat exchanger 7 and blows out into the room through the blow-out side flow path E2, by mounting the cross-flow fan 8 described in the present embodiment, And an energy-saving air conditioner can be obtained. Further, even if the ventilation resistance increases on the upstream side, it is difficult to separate, and further, the separation vortex when the flow is separated from the blade 8c by the groove 14 can be reduced, and a stable flow is blown out. Sometimes, back flow from the room to the cross-flow fan 8 can be prevented, and the impeller 8a can be prevented from dewing and releasing condensed water to the outside.

Embodiment 2. FIG.
10 is a perspective view showing an impeller 8a of a once-through fan according to Embodiment 2 of the present invention, FIG. 11 is a view showing a motor side portion of the impeller of the once-through fan, and FIG. The perspective view which shows the impeller 8a of a side partially, FIG.11 (b) is explanatory drawing seen from the side surface. FIG. 11B shows a part of the side surface of the ring 8b closest to the motor by cutting away, and the notched part shows the blade 8c together with the adjacent ring 8b. In each figure, the same reference numerals as those in Embodiment 1 denote the same or corresponding parts.

In the impeller 8a in the present embodiment, the fan boss 8e fixed to the motor shaft 12a protrudes to the inner side of the impeller unit 8d located at the end of the impeller 8a. As shown in FIG. 10, the impeller 8a of the cross-flow fan 8 has a plurality of impellers 8d in the rotation axis direction AX. The impeller unit 8d is arranged along the outer periphery of a disc-shaped support plate, in this case, for example, the ring 8b and the ring 8b, in which the center of rotation is located at the center, extends in the direction of the rotation axis, and is supported by the ring 8b at both ends. A plurality of wings 8c. The impeller single unit 8d is formed of, for example, a thermoplastic resin such as AS resin or ABS resin, and a plurality of, for example, five impeller units 8d in the rotational axis direction AX are formed in the rotational axis direction AX by, for example, ultrasonic welding. Adhering to form the impeller 8a. A fan boss 8e is provided at the center of the ring 8b at the end on the motor side, and the fan boss 8e and the motor shaft 12a of the motor 12 (shown in FIG. 3) are fixed at the fixing portion 16 with screws or the like. By fixing the rotation shaft of the motor shaft 12a and the impeller 8a by the fixing portion 16, the impeller 8a is rotationally driven by the rotation of the motor 12.

In the present embodiment, a fan boss 8e that fixes the impeller 8a and the motor 12 protrudes into the impeller, and a fixing portion that is fixed to the motor shaft 12a is formed inside the impeller unit 8da. By comprising in this way, since the full length of the impeller 8a can be lengthened only the length of the fan boss | hub 8e, maintaining the width of an air conditioner, ventilation characteristics can be improved. In the impeller single unit 8da positioned at the end portion on the motor 12 side configured as described above, the blade 8c is partially inserted so that a fixing tool can be inserted when the fan boss 8e and the motor shaft 12a are fixed by the screw holes 16. It is the structure which has the opening part C without providing. This is indicated by a circle C in FIG. For example, in the other impeller unit 8d, the blades 8c are provided evenly around the rotation shaft which is a shaft at 360 degrees, but in the impeller unit 8da, a predetermined number of blades 8c facing the screw holes 16 are provided. For example, the screw hole 16 can be seen from the opening C without being provided with only one toothless here.

In the present embodiment, in the case of the impeller 8a having a configuration in which the blades of the single impeller 8da are partially missing and have the opening C, the blade negative pressure surface 13a of the blade 8ca advanced in the rotational direction at least from the opening C. The groove 14 shown in the first embodiment is provided.

Since the distance between the blade 8ca and the blade 8cb adjacent to each other in the opening C is wider than that between the other blades, more air flows than the flow path formed between the other blades, so that the air easily peels off. If it peels in the wide flow path made in the opening C, an abnormal sound such as fluttering may occur. On the other hand, in the present embodiment, a plurality of grooves 14 extending in the longitudinal direction of the blade 8c are formed on at least the blade suction surface 13a of the first blade 8ca on the downstream side in the rotation direction of the blade 8c in the space C. As described in the first embodiment, as shown in FIGS. 8 and 9, since the flow is attracted by the groove 14 and the separation is suppressed, the noise due to the separation can be reduced compared with the case where the groove 14 is not formed, and it is quiet. Can be obtained.

The configuration of the groove 14 is the same as that of the first embodiment. If the groove 14 shown in the first embodiment is provided at least on the blade suction surface 13a of the blade 8ca advanced in the rotation direction from the opening C, the air flow flowing between the blades is effective. Furthermore, by providing the groove 14 on the blade suction surface 13a of the other blade 8c, it is possible to further suppress separation between the blades as the entire impeller. Since the separation can be suppressed, the effective area of the flow path between the blades can be increased and the driving torque of the motor can be reduced.

Further, not only the blade suction surface 13a of the blade 8ca advanced in the rotation direction from the opening C, but also a groove formed in the plurality of blades 8c in the portion advanced in the rotation direction from the opening C as shown in the region D. If 14 is provided, it is more effective. Further, it is more effective to provide the groove 14 on the blade suction surface 13a of the plurality of blades 8c including the blade 8cb in the counter-rotating direction with respect to the opening C.

