JP5211813B2 - Ceiling fan - Google Patents

Description

  The present invention relates to a ceiling fan that is installed on a ceiling and is used for adjusting the temperature of a sensible temperature by direct wind or circulating indoor air.

  Conventionally, this type of ceiling fan is known to be fixed to a rotating body that is rotated by an electric motor via a connecting member that supports one end of a long other blade (see, for example, Patent Document 1).

  Hereinafter, the ceiling fan will be described with reference to FIG.

  As shown in the figure, the overall structure of the ceiling fan 101 is composed of a canopy (upper cover) 102, an outer rotating body 103 and a lower cover 104 of an electric motor, and a blade 106 attached to a holder 105 of the outer rotating body 103. The simple mounting bracket 107 inside the canopy 102 is screwed to the ceiling 108 and the ceiling fan 101 is suspended.

  In the above configuration, the blades 106 are attached at a predetermined angle in the rotation direction around the rotation axis. When the blades 106 are rotated by the electric motor, the blades 106 are boosted by the pressure increase action of the blades 106 to rotate in the forward direction. Air that has passed between the ceiling 108 and the blades 106 from the outside is blown downward, and in reverse rotation, air is blown to the outer periphery of the blades 106 from below the blades 106 through the space between the ceiling 108 and the blades 106. Therefore, it is used in the forward rotation direction to improve comfort by receiving the airflow directly in the summer, and promotes the circulation of air throughout the room so that it does not feel the cold wind due to the direct wind mainly in the winter. When it is removed, it is used in reverse rotation.

  Moreover, what changes a wind direction by providing several wind direction blade | wing in parallel under the blade | wing is known (for example, refer patent document 2).

  Hereinafter, the ceiling fan will be described with reference to FIG.

  As shown in the figure, a wind direction blade 109 is provided below the ceiling fan 1, and the wind direction blade 109 can change the inclination in the center direction or the outer peripheral direction.

In the above configuration, as the blades 106 rotate, the air is blown from the air outlet 110, and the wind direction range is expanded by the inclination of the wind direction blade 109, so that the airflow can be concentrated and expanded.
Japanese Patent Laid-Open No. 11-210678 JP 59-265762 A

  In such a conventional ceiling fan, the air flow at the time of forward rotation that requires improvement in wind reception feeling is caused by the large suction flow of the inner component passing through the vicinity of the ceiling toward the ceiling fan. The inner flow is toward the central axis. Therefore, the ventilation range of the ceiling fan for improving wind feeling is narrowed, and there is a problem that a comfortable area for the wind receiver is limited.

  Moreover, in the wind direction blade | wing provided in parallel, there existed a subject that there was directivity in concentration and expansion | swelling of an air current, and the nonuniformity of an air flow range could be performed in the circumferential direction.

  The present invention solves such conventional problems, and expands the comfortable area of the wind receiver, and realizes air blowing that reduces the unevenness of the air flow range by changing the air flow direction in the entire circumferential direction. The purpose is to do.

  In order to achieve the above object, the ceiling fan of the present invention has a motor suspended from the ceiling, a first impeller composed of a plurality of blades rotated by the motor, and rotation of the first impeller. A second impeller comprising a plurality of blades arranged substantially parallel to the axial direction is provided, and the mounting angle in the circumferential direction with respect to the horizontal plane of a part or all of the second impeller can be changed. It is characterized by that.

  Another means is characterized in that the rotational speed of the first impeller is changed simultaneously with the operation in the airflow diffusion mode and the mode change in the airflow concentration mode.

  Another means is characterized in that the number of rotations of the first impeller is automatically changed over time during operation in the airflow diffusion mode.

  The other means is characterized in that the rotational speed of the first impeller is changed over time with a 1 / f fluctuation characteristic during operation in the airflow diffusion mode.

  Another means is characterized in that the operation in the airflow diffusion mode and the operation in the airflow concentration mode are automatically switched.

  The other means is characterized in that the operation in the airflow diffusion mode and the operation in the airflow concentration mode are switched based on the time setting.

  ADVANTAGE OF THE INVENTION According to this invention, the ceiling fan which can expand the comfortable area | region of a wind receiver and can implement | achieve the ventilation which changed the airflow direction of the perimeter direction and reduced the nonuniformity of the airflow range can be provided.

