JP2008292137A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner suppressing generation of discrete frequency noise while suppressing increase of broadband noise, and improving power efficiency. <P>SOLUTION: The air conditioner 1A includes a cross flow fan 4 constituting an impeller 5, and a ventilation passage 10, and having a scroll part 7A having a guide wall surface 7a guiding an air flow from the back of the impeller 5 to a blowout port 11. In the guide wall surface 7a of the air conditioner 1A, an end part on a blowout port 11 side is formed to be the same height over a whole range in an axial direction of the impeller 5, and a wall surface shape in a vertical cross-section in the axial direction of the impeller 5 is projected to the outside of the ventilation passage 10, and a wall surface shape in a cross-section orthogonal to an air flow direction in which a projection amount to the outside of the ventilation passage 10 is gradually decreased from a center part in the axial direction of the impeller 5 toward both end parts, is constituted of a curved surface which is continuous from the back of the impeller 5 to the vicinity of the end part on the blowout port 11 side and then is connected to the end part of the blowout port 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an air conditioner equipped with a cross flow fan.

  In a conventional air conditioner, an indoor heat exchanger is arranged in parallel with the cross flow fan upstream of the cross flow fan, and a casing front plate for partitioning the inlet and the outlet is provided at the lower part of the indoor heat exchanger. An air passage is constituted by the casing front plate, the indoor heat exchanger, and the casing rear plate for guiding air to the back of the cross flow fan. And the bottom part of the casing rear plate is formed such that the height in the vicinity of both ends in the crossflow fan axial direction is stepped lower than the height in the vicinity of the center part (see, for example, Patent Document 1). .

  Since the height of both ends of the bottom in the front view of the air outlet is stepped lower from the vicinity of the center, the air volume is originally less than the vicinity of the center and the both ends of the bottom where the static pressure was low The cross-sectional area of the air passage is enlarged and the static pressure is increased. Thereby, the air volume distribution which became non-uniform in the center part and both ends of the blower outlet was equalized, and the ventilation performance was improved.

JP-A-9-229403

  However, in the front view of the air outlet of the conventional air conditioner, the same height as the height of the central portion from the end on the air outlet side of the bottom of the casing rear plate formed so as to be lower than the central portion. The wall surface protruding in the direction is provided substantially perpendicular to the airflow direction. In addition, the wall surface protruding from the bottom portion is arranged in a step shape so as to block the air flow, and the turbulent airflow is generated when the air flow reaching the outlet through both ends of the bottom portion collides with the wall surface protruding from the bottom portion, Broadband noise was increasing. In addition, since the area of the air outlet is changed in a step shape with respect to the cross-sectional shape of the air passage on the cross flow fan side of the air outlet, the airflow blown out from the air outlet is the cross flow of the air outlet. As compared with the air passage on the fan side, the dynamic pressure is rapidly increased and the speed is increased. Since the static pressure is reconverted so as to increase the dynamic pressure rapidly, energy loss is increased, and the power efficiency of the conventional air conditioner itself is reduced.

In an air conditioner equipped with this type of crossflow fan, a fundamental frequency corresponding to the product NZ of the rotational speed N of the crossflow fan and the number of blades Z disposed on the outer periphery of the crossflow fan is set. Discrete frequency noise is often generated and is a problem.
The discrete frequency noise increases as the air volume fluctuations and pressure fluctuations in the cross section perpendicular to the axial direction of the crossflow fan become uniform in the axial direction of the crossflow fan. In other words, discrete frequency noise is caused by the position and timing (simultaneity) of the airflow fluctuation and pressure fluctuation in the cross section perpendicular to the axial direction of the crossflow fan in the airflow flowing through the crossflow fan. It becomes larger as it is uniform (stronger).

  As described above, in the conventional air conditioner, the bottom portion of the casing rear plate is formed such that the height in the vicinity of both ends is lowered stepwise from the height in the vicinity of the central portion in the front view of the outlet. . In such a case, the simultaneity of the occurrence of air volume fluctuations and pressure fluctuations is perpendicular to the axial direction of the crossflow fan including the boundary between the center part of the bottom part of the casing rear plate whose height has been displaced stepwise and both side parts. Discrete frequency noise is reduced because it is not uniform on both sides in the axial direction of a cross-flow fan with a simple cross section. However, the simultaneity of the flow rate fluctuation and pressure fluctuation of the airflow flowing through the crossflow fan changes only in the cross section perpendicular to the axial direction of the crossflow fan including the above-mentioned boundary, and the airflow flowing through the other air passages Since the simultaneity of the air volume fluctuation and the pressure fluctuation is kept uniform in the axial direction of the cross flow fan, the amount of reduction of the discrete frequency noise is small.

  The present invention has been made to solve the above-described problem, and is an air conditioner capable of suppressing the increase of wideband noise, greatly suppressing the generation of discrete frequency noise, and further improving the power efficiency. The purpose is to obtain.

  An air conditioner according to the present invention includes an impeller and a cross flow fan having a scroll portion having a guide wall surface that guides an air flow from the back of the impeller to a blowout port. The end on the outlet side is formed at the same height over the entire area in the axial direction of the impeller, has a wall surface shape in a cross section perpendicular to the axial direction of the impeller, and protrudes outside the ventilation path. The wall shape in the cross section perpendicular to the airflow direction in which the amount of outward protrusion gradually decreases from the central part in the axial direction of the impeller toward both ends, continues from the rear of the impeller to the vicinity of the end on the outlet side, Thereafter, the difference in the amount of protrusion to the outside of the ventilation path in the axial direction of the impeller is gradually reduced toward the outlet in the airflow direction, and the outlet formed at the same height over the entire area in the axial direction of the impeller It is comprised by the curved surface connected to the edge part of the side.