In addition, in FIG. 11, although it was set as the structure which does not provide one blade 8c so that a fixing tool can be inserted in the fixing | fixed part 16, it does not restrict to this. For example, the impeller single unit 8d may be provided with a plurality of blades 8c at unequal pitches rather than at equal intervals. In this case, if the fixing portion 16 is configured to face a portion having a wide interval, the fixing tool can be inserted into the fixing portion 16. As described above, even when the opening C is formed so that the interval between the blades 8c is partially widened so that the fixing tool 16 can be inserted into the fixing portion 16, the opening is at least on the rotational direction RO side of the impeller 8a. A plurality of concave grooves 14 extending in the rotation axis direction AX may be provided on the blade suction surface 13a which is the rear surface of the blade 8c adjacent to the portion C with respect to the rotation direction RO.

As described above, the disk-shaped support plate 8b whose center of rotation is located at the center, and the plurality of support plates 8b arranged along the outer periphery of the support plate 8b and extending in the rotation axis direction AX and supported at both ends by the support plate 8b. The motor shaft 12a is fixed to an impeller 8d having blades 8c, an impeller 8a formed by fixing a plurality of impellers 8d in the rotation axis direction AX, and a support plate 8b positioned at an end of the impeller 8a. The motor 12 for rotationally driving the impeller 8a, the fixed portion 16 of the motor shaft 12a located inside the impeller single unit 8d, and the blades 8c of the impeller single unit 8d so that a fixing tool can be inserted into the fixed unit 16. And a blade suction surface 13a which is a rear surface of the blade 8ca adjacent to the opening C on the rotation direction RO side of the impeller 8a at the rear side with respect to the rotation direction RO. Rotation axis direction AX By building provided with a plurality of concave grooves 14, peeled from the wing negative pressure surface 13a is suppressed. For this reason, a stable flow can be obtained and noise can be reduced.

Further, as described in the first embodiment, the grooves 14 may be provided so as to be separated from each other by a predetermined interval so as to have a flat portion M between adjacent grooves, particularly in a cross section perpendicular to the rotation axis. By comprising in this way, since the fixing | fixed part 16 is visible, it is easy to manufacture. Even if there is a partial opening C between the blades, the flow can be stabilized by the pulling effect by the groove 14 and the reattachment effect by the flat portion M, noise can be reduced, and an efficient once-through fan can be obtained.
In addition, by installing a cross-flow fan, a quiet and high-quality air conditioner without any harshness can be obtained.

Here, a configuration is described in which separation is suppressed in consideration of the flow in the part where the interval between adjacent blades is wide due to the convenience of the fixing part in the assembly process. However, the present invention is not limited to this, and even when a portion where the interval between adjacent blades is increased for other reasons is formed on the blade suction surface 13a of the blade 8c on the rotation direction side of at least the portion where the interval is wide. A plurality of grooves 14 extending in the rotation axis direction AX may be provided.

Embodiment 3 FIG.
Hereinafter, Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 12 is a schematic view showing the impeller 8a of the cross-flow fan 8 according to the present embodiment, FIG. 12 (a) is a side view of the cross-flow fan 8, and FIG. 12 (b) is a view of FIG. A sectional view of line S is shown. In each impeller 8d, the lower half shows a state where a plurality of wings on the other side are visible, and the upper half shows one wing 8c. In the figure, the same reference numerals as those in the first and second embodiments indicate the same or corresponding parts. Also in FIG. 12B, the alternate long and short dash line is a virtual rotation axis that connects the motor shaft 12a and the fan shaft 8f and indicates the rotation center O. As shown in FIG. 12, the impeller 8a of the cross-flow fan 8 has a plurality of impellers 8d in the rotation axis direction AX. The impeller unit 8d is arranged along the outer periphery of a disk-shaped support plate, in this case, for example, the ring 8b and the ring 8b, in which the center of rotation is located at the center, extends in the direction of the rotation axis, and is supported by the ring 8b at both ends. A plurality of wings 8c. The blade 8c in the present embodiment has a cross-sectional shape perpendicular to the rotation axis at the blade root (right side in FIG. 12 (b)) which is a connecting portion connected to the ring 8b at one end in the impeller 8d. It is the largest and formed so that the sectional shape gradually becomes smaller. Then, at the other end of the blade 8c, the cross-sectional shape perpendicular to the rotation axis is minimized at the front end in the blade longitudinal direction (the left side in FIG. 12B) which is a connection portion fixed to the adjacent impeller 8d. Such a tapered shape. That is, in the cross section perpendicular to the rotation axis, the blade thickness of the blade 8c formed by the blade suction surface 13a and the blade pressure surface 13b, and the length of the straight line connecting the blade outer peripheral end 15a and the blade inner peripheral end 15b. The chord line length L1, which is the height, is made to be a shape that decreases from the blade root toward the tip in the blade longitudinal direction. For this reason, in the cross section shown in FIG. 12B, both the blade outer peripheral end 15a and the blade inner peripheral end 15b are inclined inward of the blade 8c from the blade root toward the blade longitudinal tip. It becomes a shape. Also in the present embodiment, a plurality of concave grooves 14 extending in the rotation axis direction AX are provided on the blade suction surface 13a which is the rear surface with respect to the rotation direction of the blade 8c.

In the manufacturing process, the impeller 8d is molded with a thermoplastic resin such as an AS resin or an ABS resin. In the impeller 8a, the plurality of blades 8c are fixed between the two rings 8b, and are formed integrally with one of the rings 8b, for example, the motor-side ring 8b, to form the impeller 8d. The state of mold release of this resin molding is shown in FIG. FIG. 13 is a cross-sectional view showing the molds 17 and 18 and shows a state in which the blades 8c are formed one by one up and down, but actually, a plurality of blades 8c are arranged in a ring shape inside the outer periphery of the ring 8b. To be molded. In resin molding, molds 17 and 18 are formed in a concavo-convex shape in the shape of a plurality of blades 8c, resin is injected into the mold at high pressure, and after cooling, the mold 18 is moved in the direction of the arrow. Thus, an impeller single body 8d formed of resin is obtained.