The electric fan according to claim 1 of the present invention includes an electric motor suspended from a ceiling, a first impeller composed of a plurality of blades rotated by the electric motor, and a rotation axis direction of the first impeller. A second impeller composed of a plurality of blades arranged substantially parallel to each other, and changes a circumferential mounting angle of a part or all of the second impeller with respect to a horizontal plane; Since the blades of the second impeller that changes the width are arranged in the circumferential direction, the airflow direction can be changed in the entire circumferential direction, and the comfortable area of the wind receiver can be expanded without unevenness. Also, the mounting angle of the blades of the second impeller is changed from 30 ° to 80 °, avoiding the range of the mounting angle where the loss of the blowing effect due to the collision is increased, and the air flow direction in an efficient state Can change. Also, the range of the airflow diffusion mode in which the attachment angle of the blades of the second impeller is 30 ° to 45 °, and the range of the airflow concentration mode in which the attachment angle of the blades of the second impeller is 65 ° to 80 °. The mode can be switched at the same time so that the wind speed can be kept constant in any mode by changing the rotation speed against the mode change in which the wind speed changes when the work of the ceiling fan is equal. The change of this can be made larger and the comfort can be improved.

The invention according to claim 2 is such that the rotational speed of the first impeller is changed simultaneously with the operation in the airflow diffusion mode and the mode change in the airflow concentration mode, and the work of the ceiling fan is equal. With respect to the mode change in which the wind speed changes, the wind speed can be made constant in any mode by changing the rotation speed, and the change at the time of mode switching can be made larger, so that the comfort can be improved.

The invention of claim 3 Symbol placement is for changing over time and automatically the rotational speed of the first impeller during operation of a stream spreading mode, expanding the blowing range occurs stirring airflow speed change it can.

The invention according to claim 4 changes the rotational speed of the first impeller over time with a 1 / f fluctuation characteristic during operation in the airflow diffusion mode, and makes the change in the airflow closer to natural wind. By setting it as a change, the air blowing range can be expanded while improving comfort.

The invention according to claim 5 automatically switches between the operation in the airflow diffusion mode and the operation in the airflow concentration mode, and all of the plurality of wind receivers at different positions can receive the airflow.

The invention according to claim 6 switches between the operation in the airflow diffusion mode and the operation in the airflow concentration mode based on the time setting, and all of the plurality of wind receivers at different positions receive the airflow uniformly. be able to.

  The invention according to claim 34 is such that switching of the mounting angle of the blades of the second impeller or switching between the operation method mode and the airflow mode can be selected by a remote controller, and from a wind receiver at an arbitrary location. Operation becomes possible and operability can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a side view of a ceiling fan according to the first embodiment, FIG. 2 is a bottom view, and FIGS. 3 and 4 are sectional views of constant radius of blades of a first impeller and a second impeller. It is.

  As shown in these drawings, the ceiling fan 1 includes a motor (not shown) that is suspended from the ceiling 2 and provided inside the case 3, and a plurality of blades 4 that are rotated by the motor. A first impeller 5 and a second impeller 7 composed of a plurality of blades 6 arranged in parallel to the lower direction of the rotation axis of the first impeller 5, A configuration in which a circumferential mounting angle 9 with respect to a horizontal plane 8 respectively defined by all constant radius sections of the blade 6 is changed by a second electric motor and a gear (not shown) inside the case 3 provided inside. This can be remotely controlled by a wireless remote controller (not shown).

  As shown in FIGS. 1 and 2, in the second impeller 7, all the blades 6 are changed at the same mounting angle, and in the same circumferential direction as the direction in which the first impeller 5 rotates. It is constrained not to rotate.

  Further, the outer diameter of the second impeller 7 is smaller than that of the first impeller 5 so as to avoid the turbulence 19 of the air flow generated at the outer periphery of the first impeller 5, for example, the first impeller 5 The outer diameter of the second impeller 7 is 1100 mm with respect to the outer diameter of the car 5 of 1500 mm.

  As shown in FIGS. 3 and 4, the attachment angle 9 of the blade 6 of the second impeller 7 and the attachment angle 10 of the blade 4 of the first impeller 5 are set so that the inclinations are reversed, The radial constant cross-sectional shape 11 of the blade 6 of the second impeller 7 is convex downward, for example, a cross-sectional shape on an arc.

  Further, the blade 6 of the second impeller 7 is inclined so that the distance 12 to the radial direction becomes larger in the rotation reverse direction toward the outer periphery, and this inclination is set as a deviation angle 22, for example, the deviation angle 22 is 15 °. It is about.

  Further, the number of blades 4 of the first impeller 5 is five, the number of blades 6 of the second impeller 7 is six, and the number of blades 6 of the second impeller 7 is increased. ing.