  According to the present invention, since the static pressure and the dynamic pressure continuously change in the axial direction in the airflow flowing through the impeller, the effect of suppressing the generation of discrete frequency noise is maximized. In addition, since the airflow flowing through the impeller flows smoothly through the ventilation path and reaches the outlet, turbulence is not generated, and an increase in broadband noise can be suppressed and power efficiency is improved. be able to.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a side sectional view of an indoor unit of an air conditioner according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of a scroll portion of the air conditioner according to Embodiment 1 of the present invention. FIG. 3 is a diagram showing the air volume and direction of the airflow at the air outlet of the air conditioner according to Embodiment 1 of the present invention, and FIG. 4 shows the air volume and direction of the air stream at the air outlet of the comparative example. 5 and 5 are diagrams showing the relationship between the maximum wall surface distance δ / scroll portion length L and power consumption in the air conditioner according to Embodiment 1 of the present invention.

  In FIG. 1, an air conditioner 1 </ b> A includes a design panel 2 having an inlet 2 a that takes in indoor air, an impeller 5, and a diffuser 6, and a ventilation path formed between the inlet 2 a and the outlet 11. 10 includes a cross flow fan 4 that guides air taken from the suction port 2 a to the blower outlet 11, a heat exchanger 3 disposed on the upstream side of the impeller 5, and a side wall plate 9.

Next, the air conditioner 1A will be described in detail.
The diffuser 6 includes a scroll portion 7A and a stabilizer 8. The scroll portion 7A is provided on the back side of the cylindrical impeller 5 arranged with the axial direction horizontal, and the design panel 2 covers the upper portion of the impeller 5 from the upper end portion of the scroll portion 7A. 5 is arranged so as to project in an arch shape on the front side. At this time, the longitudinal direction of the design panel 2 and the scroll portion 7 </ b> A is arranged in parallel to the axial direction of the impeller 5. The impeller 5 is disposed so as to be rotatable around an axis. Although not shown in detail, the outer peripheral surface of the impeller 5 is composed of blades provided at a predetermined pitch in the circumferential direction. Moreover, the suction inlet 2a is formed in the front and upper surfaces of the design panel 2 in the shape of a rail. Hereinafter, the axial direction of the impeller 5 is simply referred to as the axial direction.

  The stabilizer 8 is disposed so as to protrude from the front end of the design panel 2 protruding from the scroll portion 7A toward the impeller 5 so as to face the lower wall surface of the scroll portion 7A. Moreover, the side wall board 9 is attached so that the opening of the axial direction both sides formed of 7 A of scroll parts, the design panel 2, and the stabilizer 8 may be covered. An opening surrounded by the lower ends of the scroll portion 7 </ b> A, the design panel 2, and the side wall plate 9 constitutes the air outlet 11.

  Furthermore, the ventilation path 10 which leads from the suction inlet 2a to the blower outlet 11 is formed in the space formed by the scroll portion 7A, the stabilizer 8, the design panel 2, and the side wall plate 9. Further, the heat exchanger 3 is disposed in the ventilation path 10 on the suction port 2a side (upstream side) of the impeller 5 so as to cover the impeller 5 in an inverted V shape.

  In the air conditioner 1 </ b> A configured as described above, when the impeller 5 is rotated, air is sucked from the suction port 2 a, passes through the heat exchanger 3, and flows through the impeller 5. At this time, the upper end of the scroll part 7A is extended to the suction port 2a side of the impeller 5, and the airflow is guided behind the impeller 5 by the scroll part 7A. Further, the airflow passes through a portion of the ventilation path 10 formed between the scroll portion 7A and the stabilizer 8 facing each other and is discharged into the room from the air outlet 11. That is, the wall surface of the scroll portion 7 </ b> A on the side of the ventilation path 10 (hereinafter referred to as the guide wall surface 7 a) guides the airflow from the rear of the impeller 5 to the air outlet 11.

  Next, the shape of the wall surface on the ventilation path 10 side in the scroll portion 7A will be described with reference to FIGS. In addition, in FIG. 1, the cross section perpendicular | vertical to the axial direction of the impeller 5 of the air conditioner 1A in the intermediate position of an axial direction is shown with a broken line, and also the air conditioner 1A in the position of the one end part of an axial direction is shown. The scroll portion 7A in the side cross section of the impeller 5 is also shown by a solid line. Moreover, in FIG. 2, the site | part of the scroll part 7A in the intermediate position of the longitudinal direction (axial direction) of the scroll part 7A is shown with the broken line.

  1 and 2, the guide wall surface 7a has a wall surface with a cross section perpendicular to the axial direction, and has a smooth curve that protrudes outwardly from the ventilation path 10 that continues from the rear of the impeller 5 to the air outlet 11. Yes. Moreover, the height of the edge part by the side of the blower outlet 11 of the guide wall surface 7a is the same over the axial direction. Furthermore, the distance between the guide wall surface 7a and the shaft center of the impeller 5 becomes longer as it approaches the outlet 11.