When the mold is released in the rotation axis direction AX as indicated by the arrow, the shape of the impeller 8d needs to be a shape that can be released in the rotation axis direction AX. For this reason, the blade 8c has the largest cross-sectional shape at the blade root 8c1, which is the portion of the blade 8c continuous with the ring 8b, and the cross-sectional shape at the blade longitudinal tip 8c2 is small in the impeller 8d. Form. By making such a cross-sectional shape of the blade 8c, mold release during resin molding is performed smoothly. Here, for example, from the blade root 8c1 of the blade 8c toward the blade longitudinal direction tip 8c2, the cross-sectional shape of the blade is gradually reduced to form a tapered blade 8c. The blade outer peripheral side end portion 15a and the blade inner peripheral side end portion 15b are inclined on the inner side of the blade 8c so as to have an angle of, for example, several degrees. For this reason, when the mold 18 is slightly moved at the time of mold release, there is a space between the mold 18 and the molded impeller unit 8d on the entire surface of the blade 8c, so that the mold release is performed easily and smoothly. .

Then, if the blade longitudinal tip 8c2 of the resin-shaped tapered impeller 8d is fixed to the adjacent ring 8b by, for example, ultrasonic welding or the like, the impeller 8d is fixed in the rotational axis direction AX. Thus, the impeller 8a is formed.

Also in the present embodiment, the same groove 14 as in the first embodiment is provided on the blade suction surface 13a of the blade 8c. In other words, the blade suction surface 13a of the blade 8c is provided with a plurality of concave grooves 14 extending in the blade longitudinal direction which is the rotation axis direction AX. In a cross section perpendicular to the rotation axis, for example, a plurality of grooves 14 arranged evenly between the blade outer peripheral end portion 15a and the blade inner peripheral end portion 15b include a groove bottom portion 14b and two opposing groove side portions 14a. The groove bottom portion 14b has a rounded shape, and here has a substantially arc shape. The groove side part 14a that continues to the groove bottom part 14b has a shape that expands toward the blade suction surface 13a, and the connecting portion between the groove side part 14a and the blade suction surface 13 also has a round shape. The groove 14 extending in the rotational axis direction AX has a shape with irregularities in the circumferential direction of the impeller 8a and no irregularities in the rotational axis direction AX. For this reason, it is a shape suitable for shape | molding the impeller single-piece | unit 8d by resin shaping | molding which molds in the rotating shaft direction AX shown in FIG.

Furthermore, the shape of the wing will be explained in detail. FIG. 14 is a cross-sectional view taken along the line AA of one blade of FIG. 12, and shows a cross section of the blade longitudinal tip 8c2 of the blade 8c. FIG. 15 is a BB cross-sectional view of one blade of FIG. 12, showing a cross section of the blade root portion 8c1 of the blade 8c. As shown in FIGS. 14 and 15, in the cross section perpendicular to the rotation axis of the once-through fan, the shape of the blade 8c is the same in any cross section, and the size is the largest at the blade root portion 8c1, and the tip portion in the blade longitudinal direction. It becomes the smallest at 8c2.

In FIG. 14 showing the cross section of the blade longitudinal tip 8c2, the chord line length is L12, the groove depth is h2, the groove width is g2, the inscribed circle of the blade pressure surface 13b and the blade negative pressure surface 13a of the blade 8c. The maximum thickness of the blade thickness, which is the diameter, is tmax2. Similarly, in FIG. 15 showing a cross section of the blade root 8c1, the chord line length is L11, the groove depth is h1, the groove width is g1, and the maximum thickness is tmax1. Here, the definitions of the groove width g and the groove depth h are the same as those shown in FIG. 7 of the first embodiment. In the blade 8c of the present embodiment, the chord line length L1 and the maximum thickness tmax are smoothly reduced from the blade root 8c1 toward the blade longitudinal tip 8c2 by tmax1> tmax2 and L11> L12. It has a tapered shape. Regarding the groove 14, in the configuration example shown in FIG. 12, a plurality of grooves 14 having the same shape are provided on the blade negative pressure surface 13 a with h 1 = h 2 and g 1 = g 2.

As in the first embodiment, when the blade 8c passes through the suction region E1, the suction air passes from the blade outer peripheral end 15a to the blade negative pressure surface 13a. Here, since the plurality of grooves 14 extending in the blade longitudinal direction are formed in the blade negative pressure surface 13a, the air flow when the intake air passes through the blade negative pressure surface 13a is as shown in FIG. That is, the inside of the groove 14 has a negative pressure, and the flow has a directional component toward the inside of the groove 14 as indicated by an arrow 20. For this reason, even if it is peeled off at the blade outer peripheral end portion 15a, it is attracted to the blade negative pressure surface 13a, and further toward the downstream blade inner peripheral end portion 15b, it is also attracted to the blade negative pressure surface 13a. The separation vortex when the flow is separated can be reduced.

Further, as shown in FIG. 9, when the blade 8c passes through the blowing region E2, the intake air passes from the blade inner peripheral side end portion 15b to the blade negative pressure surface 13a. Here, since the groove 14 is provided on the blade negative pressure surface 13 a, the inside of the groove 14 becomes negative pressure, and the flow has a directional component toward the inside of the groove 14 as indicated by an arrow 21. For this reason, the air flow is attracted to the blade negative pressure surface 13a even if the blade negative pressure surface 13a is likely to be separated toward the downstream side. And since it draws toward the blade negative pressure surface 13a over the downstream blade outer peripheral end portion 15a, it is possible to reduce the separation vortex when the flow is separated at the blade outer peripheral end portion 15a.