  In addition, in the air flow diffusion mode in which the attachment angle 9 of the blades 6 of the second impeller 7 is the smallest 30 degrees in the air flow diffusion mode and in the air flow concentration mode in which the attachment angle 9 is the largest 80 degrees. The mounting angle 9 can be switched for each airflow mode with the constant radius section shape 14.

  In addition, the first impeller 5 can adjust the air volume by switching notches having different rotational speeds, but even in the notches, the rotational speed of the airflow diffusion mode is set to be larger than the airflow concentration mode. Even in the notch, the airflow concentration mode is set to 220 rpm with respect to the airflow concentration mode of 200 rpm.

  In the above configuration, by rotating the electric motor to rotate the first impeller 5, the blades 4 of the first impeller pressurize air on the lower surface to generate a downward airflow 15. Since the second impeller 7 is provided on the downstream side of the airflow, the blades 6 of the second impeller 7 directly receive the airflow from the first impeller 5 and follow the rotation direction on the surface of the blades 6. However, the direction of the airflow can be expanded by changing the direction and becomes a comfortable area for the wind recipient, and the airflow 16 when the mounting angle is small is changed from the downward component to the rotational direction component so that the blowing range is widened. When the mounting angle is large, the air flow 17 is narrowed by the rotation direction component being changed to the downward direction component.

  At this time, since the blades of the second impeller that changes the wind direction are arranged in the circumferential direction, the airflow direction can be changed in the entire circumferential direction, and the comfortable area of the wind receiver can be expanded without unevenness. It is possible to realize a wide range of air blowing that was difficult in the past, and by using the second motor and wireless remote control to change the mounting angle 9, the elevation angle can be changed without directly touching the wing, Remote operation is possible from a wind receiver at an arbitrary location, and operability can be improved.

  In addition, since all the attachment angles 9 of the blades 6 of the second impeller 7 are the same angle, the airflow is changed in the same way by all the blades 6, so that it is possible to change the airflow with less unevenness in the entire circumferential direction. .

  In addition, although the wind direction of the airflow changes greatly due to the reaction force of the second impeller 7, the reduction of the reaction force due to the movement of the second impeller 7 due to the reaction force acting on the airflow is prevented, so the effect of the change in the wind direction is reduced. It can be increased.

  In addition, since the outer diameter of the second impeller 7 is smaller than the outer diameter of the first impeller 5, the second impeller 7 avoids the region of the outer peripheral portion of the first impeller that is likely to cause the turbulence 19. Since the impingement of the impeller 7 and turbulence is prevented, the wind direction can be changed efficiently even if the mounting angle changes.

  Further, since the mounting angle 9 of the second impeller 7 and the mounting angle 10 of the first impeller 5 are reversed, resistance to the flow from the blades 4 of the first impeller 5 is reduced. In this way, the blade 6 of the second impeller 7 is provided, and further, by forming a shape that protrudes downward, it becomes a shape that efficiently converts the downward direction component of the airflow into the rotational direction component, and widens the blowing range Particularly high efficiency.

  Further, FIG. 5 shows the influence of the deviation angle 22 between the center line 20 of the blade of the second impeller 7 and the radial direction 21 on the reach ratio of the reference wind speed based on the actually measured values. By tilting in the reverse direction of rotation as about 15 °, it is configured to receive the radial inner component of the airflow from the first impeller 5 and efficiently convert it into the rotational direction component, and to expand the airflow range Become.

  Further, since the number of blades 6 of the second impeller 7 is larger than that of the blades 4 of the first impeller 5, the blades of the first impeller and the second impeller interfere with each other. Since the number of locations that simultaneously interfere with the wind noise is reduced, noise can be reduced, and the effect of the change in wind direction can be increased by increasing the influence of the blades 6 of the second impeller 7.

  Moreover, FIG. 6 shows the influence of the mounting angle 9 of the blade 6 of the second impeller 7 on the reach ratio of the reference wind speed based on the actual measurement values. The narrow airflow range of 45 ° or less and 65 ° or more. The difference in airflow can be clearly distinguished in the case of a wide airflow range, and when the angle is 30 ° or less and 80 ° or more, the angle at which the loss of the blowing effect due to the collision increases, so the operation mode is switched between 30 ° and 80 °. Thus, the winder can easily perform the operation without struggling with fine adjustments, and the airflow direction can be changed in an efficient state.