  In addition, the guide wall surface 7a has a cross section orthogonal to the airflow direction in which the amount of protrusion to the outside of the ventilation path 10 gradually decreases from the axial center portion indicated by the broken line toward both axial end portions indicated by the solid line. The wall surface shape is formed so as to continue from the rear of the impeller 5 to the vicinity of the end on the outlet 11 side. That is, when the guide wall surface 7a compares the size of the air passage area in the cross section perpendicular to the axial direction while shifting the position in the axial direction, the air passage in the cross section including the center in the axial direction of the scroll portion 7A. It is formed so as to maximize the area.

Furthermore, the guide wall surface 7a has a difference in the amount of protrusion of the cross section of the ventilation path 10 perpendicular to the airflow direction to the outside of the ventilation path 10 between the axial center and both ends from the vicinity of the outlet 11 side end. It is formed so as to be gradually reduced as it goes to and connected to the lower end portion of the air outlet 11 formed at the same height in the axial direction.
Hereinafter, the cross section of the ventilation path 10 orthogonal to the airflow direction will be described as the ventilation path cross section, and the cross section perpendicular to the axial direction will be described as the ventilation path side section.

  Thus, the guide wall surface 7a of the air conditioner 1A is formed by a curved surface that continues from the back of the impeller 5 to the end on the outlet 11 side, and the height of the end on the outlet 11 side is high. It is the same over the axial direction, and the wall surface of the stabilizer 8 and the wall surface of the side wall plate 9 facing the guide wall surface 7a are formed flat. Therefore, the airflow flowing through the impeller 5 reaches the air outlet 11 smoothly without disturbing the flow, and the angle of the airflow discharged from the air outlet 11 is constant over the axial direction.

  Moreover, the ventilation path area in a ventilation path side cross section becomes larger in the axial center part side than the axial both ends. And the dynamic pressure of the airflow increased when flowing through the impeller 5 is converted to a larger static pressure at the central portion where the ventilation path area is larger than at both ends where the ventilation path area is small. Accordingly, in the ventilation path 10, a force that is directed from the central portion to both ends acts on the airflow due to the difference in static pressure between the central portion in the axial direction and both ends.

Here, the result of having measured the air volume distribution of the airflow discharged | emitted from the blower outlet 11 of 1 A of air conditioners is shown in FIG.
In FIG. 3, the air volume and direction of each airflow passing through a predetermined portion in the axial direction at the air outlet 11 are visually represented by a straight line with an arrow having a length proportional to the magnitude of the airflow. When the arrow is pointing downward, the airflow is released into the room from the air outlet 11. And as FIG. 3 showed, it was confirmed that the airflow is discharged | emitted indoors by the substantially uniform air volume distribution over the whole area of the axial direction of the blower outlet 11. As shown in FIG.

Consider the above measurement results.
First, in general, the amount of air flowing through the impeller 5 decreases at both ends of the impeller 5 in the axial direction. However, as described above, in the ventilation path 10 of the air conditioner 1A, the force that is directed from the central part to both ends acts on the airflow due to the difference in the static pressure between the central part and both ends in the axial direction. As a result, in the ventilation path 10 on the downstream side of the impeller 5, the air volume at both ends in the axial direction is increased so as to compensate for the decrease in the air volume of the air stream immediately after the impeller 5 flows through. Therefore, in the ventilation path 10, the air volume of the airflow is made uniform over the axial direction. Further, since there is no wall surface protruding to the air outlet 11 so as to block the air current, the air current reaching the air outlet 11 is released without reconverting the static pressure so as to increase the dynamic pressure at the air outlet 11. . From the above, it is determined that the air volume distribution of the airflow discharged from the outlet 11 is substantially uniform over the entire area in the axial direction.

Here, the air conditioner of the comparative example in which the guide wall surface of the scroll part is formed flat over the entire axial direction is prepared, and the filter of the suction port 2a is clogged with dust attached over time. FIG. 4 shows the results of measuring the air volume distribution of the airflow discharged from the outlet 11 for.
Although not shown, when the air volume distribution of the airflow discharged from the outlet 11 is measured for the air conditioner of the comparative example in which the filter of the inlet 2a is not clogged, both ends in the axial direction of the outlet 11 are measured. It was confirmed that the air volume decreased toward the side.

In FIG. 4, as in FIG. 3, the flow rate and direction of the airflow passing through a predetermined position in the axial direction of the air outlet 11 are visually indicated by a straight line with an arrow having a length proportional to the magnitude of the flow rate of the airflow. It is represented. When the length of the line segment is 0, the airflow of the airflow is 0, and when the arrow is downward, the airflow is discharged into the room from the air outlet 11, and when the arrow is upward, the airflow is blown. The state which is flowing backward in the ventilation path 10 from the exit 11 is represented.
In the air conditioner of the comparative example, as shown in FIG. 4, it was confirmed that the air current flows backward into the ventilation path 10 at both ends in the axial direction of the air outlet 11.

Next, the above results will be considered.
As described above, the amount of airflow discharged from both ends of the blower outlet 11 in the axial direction is reduced even when the filter of the suction inlet 2a is not clogged. In addition to this, when the filter of the suction port 2a is clogged and the pressure loss at the suction port 2a becomes large, the force to release the airflow from the outlet 11 becomes weaker, and both axial ends of the outlet 11 become smaller. Then, it is determined that the airflow flows backward and enters the ventilation path 10.