Further, since the groove 14 is formed so as to extend in the rotation axis direction AX, the pulling effect by the groove 14 can be obtained even if a wind speed difference occurs in the blade longitudinal direction. For this reason, peeling can be suppressed as a whole.
Furthermore, since the separation can be suppressed, the effective area of the inter-blade flow path can be increased and the driving torque of the motor can be reduced. As a result, an efficient once-through fan is obtained.

Further, similarly to FIG. 7 in the first embodiment, the plurality of grooves 14 formed in the blade suction surface 13a of the cross-flow fan have a flat portion M between the adjacent grooves 14 in a cross section perpendicular to the rotation axis. As described above, the predetermined interval ML is provided apart. As described above, the flat portion M having the length ML is formed between the adjacent grooves 14, so that the reattachment can be stably performed by taking a sufficient length for the reattachment. After the attracting effect in the groove 14, the flow is always stabilized by reattaching to the negative pressure surface 13a and repeating the attracting effect again. In particular, there is an effect that the pulling effect by the groove 14 can be effectively exhibited. As a result, the cross-flow fan can achieve low noise and high efficiency, and can prevent separation against changes in ventilation resistance, and can prevent backflow to the fan due to instability of the blowout flow.

Further, as in the first embodiment, in the cross section perpendicular to the rotation axis, the connecting portions of the groove side portions 14a of the plurality of grooves 14 formed on the blade suction surface 13a and the blade suction surface 13a are rounded. For example, it formed so that it might become a substantially circular arc shape. For this reason, when the flow is attracted by the groove 14 and flows to the blade blade pressure surface 13a on the downstream side, it is possible to prevent the pressure fluctuation caused by hitting the corner. Therefore, a cross-flow fan that can further reduce noise and increase efficiency can be obtained. Further, two corners connecting the two groove side portions 14a and the blade suction surface 13a to one groove 14 are both substantially arc-shaped. Thereby, even if the wing | blade 8c reverses the direction of a flow in the suction area | region E1 and the blowing area | region E2, peeling can be suppressed in both area | regions E1 and E2.

Similarly to the first embodiment, the groove bottom portion 14b has a rounded shape in a cross section perpendicular to the rotation axis, and the groove side portion 14a continuous to the groove bottom portion 14b extends toward the blade negative pressure surface 13a. Shaped. Since the groove bottom portion 14b has, for example, an arc shape, the flow inside the groove can be smoothly circulated and stabilized. Further, the groove side portion 14a has an inclination so as to expand toward the blade suction surface 13a, thereby effectively guiding the flow into the groove 14 to obtain a drawing effect. Accordingly, it is possible to obtain a cross-flow fan that can be made more efficient with lower noise.

Further, as in the first embodiment, the groove bottom 14b of the groove 14 is formed so as to be closer to the blade negative pressure surface 13a side than the constant thickness line K. With such a configuration, it is possible to obtain the pulling effect by the groove 14, and even if the groove 14 is formed, the thickness of the blade 8c can be secured and the strength can be improved.

Similarly to the first embodiment, the grooves 14 are formed so that the groove depth h <the flat portion length ML is satisfied in all cross sections perpendicular to the rotational axis direction from the blade root portion 8c1 to the blade longitudinal direction tip portion 8c2. Forming. By making the flat portion length ML larger than the groove depth h, the flat portion M can ensure the reattachment after the flow has passed over the groove 14, and the blade suction surface 13a can be obtained by repeating the drawing effect and the reattachment. The flow is always stable without peeling off. For this reason, a cross-flow fan that can achieve low noise and high efficiency can be obtained.

In this way, it is a cross-flow fan that can be released easily and smoothly, reducing noise and increasing efficiency. By installing this cross-flow fan, it is possible to produce a quiet, energy-saving air conditioner. can get.

FIG. 16 is a perspective view showing one blade 8c according to another configuration example of the cross-flow fan according to the present embodiment. In this configuration, the groove width g or the groove depth h of the groove 14 is not the same in the blade longitudinal direction, but is changed at the blade root 8c1 and the blade longitudinal tip 8c2. FIG. 17 shows an enlarged part of a section perpendicular to the rotation axis at the blade longitudinal tip 8c2 of the blade 8c. That is, this is the same as the cross section taken along the line AA of FIG. Here, g1 <g2 and h1 <h2 with respect to the groove width g1 and groove depth h1 of the groove 14 of the blade root portion 8c1 and the groove width g2 and groove depth h2 of the groove 14 of the blade longitudinal direction tip portion 8c2. . The shape of the blade 8c is a tapered shape in which the blade thickness and the chord line length L1 gradually decrease from the blade root 8c1 on the ring 8b side toward the blade longitudinal tip 8c2 which is a free end before fixing. . Further, the concave groove 14 provided on the blade suction surface 13a is formed such that the groove width g and the groove depth h gradually increase from the blade root 8c1 toward the blade longitudinal tip 8c2.

For this reason, in addition to being able to suppress separation due to the pulling effect by the groove 14, when the flow gets over the groove 14, the pulling effect changes gently in the blade longitudinal direction (rotational axis direction). When the flow is discharged from the blade 8c, the flow velocity and the direction of the air gently change in the blade longitudinal direction, so that the flow velocity and the angle in contact with the guide wall 10 change particularly in the blowing region E2. As described above, since the blowing flow does not reach the guide wall 10 at the same time, the pressure fluctuation is attenuated, and noise can be further reduced.