  In addition, the change in the number of revolutions at the time of mode switching increases the number of revolutions in the airflow diffusion mode in contrast to the change in the wind speed in the airflow diffusion mode when the number of rotations of the ceiling fan is constant and the work amount is equal. Since the wind speed can be recovered, it is possible to improve the comfort by setting it to be constant in any mode.

  In the first embodiment, the inclination angles 9 of all the blades 6 of the second impeller 7 are changed. However, even if only some of the blades 6 are moved, the airflow range in that direction may be changed. It becomes possible.

  Moreover, although the 2nd impeller 7 is restrained in the circumferential direction, you may enable it to rotate freely, In this case, the drag which changes the wind of the blade | wing 6 of the 2nd impeller 7 becomes small. As a result, the change in the direction of the airflow is reduced, but the change in the airflow can be reduced by rotating to reduce the unevenness in the circumferential direction.

  Further, although the number of blades 4 of the first impeller 5 and the number of blades 6 of the second impeller 7 are different, noise reduction can be achieved by setting one to be not a divisor of the other. The effect is huge.

  In addition, the rotational speed of the first impeller 5 in the airflow diffusion mode is constant at 220 rpm. However, by changing the rotational speed automatically with time by giving a width of about 20 rpm, the airflow can be changed by changing the rotational speed. It becomes possible to further expand the air blowing range.

  In addition, the rotational speed of the first impeller may be changed over time with the 1 / f fluctuation characteristic during operation in the air flow diffusion mode, and the change in the air flow is made to be a change close to natural wind. The air blowing range can be expanded while improving the performance.

  In addition, it is possible to switch between the operation in the airflow diffusion mode and the airflow concentration mode, but it may be switched automatically based on a time setting that switches every 10 seconds, for example, and all of the wind receivers at different positions Can receive airflow.

  The same effect can be obtained not by the second electric motor for moving the blades 6 of the second impeller 7 but by an electric actuator such as a piezo element whose shape changes due to a voltage change.

( Reference form 1 )
Figure 7 is the radius constant cross-sectional view of the blade of the blade and a second impeller of the first impeller of the ceiling fan in the first reference, the detailed description of the embodiment 1 and the same parts of the embodiment will be omitted.

  As shown in the figure, the attachment angle 9 of the blade 6 of the second impeller 7 and the attachment angle 10 of the blade 4 of the first impeller 5 are set so that the inclination is reversed, and the second impeller 7 The constant-radius cross-sectional shape 23 of the blade 6 is convex upward.

  In the above-described configuration, the mounting angle 9 of the second impeller 7 and the mounting angle 10 of the first impeller 5 are opposite to each other, so that resistance to the flow from the blades 4 of the first impeller 5 is achieved. The blades 6 of the second impeller 7 are provided so as to be reduced, and further, by forming a convex shape upward, the rotational direction component of the air flow 24 is efficiently converted into the downward component, and the air blowing range This is particularly efficient when widening the range.

( Reference form 2 )
FIG. 8 is a constant radius sectional view of the blades of the first impeller and the second impeller of the ceiling fan in Reference Embodiment 2 , and detailed description of the same parts as those in Embodiment 1 is omitted.

  As shown in the figure, the attachment angle 9 of the blade 6 of the second impeller 7 and the attachment angle 10 of the blade 4 of the first impeller 5 are set so that the inclination is reversed, and the second impeller 7 The constant-radius cross-sectional shape 25 of the blade 6 is substantially S-shaped.

  In the above-described configuration, the mounting angle 9 of the second impeller 7 and the mounting angle 10 of the first impeller 5 are opposite to each other, so that resistance to the flow from the blades 4 of the first impeller 5 is achieved. Since the blades 6 of the second impeller 7 are provided so as to be reduced, and the shape is substantially S-shaped, a curved surface having a plurality of inflection points 27 is obtained, so that the strength can be improved.

( Reference form 3 )
FIG. 9 is a constant radius sectional view of the inner peripheral end and the outer peripheral end of the first impeller blades and the second impeller blades of the ceiling fan in Reference Embodiment 3 , and is the same as in Embodiment 1 The detailed description of is omitted.

  As shown in the figure, the second impeller 7 has a radial direction so that the mounting angle 31 of the blade section 30 at the outer peripheral end gradually becomes smaller than the mounting angle 29 of the blade section 28 at the inner peripheral end. For example, the slant angle 32 changes by about 10 °.