  On the other hand, in the air conditioner 1A, even if clogging occurs at the suction port 2a, the air volume increases at both ends in the axial direction of the air outlet 11 as described above. It is possible to suppress as much as possible that the air current flows backward from the end of the direction and enters the ventilation path 10.

Next, in the air conditioner 1A, a result of measuring the power consumption when the amount of protrusion of the guide wall surface 7a to the outside of the ventilation path 10 is changed will be specifically described.
Here, the distance between one end or the other end (end portion) of the guide wall surface 7a intersecting with the plane including the axis of the impeller 5 and the axis of the impeller 5 is a first length, and the plane is The distance between the central portion of the intersecting guide wall surface 7a in the axial direction and the axis of the impeller 5 is the second length. When the difference between the first length and the second length is α, as shown in FIG. 1, the plane including the axial center of the impeller 5 extends from the portion behind the impeller 5 on the guide wall surface 7 a to the outlet. When the plane is rotated around the axis of the impeller 5 so as to intersect with the entire region reaching the end on the 11 side, the maximum value of the difference α obtained for each rotation angle of the plane is the maximum wall surface. The distance δ is assumed. Further, as shown in FIG. 2, the length of the scroll portion 7A in the axial direction is defined as a scroll portion length L.

And consumption of the air conditioner 1A when the scroll portion 7A is deformed and the maximum distance δ between the wall surfaces is changed so that the intermediate portion of the axial length of the scroll portion 7A protrudes most outside the ventilation path 10 The electric power was measured using the maximum distance between wall surfaces δ / the length L of the scroll portion as a parameter. Note that the scroll portion length L is constant. For comparison, power consumption was also measured for a comparative air conditioner (not shown) having a scroll portion with a maximum inter-wall distance δ of 0. Hereinafter, the maximum inter-wall surface distance δ / the scroll portion length L is simply δ / L.
The power consumption of the air conditioner 1A was measured by changing δ / L from 0 to 0.02. FIG. 5 shows the power consumption of the air conditioner 1A when the power consumption of the air conditioner of the comparative example is 100.
As shown in FIG. 5, the power consumption of the air conditioner 1 </ b> A is δ / L compared to the power consumption of the air conditioner of the comparative example in which the guide wall surface is flat (δ / L = 0). It became smaller in the whole range.

  Further, when δ / L was continuously changed, the power consumption became a characteristic that continuously changed in a downwardly convex shape. When the value of δ / L was increased from 0 to around 0.002, the power consumption gradually decreased, and when δ / L was further increased, the power consumption decreased rapidly. Further, when δ / L is in the range of 0.003 ≦ δ / L ≦ 0.01, the power consumption has changed to a substantially minimum value. When δ / L is in the range of 0.003 ≦ δ / L ≦ 0.01, the power consumption is reduced by about 7% compared to when δ / L is 0. Further, when the value of δ / L becomes larger than 0.01, the power consumption increases again, but the power consumption does not become larger than that when δ / L is 0 in the measurement range.

Next, the above results will be considered.
At any value where δ / L is larger than 0, the ventilation path area in the cross section of the ventilation path is larger than that when δ / L is 0 except for both axial ends of the guide wall surface 7a. Therefore, in the air conditioner 1A in which the cross section of the ventilation path at each position in the axial direction is large, the dynamic pressure in the ventilation path 10 is reduced as compared with the air conditioner of the comparative example. Thereby, in the air conditioner 1A, it is determined that the dynamic pressure loss of the blown airflow is suppressed, and the power consumption is reduced with respect to the air conditioner of the comparative example.

  Further, as δ / L increases, the wall surface shape of the guide wall 7a in the cross section on the side of the ventilation path protrudes greatly outside the ventilation path 10 and the area of the ventilation path in the cross section of the ventilation path increases. The speed is slow. In particular, the guide wall surface 7a in the cross section on the ventilation path side is greatly protruded on the axial center side of the guide wall surface 7a. When a slow-velocity airflow passes through the portion of the guide wall surface 7a protruding to some extent, the airflow cannot follow the shape change of the guide wall surface 7a along the airflow direction, and a part of the airflow is separated from the guide wall surface 7a. The In the vicinity where the air current is peeled off from the guide wall surface 7a, the air current is disturbed and becomes a factor of increasing power consumption.

In view of the above, when δ / L is in the range of 0 <δ / L ≦ 0.0015, the protruding amount of the guide wall surface 7a is small, and there is almost no air flow separated from the guide wall surface 7a, but at each position in the axial direction. Since the increase amount of the ventilation path area in the cross section of the ventilation path is small, it is determined that the effect of reducing the power consumption due to the increase of the ventilation path area does not appear greatly.
When δ / L is further increased from 0.0015 to 0.003, the air flow separated from the guide wall surface 7a is small, while the air passage area of the air passage side cross-section at each position in the axial direction is small. Will increase. Therefore, as δ / L increases, it is determined that the effect of reducing power consumption gradually appears and the power consumption is reduced with respect to the air conditioner of the comparative example.