Further, as shown in FIG. 13, when manufacturing by the molding method in which the dies 17 and 18 are released in the blade rotation axis direction AX, the blade outer peripheral side end portion 15a and the blade inner peripheral end portion 15b are slightly in the mold release direction. While having an inclination, the whole recessed part which comprises the groove | channel 14 has some inclination in a mold release direction. For this reason, when resin molding is performed, it is easy to release the entire blade 8 c including the groove 14.

As a result, the once-through fan can further reduce noise and increase efficiency while maintaining productivity. Further, separation can be suppressed against changes in ventilation resistance, a stable blowout flow can be realized, and noise reduction and high efficiency of the cross-flow fan can be achieved.

In the longitudinal direction of the single impeller 8d, the blade 8c has a blade thickness and chord line length L1 from the root 8c1 on the ring 8b side toward the other blade longitudinal tip 8c2 which is the free end before fixing. However, the present invention is not limited to this, but the taper shape gradually decreases and the cross-sectional shape perpendicular to the rotation axis direction gradually decreases. For example, instead of gradually changing the cross-sectional shape of the blade 8c with an inclination, it may be changed stepwise. Even in the configuration that changes stepwise, like the smoothly changed shape, when the mold 18 is slightly moved at the time of mold release, the entire surface of the impeller 8d is placed between the mold 18 and the molded impeller 8d. Since a space is created and separated, mold release is easily and smoothly performed.

Further, the groove width g and the groove depth h of the groove 14 formed on the blade suction surface 13a may not be formed so as to gradually increase from the blade root 8c1 side toward the blade longitudinal tip 8c2. That is, at least one of the groove width g and the groove depth h of the groove 14 may be formed so as to increase gradually or stepwise. It is only necessary that at least one of the groove width g and the groove depth h is gradually or stepwise increased in the blade longitudinal direction. Even if the groove 14 has a concave shape that changes stepwise, when the flow passes over the groove 14, the pulling effect changes in the blade longitudinal direction, and when the flow is discharged from the blade 8c, the flow velocity and wind direction in the blade longitudinal direction. Changes. From this, especially when the blown flow contacts the guide wall 10 in the impeller blowout region E2, the pressure fluctuation is attenuated without reaching at the same time by changing the flow velocity or angle of the blown flow, and the effect of lowering the noise is achieved. Play.

Further, in the direction of the chord line L in FIG. 17, the blade outer peripheral end portion 15a with respect to the groove depth hc near the chord central portion 15c between the blade outer peripheral end portion 15a and the blade inner peripheral end portion 15b of the blade 8c. Alternatively, the groove depth ht on the blade inner peripheral end 15b side may be shallower. In this case, even if the groove 14 is formed on the blade suction surface 13a, the thickness of the blade 8c does not become extremely thin, the hot water circumference at the time of molding does not deteriorate, and the strength at the time of assembly does not occur. Can be improved.

Further, as shown in FIG. 16, even when the groove width g and the groove depth h of the groove 14 are changed between the blade root 8c1 and the blade longitudinal tip 8c2, the groove 14 in the cross section perpendicular to the rotation axis The shape is the same as in the first embodiment. That is, the noise is further reduced by devising the flat part M, the shape of the groove side part 14a, the corners of the groove side part 14a and the blade suction surface 13a, the shape of the groove bottom part 14b, and the like as in the first embodiment. And an efficient once-through fan can be obtained.

FIG. 18 shows another configuration example of the cross-flow fan according to the present embodiment, and is a front view showing one blade 8c. In this configuration, for example, three grooves 14 are provided only on the blade outer peripheral side where the blade outer peripheral side end portion 15a of the blade suction surface 13a exists. The shape of one groove 14 is the same as in FIG.
Thus, in the structure provided only on the blade outer peripheral side, the pulling effect of the groove 14 is obtained at the blade outer peripheral side end portion 15a which is the first separation in the suction region E1, so that the separation can be suppressed and stabilized in the suction region E1. By making it flow, separation in the blowing region E2 can be prevented, and a once-through fan that can be quiet and save energy can be obtained.
Further, a plurality of grooves 14 may be provided on the blade outer peripheral side end portion 15b side and at the blade inner peripheral side end portion 15b side. That is, a plurality of grooves 14 may be provided on the blade outer peripheral side and the blade inner peripheral side, respectively, without being provided in the central portion of the blade 8c. With the configuration in which the groove 14 is provided on the blade inner peripheral side end portion 15b side, an effect of suppressing the separation particularly in the blowing region E2 is obtained. By providing a plurality of grooves 14 extending in the rotational axis direction AX on at least one of the blade outer peripheral end portion 15a side and the blade inner peripheral end portion 15b side, a certain pulling effect can be obtained.

As described in the first embodiment, when the flow is easily separated in the suction region E1 due to the configuration of the device in which the cross-flow fan 8 is mounted, the blade outer peripheral end 15a that is the upstream side of the flow in the suction region E1. It is effective to provide the groove 14 in the vicinity. Further, in the case where the flow is easily separated in the blowing region E2, it is effective to provide the groove 14 in the vicinity of the blade inner peripheral end portion 15b which is the upstream side of the flow in the blowing region E2.
However, as shown in FIG. 8 and FIG. 9, if the groove 14 is provided on the entire surface from the blade outer peripheral end 15 a to the blade inner peripheral end 15 b of the blade negative pressure surface 13 a in a cross section perpendicular to the rotation axis, the blade This is more effective because it can be prevented where peeling occurs on the negative pressure surface 13a.