  In the above configuration, the mounting angle 29 is increased at the inner peripheral end in accordance with the air flow 33 in the inner peripheral portion having a small radius and a small rotational direction component, and the outer periphery in accordance with the air flow 34 in the outer peripheral portion having a large radius and a large rotational direction component. Since the attachment angle 31 is made small at the end, a blade shape is formed in accordance with the airflow from the first impeller 5, and the airflow direction can be changed efficiently. FIG. 10 shows the influence of the fin angle 32 on the reach distance ratio of the reference wind speed from the actually measured value. Compared to the case where there is no fin, the twist angle 32 of 10 ° increases the reach distance and reduces the blowing range. Can be wide.

( Reference form 4 )
Figure 11 is a bottom view of the ceiling fan in Reference Embodiment 4, a detailed description of the embodiment 1 and the same parts of the embodiment will be omitted.

  As shown in the figure, the second impeller 7 has a shape in which, for example, the blade width 35 of the inner peripheral end is changed from 45 mm to 70 mm of the maximum blade width 36 and further tapered toward the outer peripheral end. Changes in the radial direction. The angle 38 with respect to the radial direction of the center line 37 of the blades of the first impeller 5 is different from the angle 40 with respect to the radial direction of the center line 39 of the blades of the second impeller 7.

  In the said structure, in the 2nd impeller 7, the weight reduction of the 2nd impeller 7 is attained by reducing the blade width in the radial inner area | region where a flow velocity is small, or a radial outer area | region where disturbance is large. .

  Further, the timing of interference is shifted by avoiding simultaneous interference in the entire radial direction by shifting the wing centerline 37 of the first impeller 5 and the wing centerline 39 of the second impeller 7. Since the wind noise generated by the interference between the respective blades of the first impeller 5 and the second impeller 7 is reduced, the noise is reduced.

( Reference form 5 )
Figure 12 is a bottom view of the ceiling fan according to the fifth reference, the detailed description of the embodiment 1 and the same parts of the embodiment will be omitted.

  As shown in the figure, the blades 6 of the second impeller 7 are arranged at irregular intervals in the circumferential direction, and the blades 4 of the first impeller 5 are arranged at irregular intervals in the circumferential direction. Here, the unequal interval means that the interval angle of the blades in the circumferential direction is different. For example, the intervals of the second impeller 7 are 72 °, 81 °, 99 °, 108 ° and the first impeller 5. The intervals are 77 °, 86 °, 94 °, and 103 °.

  With the above configuration, the wind noise generated by the interference between the blades of the first impeller 5 and the second impeller 7 is that the plurality of blades interfere simultaneously if the intervals are the same. Since the timing of interference is shifted, noise can be reduced.

( Reference form 6 )
FIG. 13 is a side view of Reference Embodiment 6 , FIG. 14 is a horizontal sectional view, and a detailed description of the same parts as Embodiment 1 is omitted.

  As shown in the figure, rectifying fins 42 are provided only on the lower surface 41 of the blades of the first impeller 5.

  Moreover, the rotation reverse direction side 43 of the rectifying fin 42 has a shape curved outward in the radial direction.

  In the above configuration, the rotational direction component of the air flow 44 in the first impeller 5 is changed to the outside in the radial direction, and the blowing range can be expanded.

  Moreover, since the effect of scraping off the airflow on the lower surface and changing the direction is great, the expansion of the entire size can be suppressed and the blowing range can be expanded by the amount not installed on the upper surface than the installation on the upper surface.

  Further, the rotational direction component is changed to the outside in the radial direction on the downstream side of the air flow 44 of the rectifying fin 42, so that the blowing range can be further expanded.

( Reference form 7 )
15 is a side view of Reference Embodiment 7 , FIG. 16 is a horizontal sectional view, and a detailed description of the same parts as Embodiment 1 is omitted.

  As shown in the figure, the rectifying fins 46 project only from the upper surface 45 of the blades of the second impeller 7.

  Further, the rotation direction side 47 of the rectifying fin 46 has a shape curved outward in the radial direction.

  In the above configuration, the rotational direction component of the air flow 48 in the second impeller 7 is changed to the outside in the radial direction, and the blowing range can be expanded.

  In addition, since the effect of changing the direction by strongly receiving the airflow at the upper surface is great, it is possible to widen the control range of the airflow direction while suppressing the expansion of the overall dimensions as compared with the installation at the lower surface.

  Further, the rotational direction component is changed to the outside in the radial direction on the downstream side of the air flow 48 of the rectifying fins 46, so that the blowing range can be further expanded.