Since the amount of separation of the airflow from the guide wall surface 7a starts to increase before δ / L is 0.003, the power consumption is increased due to the separation of the airflow from the guide wall surface 7a. Thereby, the reduction amount of power consumption becomes small with respect to the increase of δ / L.
When δ / L is 0.003 or more, the reduction in power consumption due to the increase in the ventilation path area of the ventilation path side cross section at each position in the axial direction and the airflow is separated from the guide wall surface 7a. The resulting increase in power consumption cancels out, and it is determined that a decrease in power consumption accompanying an increase in δ / L is suppressed. Thereafter, until δ / L reaches 0.01, the reduction in power consumption due to the increase in the ventilation path area of the ventilation path side cross section at each axial position, and the airflow is separated from the guide wall surface 7a. It is determined that the amount of increase in power consumption due to this cancels out and the power consumption remains at the minimum value.

  Further, when δ / L is larger than 0.01, the air passage area is larger than the reduction amount of power consumption caused by the air passage area of the air passage side cross section at each axial position is increased. It becomes larger than the increase amount of power consumption. Further, as δ / L is larger, the rate of change in the increase in power consumption due to the airflow being peeled from the guide wall surface 7a is the change in the reduction in power consumption due to the increase in the ventilation path area. Will be greater than Thus, when δ / L is greater than 0.01, it is determined that the effect of reducing power consumption is gradually reduced.

According to the first embodiment, the guide wall surface 7a has a smooth curved curve with the wall surface shape of the cross section on the side of the ventilation path protruding outward from the ventilation path 10 continuing from the rear of the impeller 5 to the outlet 11. .
Further, the guide wall surface 7a blows the wall surface shape of the ventilation path cross section from the rear side of the impeller 5 so that the amount of protrusion to the outside of the ventilation path 10 gradually decreases from the central part in the axial direction toward both end parts in the axial direction. It is formed so as to continue to the vicinity of the end on the outlet 11 side. Furthermore, the guide wall surface 7a gradually reduces the difference in the amount of protrusion of the air passage cross section from the vicinity of the air outlet 11 side end portion toward the air outlet 11 to the outside of the air passage 10 at the axial center and both ends of the air passage. It is formed so that it may connect with the edge part of the blower outlet 11 formed in the same height over the axial direction.

  Therefore, the air volume fluctuation and the pressure fluctuation in the cross section on the ventilation path side do not change discontinuously in the axial direction and change continuously. As a result, the simultaneity of the air volume fluctuation and the pressure fluctuation is greatly weakened in the axial direction of the cross flow fan, and the effect of suppressing the generation of discrete frequency noise is maximized. Furthermore, since the airflow flowing through the impeller 5 smoothly flows through the ventilation path 10 and reaches the outlet 11 side, turbulent airflow is not generated and an increase in broadband noise can be suppressed. Moreover, since the static pressure of airflow is not reconverted by the blower outlet 11 conventionally, the power efficiency of 1 A of air conditioners can be improved.

  Moreover, in the ventilation path 10, since the force which goes to both ends from a center part acts on an airflow by the difference of the static pressure of the center part of an axial direction and both ends, the air volume of an airflow is equalized over an axial direction. Furthermore, the blower outlet 11 is formed in the same height over the axial direction. Therefore, the air conditioner 1A is generally provided with upper and lower flaps (not shown) for controlling the blowing angle of the airflow discharged from the blower outlet 11 into the room. Since the effect of the upper and lower flaps for controlling the air pressure acts uniformly over the axial direction of the air outlet 11, good air flow controllability by the upper and lower flaps can be expected.

  Moreover, the wall surface shape of the guide wall surface 7a further improves the power efficiency of the air conditioner 1A by forming δ / L of the scroll portion 7A in a range of 0.003 ≦ δ / L ≦ 0.01. it can.

Furthermore, since the air passage area in the cross section of the air passage is enlarged at the center in the axial direction of the air passage 10, the air flow does not flow backward from the end of the air outlet 11 in the axial direction and enters the air passage 10. An effect is also obtained.
That is, in the air conditioner of the comparative example in which the guide wall surface of the scroll portion is flat, when the suction port 2a is clogged and the pressure loss of the suction port 2a becomes large, as shown in FIG. A backflow of airflow occurs. That is, external air easily flows into the air conditioner of the comparative example at both ends of the air outlet 11 where the air volume of the airflow is small. When the airflow flows backward into the ventilation path 10, the following problem occurs. When the air conditioner of the comparative example is performing a cooling operation, if warm indoor air flows backward into the ventilation path 10, the warm air is cooled by the heat exchanger 3 and condensation occurs in the heat exchanger 3. When this dew condensation becomes large, water droplets are dripped from the air outlet 11 by the wind power of the impeller 5.

  On the other hand, in the air conditioner 1A, in the ventilation path 10 between the downstream of the impeller 5 and the blower outlet 11, due to the difference in static pressure between the central portion and both end portions in the axial direction of the scroll portion 7A, both end portions are arranged from the center portion. A force is directed to the airflow. For this reason, even if the pressure loss of the suction port 2a increases due to clogging of the suction port 2a, the air volume at both ends in the axial direction of the air outlet 11 is close to the air volume at the central portion in the axial direction. Since it increases, it can prevent that an airflow flows backward into the ventilation path 10 from the blower outlet 11. FIG.