The groove 14 provided on the blade suction surface 13a described above was provided from the blade root 8c1 to the blade longitudinal tip 8c2, and the length of the groove 14 was all the same. Here, a configuration example in which the length of the groove 14 is variable will be described. FIG. 19 shows another configuration example of the cross-flow fan according to the present embodiment, and is a front view showing one blade 8c. In this configuration, a plurality of grooves 14 are provided on the blade longitudinal tip 8c2 side without being provided on the blade root 8c1 of the blade suction surface 13a. The shape of one groove 14 is the same as that in FIG. 15, and at least one of the groove depth h and the groove width g of the groove 14 increases from the blade root 8c1 toward the blade longitudinal tip 8c2. To form.

When the blade 8c has a tapered shape, the blade longitudinal direction tip 8c2 side has a thin blade thickness and a short chord length L1. For this reason, compared with the blade root 8c1 side, the space between the blade suction surface 13a and the blade pressure surface 13b of the adjacent blade is wide and easily peeled off. Therefore, by forming the groove 14 at least on the blade longitudinal tip 8c2 side, peeling can be suppressed by the pulling effect due to the negative pressure in the groove 14, and noise can be reduced.

Furthermore, the plurality of grooves 14 formed on the blade suction surface 13a are formed so that the length J gradually changes in the blade longitudinal direction of the blade 8c. The end of the plurality of grooves 14 on the blade root 8c1 side is defined as a groove side end 14c, and the grooves 14 are formed so that the groove side ends 14c of the plurality of grooves 14 are inclined with respect to the impeller rotating shaft. Therefore, the length J of the groove 14 in the blade longitudinal direction of the groove 14 changes so as to gradually increase along the outer peripheral direction of the ring 8b. In the configuration shown in FIG. 19, the groove 14 is formed obliquely so that the length J of the groove 14 gradually increases from the blade outer peripheral end 15 a toward the blade inner peripheral end 15 b.

Since the number of grooves 14 in the chord line direction differs depending on the position in the blade longitudinal direction, in the suction region E1, the air flow shown in FIG. 7 varies depending on the position in the blade longitudinal direction. When the cross-flow fan is mounted on, for example, an air conditioner, the suction flow may drift in the suction region E1 due to the influence of a resistor or the like in the blade longitudinal direction. Even if the suction flow is uneven, the drawing effect changes more smoothly in the blade longitudinal direction in the configuration shown in FIG. For this reason, the wind speed distribution can be made uniform, the increase in speed locally on the blade surface can be suppressed, the flow can be stabilized, and the noise can be reduced.

FIG. 20 shows another configuration example of the cross-flow fan according to the present embodiment, and is a front view showing one blade 8c. In this configuration example, the length J of the groove 14 is gradually shortened from the blade outer peripheral end 15a toward the blade inner peripheral end 15b. Even in the groove 14 having such a configuration, the drawing effect changes more smoothly in the longitudinal direction of the blade even if the suction flow is deviated in the suction region E1 due to the influence of a resistor or the like in the longitudinal direction of the blade, as in FIG. For this reason, the wind speed distribution can be made uniform, the increase in speed locally on the blade surface can be suppressed, a stable flow can be realized, and the noise can be reduced.

Further, in the configuration as shown in FIGS. 19 and 20, the change in flow velocity and angle when contacting the guide wall 10 changes smoothly in the longitudinal direction of the blade, the pressure fluctuation is attenuated, and further noise reduction can be achieved.

FIG. 21 shows still another configuration example. The length J of the groove 14 gradually extends from the blade outer peripheral end 15a toward the blade inner peripheral end 15b to the vicinity of the central portion, and gradually decreases from near the central portion toward the blade inner peripheral end 15b. It is comprised as follows. In such a configuration, even if the suction flow is drifted in the suction region E1 due to the influence of a resistor or the like in the blade longitudinal direction, the drawing effect changes more smoothly in the blade longitudinal direction. For this reason, the wind speed distribution can be made uniform, the increase in the flow velocity locally on the blade surface can be suppressed, and the noise can be reduced. Further, in the blowing side region E2, the blowing flow changes smoothly in the blade longitudinal direction, and the flow velocity and angle when contacting the guide wall 10 change smoothly. For this reason, pressure fluctuations are attenuated, and noise can be further reduced.

Further, in the configuration shown in FIG. 21, the blade outer peripheral end 15a and the blade inner peripheral end 15b are thin in the portion where the thickness of the groove 14 is shortened, and the blade thickness near the center in the chord line L direction. The thick part has the length of the groove 14 increased. For this reason, the intensity | strength of the whole wing | blade 8c can be ensured and the buckling at the time of adhering the impeller single-piece | unit 8d by ultrasonic welding etc. can be prevented.
As a result, the cross-flow fan can further reduce noise and secure the strength when assembling the impeller, so there is no assembly loss. By installing this cross-flow fan, a quiet and productive air conditioner can be obtained. .

FIG. 22 shows still another configuration example. In this configuration, the blade length direction J of the plurality of grooves 14 formed on the blade suction surface 13a is irregularly changed. In this case, the number of grooves 14 varies in the chord line L direction depending on the position in the blade longitudinal direction. For this reason, even if drift occurs in the suction region E1 and minute separation occurs in the longitudinal direction of the blade, it is diffused by the flow in the vicinity. In addition, the wind speed distribution can be made uniform and the noise can be reduced.
Further, even if a drift occurs due to dust accumulated on the filter 5 on the upstream side of the cross-flow fan, it is possible to prevent separation and to stabilize the suction flow. Further, the same applies to the blowing region E2, and the blowing flow changes irregularly in the blade longitudinal direction, and the flow velocity and angle when contacting the guide wall 10 change irregularly. For this reason, pressure fluctuations are irregularly attenuated, and noise can be reduced.
It is effective to provide the concave groove 14 provided on the blade negative pressure surface 13a at a location where peeling is considered to occur depending on the situation where the cross-flow fan is operated.