  The ceiling fan according to the present invention has an effect of enlarging a comfortable area of the wind receiver and realizing a wide range of air blowing that has been difficult in the past by changing the air flow direction in the entire circumferential direction. In addition, it is useful as a ceiling fan used to adjust the temperature of sensation by direct wind and to circulate indoor air.

Side view of the ceiling fan according to the first embodiment of the present invention. The bottom view of the ceiling fan of Embodiment 1 of this invention Sectional drawing with constant radius of blades of first impeller and second impeller of Embodiment 1 of the present invention Sectional drawing with constant radius of blades of first impeller and second impeller of Embodiment 1 of the present invention The graph which shows the relationship between the shift | offset | difference angle of Embodiment 1 of this invention, and arrival distance ratio The graph which shows the relationship between the attachment angle of Embodiment 1 of this invention, and reach | attainment distance ratio Sectional drawing with constant radius of blades of first impeller and second impeller of Reference Embodiment 1 of the present invention Sectional drawing with constant radius of blades of first impeller and second impeller of Reference Embodiment 2 of the present invention Radial constant sectional view of inner peripheral end and outer peripheral end of first impeller blade and second impeller blade of Reference Embodiment 3 of the present invention Constant radial sectional view The graph which shows the relationship between the ridge angle and the reach distance ratio of the reference form 3 of the present invention The bottom view of the ceiling fan of the reference form 4 of the present invention The bottom view of the ceiling fan of the reference form 5 of the present invention Side view of Reference Embodiment 6 of the present invention Horizontal sectional view of Reference Embodiment 6 of the present invention Side view of Reference Embodiment 7 of the present invention Horizontal sectional view of Reference Embodiment 7 of the present invention Side view of a conventional ceiling fan Side view of another conventional ceiling fan

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceiling fan 2 Ceiling 3 Case 4 Wings 5 1st impeller 6 Wings 7 2nd impeller 8 Horizontal plane 9 Mounting angle 10 Mounting angle 11 Radius constant cross-sectional shape 12 Distance from radial direction 13 Radius constant cross-sectional shape 14 Radius constant Cross-sectional shape 15 Downward airflow 16 Airflow when mounting angle is small 17 Airflow when mounting angle is large 18 Center portion 19 Airflow turbulence 20 Wing centerline 21 Radial direction 22 Deviation angle 23 Radius constant cross-sectional shape 24 Airflow 25 Radius constant Cross-sectional shape 26 Airflow 27 Inflection point 28 Blade cross section at inner peripheral end 29 Mounting angle 30 Blade cross section at outer peripheral end 31 Mounting angle 32 Hinge angle 33 Air flow at inner peripheral portion 34 Air flow at outer peripheral portion 35 Blade at inner peripheral end portion Width 36 Maximum blade width 37 Blade centerline 38 Angle relative to radial direction 39 Blade centerline 40 Angle relative to radial direction 41 Lower surface of blade 42 Rectifier fin 4 Rotation reverse side 44 airflow 45 wings of the upper surface 46 rectifying fins 47 rotational direction 48 air flow

Claims (6)

An electric motor suspended from the ceiling, a first impeller composed of a plurality of blades rotated by the electric motor, and a plurality of blades arranged substantially parallel to the rotation axis direction of the first impeller A second impeller that can be configured to change a circumferential mounting angle of a part or all of the second impeller with respect to a horizontal plane;
The mounting angle of the blades of the second impeller is 30 ° to 80 °,
The range of the air flow diffusion mode in which the attachment angle of the blades of the second impeller is 30 ° to 45 ° and the range of the air flow concentration mode in which the attachment angle of the blades of the second impeller is 65 ° to 80 °. heaven Iogi characterized in that the switchable configured. Ceiling fan according to claim 1, characterized in that so as to vary the rotational speed at the same time the first impeller and the mode change operation during the air flow concentration mode of a stream spreading mode. The ceiling fan according to claim 1 or 2 , wherein the rotational speed of the first impeller is automatically changed over time during operation in the air flow diffusion mode. The ceiling fan according to claim 1 or 2 , wherein the rotational speed of the first impeller is changed over time with a 1 / f fluctuation characteristic during operation in the air flow diffusion mode. The ceiling fan according to any one of claims 1 to 4 , wherein the operation in the airflow diffusion mode and the operation in the airflow concentration mode are automatically switched. 6. The ceiling fan according to claim 5 , wherein the operation in the airflow diffusion mode and the operation in the airflow concentration mode are switched based on the time setting.

Images