Embodiment 2. FIG.
FIG. 6 is a perspective view showing a state in which a drive motor is connected to a crossflow fan of an air conditioner according to Embodiment 2 of the present invention, and FIG. 7 is a diagram (scroll in the air conditioner according to Embodiment 2 of the present invention. It is a figure which shows the relationship between the length x) between one end of the part 7B and the side cross-section maximum position / scroll part length L, and power consumption. In FIG. 6, the same or corresponding parts as those in the first embodiment are given the same reference numerals, and the description thereof is omitted.
Further, in FIG. 6, the position in the axial direction of the scroll portion where the ventilation path area in the ventilation path side cross section is maximized is indicated by a broken line.

In FIG. 6, the air conditioner 1 </ b> B has a curved surface in which the wall surface of the scroll portion 7 </ b> B on the side of the ventilation path 10 (hereinafter referred to as a guide wall surface 7 b) has a convex shape on the outside of the ventilation path 10. Furthermore, the height of the end portion on the air outlet 11 side is the same over the axial direction.

  In addition, the guide wall surface 7b has a wall surface shape in the cross section of the air passage where the amount of protrusion to the outside of the air passage 10 gradually decreases from a predetermined position in the axial direction of the impeller 5 of the guide wall surface 7b toward both ends. It is formed so that it may continue from the back of this to the vicinity of the end on the outlet 11 side. At this time, the predetermined portion is shifted by a predetermined distance toward one end side in the axial direction with respect to the intermediate portion in the axial direction of the guide wall surface 7b.

That is, the guide wall surface 7b includes at least a predetermined portion on one end side from the center in the axial direction of the scroll portion 7B when comparing the size of the ventilation path area in the cross section of the ventilation path with the position shifted in the axial direction. It forms so that the ventilation path area in a ventilation path side cross section may become the maximum.
As a result, the inclination in the axial direction on one end side of the guide wall surface 7b becomes steeper compared to the guide wall surface 7a formed so that the ventilation path area of the cross section on the ventilation path side is maximized in the central portion of the scroll portion 7A in the axial direction. . Hereinafter, the position in the axial direction of the predetermined part of the guide wall surface 7b where the ventilation path area in the ventilation path side cross section is maximum is defined as the maximum side cross section position.

  Further, in the guide wall surface 7b, the difference between the maximum position of the side cross section in the cross section of the ventilation path and the amount of protrusion of the both end portions to the outside of the ventilation path 10 is gradually reduced from the vicinity of the air outlet 11 side end toward the air outlet 11. It forms so that it may connect with the edge part of the blower outlet 11 formed in the same height over the axial direction.

The impeller 5 has a side wall 5a that closes an opening at one end in the axial direction. Further, an insertion hole 5b is formed in the side wall 5a coaxially with the shaft of the impeller 5.
A drive motor 13 that supplies a driving force for rotating the impeller 5 about its axis is disposed outside the impeller 5 so as to face the outer surface of one side wall 5 a of the impeller 5. Further, one end of the connecting shaft 14 is connected to the drive motor 13, and the connecting shaft 14 rotates around the shaft by the driving force of the driving motor 13.

And the fan boss | hub 16 protrudes in the inner side of one side wall 5a, making the hole center correspond to the hole center of the penetration hole 5b.
The other end of the connecting shaft 14 inserted through the insertion hole 5 b of the side wall 5 a is inserted into the hole of the fan boss 16 and fixed to the fan boss 16. At this time, the connecting shaft 14 is disposed coaxially with the impeller 5.
Other configurations are the same as those in the first embodiment.

The impeller 5 to which the connecting shaft 14 is connected as described above rotates in conjunction with the rotation around the connecting shaft 14 that is rotated by the driving force of the drive motor 13.
In FIG. 6, the impeller 5 is illustrated in a cylindrical shape in which the opening is closed by the side wall 5 a, but the impeller 5 is disposed on the outer peripheral surface of the impeller 5 at a predetermined pitch in the circumferential direction (not illustrated). The root of (z) is arranged at a position that enters a predetermined distance from the outer peripheral surface of the impeller 5 to the axial center side of the impeller 5 in the radial direction.

Hereinafter, an effect obtained by forming the guide wall surface 7b so that the maximum position of the side cross section is shifted from the central portion in the axial direction of the guide wall surface 7b to one end side (fan boss 16 side) will be described.
When the connection between the connecting shaft 14 and the impeller 5 is performed using the fan boss 16 fixed to the inner surface of the side wall 5a as described above, the end of the impeller 5 on the fan boss 16 side in the axial direction. In the vicinity, the airflow resistance when the airflow flows through the impeller 5 is increased by the fan boss 16. Further, in the vicinity of the end portion of the impeller 5 on the fan boss 16 side, the blade may be omitted in order to facilitate the connecting operation with the connecting shaft 14. Thereby, the air volume of the airflow immediately after flowing through the impeller 5 is particularly reduced on the fan boss 16 side of the impeller 5.

  However, since the guide wall surface 7b is formed such that the maximum position of the side cross section is disposed on one end side in the axial direction of the guide wall surface 7b, when the maximum position of the side cross section is in the central portion of the guide wall surface 7b in the axial direction. In comparison, the air passage area in the vicinity of one end in the axial direction in the air passage side section is increased. Thereby, in the vicinity of one end of the ventilation path 10 in the axial direction, the ventilation resistance is smaller than in the vicinity of the other end, and the air volume is increased. Further, in the ventilation path 10, in the axial direction, a force directed from the side cross-section maximum position to both ends due to the difference in the static pressure between the side cross-section maximum position and both ends also acts on the airflow.