As described above, the disk-shaped support plate 8b whose center of rotation is located at the center, and the plurality of support plates 8b that are arranged along the outer periphery of the support plate 8b and extend in the direction of the rotation axis and are supported by the support plate 8b at both ends. An impeller 8d having a plurality of blades 8c and an impeller 8a formed by fixing a plurality of the impellers 8d in the direction of the rotation axis, and connected to the support plate 8b at one end of the blade 8c. The cross-sectional shape perpendicular to the rotational axis in the connection portion 8c1 is made larger than the cross-sectional shape perpendicular to the rotational axis in the connection portion 8c2 connected to the support plate 8b at the other end of the blade 8c, and the blade 8c. By providing a plurality of concave grooves 14 extending in the direction of the rotation axis on the blade negative pressure surface 13a, which is the rear surface with respect to the rotation direction, it is possible to obtain a cross-flow fan capable of maintaining productivity and reducing noise. Further, it is possible to prevent the backflow to the once-through fan caused by the unstable blowout flow. Furthermore, even if the ventilation resistance increases, the flow is hardly separated at the blade negative pressure surface 13a, and the blowing flow is also stabilized.

In each of FIGS. 18 to 22, a configuration in which at least one of the groove width g and groove depth h of the groove 14 is larger at the blade longitudinal tip 8c2 than at the blade root 8c1 is described. However, it is not limited to this. If the mold release direction is not the impeller rotation direction but a different direction by resin molding, the groove 14 may have the same groove width g and groove depth h. Furthermore, the groove length was changed with the blade longitudinal direction tip 8c2 as a reference in consideration of setting the mold release direction as the impeller rotation direction in resin molding, but if the mold release direction is changed to another direction, the blade A groove with a more irregular position and length may be provided with the base portion 8c1 as a reference, or between the blade longitudinal direction tip portion 8c2 and the blade root portion 8c1 as a reference. If the blade suction surface 13a is configured to extend at least in the rotation axis direction AX and is provided with a flat portion M between the adjacent grooves 14, the flow is to be separated. 14, the air can be drawn toward the blade suction surface 13a to obtain a stable flow.

Further, as shown in FIGS. 16 to 22, the configuration of the groove 14 that changes the groove width G, changes the groove depth h, or changes the groove length J is the same as that of the first embodiment. The blade 8c may be applied to a shape that is not tapered, and the same effect is obtained. Similarly, the same effects can be obtained when applied to the second embodiment.

Particularly, in the air conditioner, as shown in FIG. 2, when the blade 8c passes through the impeller suction region E1 on the heat exchanger 7 side, the suction port 2, the electrostatic precipitator 6, and the filter only above the air conditioner main body. Since a plurality of resistors having different sizes and ventilation resistances such as 5 are arranged unevenly, the suction air speed varies. In addition, when the airflow resistance increases due to dust adhering to the filter arranged on the impeller suction side, it is easy to peel off against the change in the angle of attack of the flow with respect to the blade, and the blowout flow becomes unstable and backflows to the fan. There is a possibility that the floor gets wet when the impeller condenses during operation and releases condensed water to the outside. Therefore, by installing the cross-flow fan according to any of the first to third embodiments, a stable flow can be obtained, noise reduction and high efficiency can be achieved, and a change in ventilation resistance can be prevented. Preventing separation and preventing backflow to the fan due to instability of the blowout flow, resulting in a quiet and high quality air conditioner.

As described above, according to the first to third embodiments, since the plurality of grooves extending in the rotation axis direction AX are formed on the blade negative pressure surface 13a of the impeller of the once-through fan, a stable air flow can be realized. Therefore, it is possible to obtain a cross-flow fan that is audible, quiet, quiet, highly efficient and energy-saving. In addition, by installing this cross-flow fan, a stable air flow can be realized, and during cooling operation, the impeller can be prevented from dewing and releasing condensed water to the outside, and a high-quality air conditioner can be obtained. Can do.

In the first to third embodiments, the configuration example in which the cross-flow fan is mounted on, for example, an air conditioner has been described. However, the present invention is not limited to this. For example, the present invention can be applied to a cross-flow fan mounted on another device such as an air curtain. By using a cross-flow fan that can reduce noise, there is an effect that the noise of a device equipped with the fan can be reduced.

DESCRIPTION OF SYMBOLS 1 Air conditioner main body 2 Suction port 3 Outlet 7 Heat exchanger 8 Cross-flow fan 8a Impeller 8b Support plate 8c Wing 8c1 Wing root part 8c2 Wing longitudinal direction tip 8d Impeller simple substance 9 Stabilizer 10 Guide wall 12 Motor 12a Motor shaft 13a Blade negative pressure surface 13b Blade pressure surface 14 Groove 14a Groove side portion 14b Groove bottom portion 14P Virtual intersection 15a Blade outer peripheral end portion 15b Blade inner peripheral end portion 16 Fixed portion C Opening portion E1 Suction region E2 Outlet region L Blade chord L1 Length of chord line L11 Length of chord line of blade root portion 8c1 L12 Length of chord line of tip portion 8c2 in blade longitudinal direction M Flat portion ML Flat portion length O Center of rotation RO Rotation direction g Groove width g1 Blade root Groove width of portion 8c1 g2 Groove width of blade longitudinal tip 8c2 h Groove depth h1 Groove depth of blade root 8c1 h2 Blade longitudinal tip 8 No. 2 groove depth ht Groove depth in the vicinity of the blade outer peripheral end 15a and blade inner peripheral end 15b hc Groove depth in the vicinity of the central portion in the chord line direction of the blade K Blade outer peripheral side with reference to the blade pressure surface Contour line of thickness of end or blade inner circumferential side end tmax Maximum thickness of blade tmax1 Maximum thickness of blade root 8c1 tmax2 Maximum thickness of blade longitudinal tip 8c2