  In this way, the guide wall 7b compensates for the shortage of the airflow flowing through one end of the impeller 5 due to the fan boss 16 being disposed on the inner surface of the side wall 5a of the impeller 5, and the ventilation path 10 It is formed so as to increase the air volume at one end side in the axial direction. That is, in the ventilation path 10, the air volume of the airflow is made uniform over the axial direction. Note that the area of the ventilation path near the other end in the axial direction in the cross section on the side of the ventilation path is reduced, but the force directed from the maximum position in the side section to both ends remains due to the difference in static pressure between the maximum position in the side section and both ends in the axial direction. ing. Therefore, the effect of making the air volume of the ventilation path 10 uniform is not impaired.

Here, when the airflow of the airflow in the ventilation path 10 is uniform over the axial direction, the airflow distribution of the airflow in the axial direction is also uniform, and the airflow distribution of the airflow in the axial direction of the ventilation path 10 is not uniform. When uniform, the wind speed distribution of the airflow in the axial direction is also nonuniform.
For this reason, when the airflow of the same air volume is discharged into the room from the air outlet 11, the wind speed of the air current when the air volume distribution is uniform is larger than the maximum value of the wind speed in the air speed distribution of the air current when the air volume distribution is non-uniform. Get smaller. That is, since the load of the drive motor 13 is reduced by the amount that the wind speed can be reduced when the air volume distribution is uniform than when the air volume distribution is non-uniform, the power consumption of the air conditioner 1B is maximized in the side section. The position is reduced from the power consumption of the air conditioner at the axial center of the guide wall surface 7b. Hereinafter, the reduction of power consumption caused by moving the maximum position of the side cross section toward the fan boss 16 to make the air flow uniform will be referred to as power consumption caused by the uniform air flow.

Next, since the effect of having the configuration of the present embodiment was confirmed by a test, the contents thereof will be specifically described below.
Here, the length in the axial direction between one end of the scroll portion 7B and the maximum position in the side cross section is x. Hereinafter, (length x between one end of scroll part 7B and the side cross-section maximum position) / (scroll part length L) is simply referred to as x / L.

  The power consumption of the air conditioner 1B was measured by changing x / L from a value in the vicinity of 0.5 (<0.5) to 0.1 with x / L as a parameter. At this time, L was kept constant, and the power consumption was measured by gradually moving the maximum position of the side cross section from the central side in the axial direction of the guide wall surface 7b to one end side. Moreover, the power consumption of the air conditioner whose x / L is 0.5 was also measured. And the power consumption of the air conditioner 1B when the power consumption of the air conditioner whose x / L is 0.5 is set to 100 is shown in FIG.

  As shown in FIG. 7, when x / L is continuously changed from 0.5 to 0.1, the power consumption of the air conditioner 1B continuously changes in a downwardly convex shape. became. When x / L is in the range of 0.16 <x / L <0.5, the power consumption of the air conditioner 1B is lower than the power consumption of the air conditioner having x / L of 0.5. Especially, when x / L is in the range of 0.27 ≦ x / L ≦ 0.31, the power consumption of the air conditioner 1B changes at a substantially minimum value, and the power consumption at this time is x / L It was about 2% lower than the power consumption of the air conditioner with 0.5.

Consider the above measurement results.
When x / L is gradually decreased from 0.5 to 0.31, the effect of uniforming the air volume distribution increases as the value of x / L decreases, so the power consumption is 0.31 at x / L. It is judged that it decreases as it approaches. However, when x / L becomes 0.31, it is determined that some turbulence of airflow is induced because the maximum position of the side cross section is too close to the fan boss 16. This turbulence of the air current becomes a factor that increases the power consumption of the air conditioner 1B. Hereinafter, the increase in the power consumption of the air conditioner 1B due to the fact that the maximum position of the side cross section is too close to the fan boss 16 is referred to as an increase in the power consumption due to the turbulence of the airflow.

  That is, when x / L is between 0.27 ≦ x / L ≦ 0.31, the smaller the x / L, the greater the reduction in power consumption due to air flow uniformity, but it is due to air flow turbulence. Therefore, it is determined that the total power consumption of the air conditioner 1B is maintained at a substantially minimum value.

  As x / L is further reduced from 0.27, the increase in power consumption due to airflow turbulence becomes more dominant than the reduction in power consumption due to airflow uniformity, and x / L is small. It is determined that the power consumption increases. Then, when x / L becomes 0.16, the power consumption becomes the same value as the power consumption when x / L = 0.5.

  According to this second embodiment, in the air conditioner 1B, the wall surface shape of the guide wall surface 7b of the scroll portion 7B in the cross section of the ventilation path is a convex curve on the outside of the ventilation path 10, and further on the outlet 11 side. The heights of the end portions are the same in the axial direction. Further, the guide wall surface 7b has a wall surface shape of the cross section of the ventilation path in which the amount of protrusion to the outside of the ventilation path 10 gradually decreases from the maximum position in the side section toward both ends in the axial direction. It is formed so as to continue to the vicinity of the end on the 11th side. At this time, the guide wall surface 7b is formed so that the maximum position of the side cross section x / L satisfies 0.16 <x / L <0.5.