Claims

A disc-shaped support plate having a center of rotation located at the center, and an impeller having a plurality of blades disposed along the outer periphery of the support plate and extending in the rotation axis direction and supported at both ends by the support plate; ,
An impeller formed by fixing a plurality of impellers alone in the direction of the rotation axis, and a plurality of concave grooves provided on a blade suction surface that is a rear surface with respect to the rotation direction of the blades and extending in the direction of the rotation axis. Prepared,
A once-through fan, wherein the groove is provided with a predetermined interval so as to have a flat portion between adjacent grooves.
A disc-shaped support plate having a center of rotation located at the center, and an impeller having a plurality of blades disposed along the outer periphery of the support plate and extending in the rotation axis direction and supported at both ends by the support plate; ,
An impeller formed by fixing a plurality of impellers alone in the direction of the rotation axis, a motor that rotates the impeller by fixing a motor shaft to the support plate located at an end of the impeller, and
A fixed portion with the motor shaft located inside the impeller alone, and an opening that partially widens the blades of the impeller so that a fixture can be inserted into the fixed portion. And a plurality of concave grooves extending in the rotational axis direction are provided on the blade suction surface, which is the rear surface of the blade adjacent to the opening on the rotational direction side of the impeller. Cross-flow fan characterized by
A disc-shaped support plate having a center of rotation located at the center, and an impeller having a plurality of blades disposed along the outer periphery of the support plate and extending in the rotation axis direction and supported at both ends by the support plate; ,
An impeller formed by fixing a plurality of impellers alone in the direction of the rotation axis,
From the cross-sectional shape perpendicular to the rotation axis at the connection portion connected to the support plate at the other end of the blade, the cross-sectional shape perpendicular to the rotation axis at the connection portion connected to the support plate at one end of the blade. And a plurality of concave grooves extending in the direction of the rotation axis are provided on the blade suction surface which is the rear surface of the blade in the rotation direction.
The cross-flow fan according to claim 3, wherein the groove extending in the rotation axis direction is provided on at least the other end portion of the blade suction surface on the connection portion side.
5. The groove according to claim 2, wherein the groove is provided at a predetermined interval so as to have a flat portion between adjacent grooves in a cross section perpendicular to the rotation axis. Cross-flow fan.
The cross-flow fan according to claim 1 or 5, wherein, in a cross section perpendicular to the rotation axis, an interval between the adjacent grooves is larger than a groove depth of the concave groove.
In the cross section perpendicular to the rotation axis, the groove side portion and the groove bottom portion facing each other constitute the concave groove, and the connection portion between the groove side portion and the blade suction surface is rounded. The once-through fan according to any one of claims 1 to 6.
In the cross section perpendicular to the rotation axis, the groove side portion and the groove bottom portion facing each other constitute the concave groove, the groove bottom portion is rounded, and the groove side portion continuous to the groove bottom portion is the wing. The cross-flow fan according to any one of claims 1 to 7, wherein the cross-flow fan has a shape that expands toward the suction surface.
In the cross section perpendicular to the rotation axis, the plurality of blades are between a blade outer peripheral side end located on the outer peripheral side of the support plate and a blade inner peripheral end located on the inner peripheral side of the support plate. The blade is substantially arc-shaped and has a blade at a central portion between the blade outer peripheral end and the blade inner peripheral end rather than the blade thickness at the blade outer peripheral end and the blade inner peripheral end. The blade suction surface is increased in thickness by being separated by at least the blade thickness at the blade outer peripheral end or the blade inner peripheral end from the blade pressure surface that is the front surface in the rotational direction of the blade. The cross-flow fan according to any one of claims 1 to 8, wherein the concave groove is provided.
In the cross section perpendicular to the rotation axis, the plurality of blades are between a blade outer peripheral side end located on the outer peripheral side of the support plate and a blade inner peripheral end located on the inner peripheral side of the support plate. 10. The structure according to claim 1, wherein the plurality of grooves are provided in the vicinity of at least one end of the blade outer peripheral side end and the blade inner peripheral side end. The once-through fan according to item.
The cross-section perpendicular to the rotation axis, at least one of the groove width and the groove depth of the concave groove is increased or decreased in the rotation axis direction. The once-through fan according to item 1.
12. The length of the rotation axis direction of at least a part of the plurality of grooves formed on the blade suction surface is irregularly changed. The once-through fan according to item 1.
Of the plurality of grooves formed on the blade suction surface, the length in the rotation axis direction of at least some of the grooves is changed so as to gradually increase or decrease along the outer circumferential direction of the support plate. The cross-flow fan according to any one of claims 1 to 11, wherein the cross-flow fan is provided.
In the cross section perpendicular to the rotation axis, the plurality of blades are between a blade outer peripheral side end located on the outer peripheral side of the support plate and a blade inner peripheral end located on the inner peripheral side of the support plate. The groove depth in the central portion between the blade outer peripheral side end and the blade inner peripheral end of the plurality of concave grooves formed on the blade suction surface is a substantially arc shape, The cross-flow fan according to any one of claims 1 to 13, wherein the cross-sectional fan is larger than a groove depth in the vicinity of the end portion and the end portion on the blade inner peripheral side.
A cross-flow fan according to claim 1, and a heat exchanger disposed in a suction-side flow path formed by the cross-flow fan and exchanging heat with the sucked air. An air conditioner characterized by that.