  Since the connection between the connecting shaft 14 and the impeller 5 is performed using the fan boss 16 fixed to the inner surface of the side wall 5a, the airflow flowing through the impeller 5 is the end portion on the fan boss 16 side. Decrease nearby. However, since the guide wall surface 7b is formed so that the maximum position of the side cross section x / L satisfies 0.16 <x / L <0.5, in the ventilation path 10 downstream of the impeller 5, The ventilation path area in the ventilation path side cross section in the vicinity of the end on the fan boss 16 side in the axial direction increases. Therefore, the air volume in the vicinity of the end on the fan boss 16 side increases. Thereby, in the ventilation path 10 on the downstream side of the impeller 5, the shortage of the air volume on one end side in the axial direction of the impeller 5 of the airflow flowing through the impeller 5 is compensated. Thereby, since the air volume of the airflow is made uniform throughout the ventilation path 10, it is possible to improve the power efficiency of the air conditioner 1B while preventing the airflow from flowing back into the ventilation path 10 from the air outlet 11. it can. Furthermore, the effect of improving the power efficiency of the air conditioner 1B can be maximized by setting x / L to 0.27 ≦ x / L ≦ 0.31.

It is a sectional side view of the air conditioner which concerns on Embodiment 1 of this invention. It is a perspective view of the scroll part of the air conditioner concerning Embodiment 1 of this invention. It is a figure showing the air volume and direction of the airflow in the blower outlet of the air conditioner which concerns on Embodiment 1 of this invention. It is a figure showing the air volume and direction of the airflow in the blower outlet of the air conditioner of a comparative example. It is a figure which shows the relationship between the largest wall surface distance (delta) / scroll part length L, and power consumption in the air conditioner which concerns on Embodiment 1 of this invention. It is a perspective view which shows the state by which the drive motor was connected with the crossflow fan of the air conditioner which concerns on Embodiment 2 of this invention. It is a figure which shows the relationship between (length x between the end of the scroll part 7B and the side cross-section maximum position) / scroll part length L, and power consumption in the air conditioner which concerns on Embodiment 2 of this invention.

Explanation of symbols

  1A, 1B Air conditioner, 4 Cross flow fan, 5 impeller, 7a, 7b Guide wall surface, 7A, 7B Scroll part, 10 Ventilation path, 11 Air outlet, 13 Drive motor, 14 Connecting shaft, 16 Fan boss.

Claims (4)

In an air conditioner including a cross flow fan having a scroll portion having a guide wall that constitutes an impeller and a ventilation path and guides an air flow from the back of the impeller to an air outlet,
The guide wall has an end portion on the outlet side that is formed at the same height over the entire area in the axial direction of the impeller, and has a wall surface shape in a cross section perpendicular to the axial direction of the impeller. The wall surface shape in a cross section orthogonal to the airflow direction which is convex outward and the amount of protrusion to the outside of the ventilation passage gradually decreases from the central part of the impeller toward the both ends is defined by the impeller Continue from the back to the vicinity of the end on the outlet side, and then gradually reduce the difference in the amount of protrusion to the outside of the ventilation path in the axial direction of the impeller toward the outlet side in the airflow direction. An air conditioner comprising a curved surface connected to an end portion on the outlet side formed at the same height over the entire region in the axial direction of the vehicle.   The guide wall surface has a length in the axial direction of the impeller of the guide wall as L, and an end of the guide wall surface in a plane including an axis of the impeller intersecting the guide wall surface and the impeller The difference between the distance between the shaft center and the distance between the central portion of the guide wall surface in the axial direction of the impeller and the shaft center of the impeller is α, and the flat surface is the impeller of the guide wall surface. When the plane is rotated around the axis of the impeller so as to intersect with the entire area from the rear part to the end on the outlet side, the above-mentioned obtained at each rotation angle of the plane 2. The air conditioner according to claim 1, wherein the air conditioner is formed so as to satisfy 0.003 ≦ δ / L ≦ 0.01, where δ is a maximum value of α. An impeller and a cross-flow fan having a scroll portion having a guide wall surface for guiding an air flow from the rear side of the impeller to the air outlet, and an inner side of a side wall on one end side of the impeller A fan boss, a tip of which is inserted into the side wall of the impeller and disposed inside the impeller, fixed to the fan boss coaxially with the impeller, and connected to the connecting shaft outside the impeller. In an air conditioner comprising: a drive motor that is coupled and generates a driving force that rotates the coupling shaft about the axis;
The guide wall has an end portion on the outlet side that is formed at the same height over the entire area in the axial direction of the impeller, and has a wall surface shape in a cross section perpendicular to the axial direction of the impeller. The wall surface shape in a cross section orthogonal to the airflow direction that is convex outward and the amount of protrusion to the outside of the ventilation path gradually decreases from a predetermined portion of the guide wall surface in the axial direction of the impeller toward both ends, Continue from the rear of the impeller to the vicinity of the end on the outlet side, and then gradually reduce the difference in the amount of protrusion to the outside of the ventilation path in the axial direction toward the outlet side in the airflow direction. It is composed of a curved surface connected to the end on the outlet side formed at the same height over the entire area in the axial direction of the car, and further, the length of the guide wall in the axial direction of the impeller is L, Axial length between one end of the guide wall and the predetermined part When the the x, air conditioner, characterized in that it is formed so as to satisfy 0.16 <x / L <0.5.   4. The air conditioner according to claim 3, wherein the x / L is in a range of 0.27 ≦ x / L ≦ 0.31.

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