JPH1183062A - Indoor unit for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate generation of a singular sound of a low frequency by forming an outlet angle of an airfoil blade to a specific value or less, thereby obtaining a diffusing performance of a large air volume. SOLUTION: An impeller is driven by an electric motor to boost an air flow. Then, the air is supplied to a diffusing air duct enlarged at an air outlet side formed in a tapered state of a predetermined angle via a straight line. A wind direction is controlled by upper and lower flaps, and the air is diffused into a room. In this case, an outlet angle β2 is set to 18 deg. or more. Thus, an air volume ratio at the time of the same noise can be increased. An outlet angle β2 is set to 23 deg. or less. Thus, a singular sound of a low frequency can be reduced. Thus, diffusing performance of large air volume is obtained, and the indoor unit for the air conditioner in which generation of the singular sound of the low frequency is reduced can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoor unit of an air conditioner provided with a once-through blower and performing a blowing operation.

[0002]

2. Description of the Related Art FIGS.
No. 88 is a view showing an indoor unit of an air conditioner similar to the indoor unit of a conventional air conditioner, FIG. 5 is a cross-sectional side view of the indoor unit of the air conditioner, and FIG. FIG. 7 is a right side view of FIG. 6, and FIG. 8 is an enlarged view of a blade of FIG. In the figure,
Reference numeral 1 denotes a box of an indoor unit of a separation type air conditioner installed indoors (not shown), which is provided with a once-through blower.

[0003] Reference numeral 2 denotes an impeller of a once-through blower, a circular support plate 3 which is arranged apart from each other along the rotation axis of the impeller 2 and is provided concentrically with the rotation axis, and a support plate 3 having an arc-shaped cross section. And a plurality of wing blades 4 arranged annularly apart from each other near the outer edge of the support plate 3 and have a diameter D shown in FIG.

Reference numeral 5 denotes a rear casing provided on the back side of the box 1 of the impeller 2, 6 denotes a front casing provided near the front of the box 1 of the impeller 2, and 7 denotes a space between the rear casing 5 and the front casing 6. The formed blowing air path, 8 are upper and lower flaps provided at the outlet of the blowing air path 7, and 9 is a heat exchanger arranged on the upstream side of the once-through blower.

[0005] In FIG. 8, A is an outer peripheral side mounting end of the blade 4 on the support plate 3 in a cross section of the impeller 2,
Is the inner peripheral side mounting end of the blade 4 with respect to the support plate 3 in the cross section of the impeller 2, O ₀ is the rotation center of the impeller 2, O ₁ is the center of the circular arc in the cross section of the blade 4, and t _max is the blade. Feather 4
, _Tmin is the thickness of the portion of the outer peripheral side mounting end of the blade 4 excluding the round shape.

[0006] Further, O ₀ A is the outer peripheral side mounting end A of the blade 4.
Is a _first straight line connecting the rotation center O _{0 of the} impeller 2, O ₁ A is a second straight line connecting the outer peripheral side mounting end A of the blade 4 and the center O ₁ of the cross-sectional arc of the blade 4, and n is the A first perpendicular line at the outer peripheral side mounting end A of the straight line O ₀ A, m is a second perpendicular line at the outer peripheral side mounting end A of the second straight line O ₁ A, and β ₂ is an angle between the first perpendicular line n and the second perpendicular line m. The blade exit angle, l, is the center line in the thickness direction of the cross section of the blade 4.

[0007] The conventional air conditioner indoor unit is configured as described above, and the impeller 2 is driven and rotated by an electric motor (not shown) to apply energy to the air to increase the pressure of the blast. Then, the air is blown into a blowing air path 7 which is formed in a tapered shape having a constant angle by a straight line and has a widened outlet side, and a pressurized air flow is guided to the upper and lower flaps 8 from the outlet.
The wind direction is controlled by this and is blown into the room. Thereby, an air conditioning operation is performed.

[0008]

In the conventional air conditioner indoor unit as described above, when a large air volume is required and noise needs to be reduced, the diameter D of the impeller 2 is increased. Thereby, the blowing performance is improved. Then, the blade outlet angle β _{2 at} this time is set to 24 ° or more. But,
When the ratio of the inner peripheral side mounting end B diameter O ₀ B to the outer peripheral side mounting end A diameter O ₀ A of the blade blade 4 is constant and the blade outlet angle β ₂ is kept constant, the diameter D of the impeller 2 is increased. Although the air volume at the rotation speed increases, a low frequency peculiar sound is generated.

This peculiar sound is a sound in the vicinity of 170 Hz to 230 Hz and is easily generated when the blade outlet angle β ₂ is 24 ° or more, though it depends on the wind speed distribution on the suction side.
Then, when such a low frequency peculiar sound is generated, there is a problem that, when compared at the same air volume, the noise value increases and the audibility deteriorates.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide an indoor unit of an air conditioner which can provide a large air volume blowing performance and generates low frequency peculiar sounds. And

[0011]

In an indoor unit of an air conditioner according to the present invention, an impeller which is disposed in a box body and constitutes a once-through blower, and a rotation axis of the impeller which constitutes a main part of the impeller. A circular support plate which is arranged apart from each other with the plate surfaces facing each other and is provided concentrically with the rotation axis, and the other main portion of the impeller is formed in an arcuate cross-section and has a circular cross section. A plurality of which are mounted annularly apart from each other with their arc surfaces facing each other near the outer edge of the support plate, and the outer periphery of a first straight line connecting the outer peripheral mounting end in the cross section of the impeller and the rotation center of the impeller. The blade exit angle formed by the second perpendicular at the outer mounting end of the second straight line connecting the center of the first perpendicular and the cross-sectional circular arc to the outer mounting end at the side mounting end is 23 ° or less. Provided.

Further, in the indoor unit of the air conditioner according to the present invention, the blade outlet angle of the blade is set to 18 ° or more.

Further, in the indoor unit of the air conditioner according to the present invention, an inner / outer diameter ratio, an inner / outer diameter mounting ratio which is a ratio of an inner peripheral side mounting end diameter and an outer peripheral side mounting end diameter of the blade blade to the center of the impeller. End diameter / outer peripheral side mounting end diameter is set to 0.75 to 0.85.

Further, in the indoor unit of the air conditioner according to the present invention, the ratio of the maximum thickness in the cross section of the blade blade to the thickness of the portion excluding the round shape at the outer peripheral side mounting end, maximum thickness / outer peripheral side The thickness of the portion excluding the round shape at the mounting end is set to 1.3 to 1.5.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 and 2 are diagrams showing an example of an embodiment of the present invention. FIG. 1 is a graph of a noise value in an indoor unit of an air conditioner, and FIG. 2 is a graph of an air volume ratio at the same noise. In addition, the indoor unit of the air conditioner is configured by arranging the same members as those in FIGS. That is, a once-through blower is provided in the box 1 of the indoor unit of the separation-type air conditioner installed indoors (not shown).

Further, an impeller 2 of a once-through blower is provided,
A circular support plate 3 which is arranged apart from each other along the rotation axis of the impeller 2 and is provided concentrically with the rotation axis; A large number of wing blades 4 mounted annularly at a distance from each other
And has a diameter D shown in FIG.

A rear casing 5 is provided on the rear side of the box 1 of the impeller 2, a front casing 6 is provided on the front side of the box 1 of the impeller 2, and is formed between the rear casing 5 and the front casing 6. A blow air path 7, upper and lower flaps 8 provided at an outlet of the blow air path 7, and a heat exchanger 9 disposed upstream of the once-through blower are provided.

In FIG. 8, reference symbol A denotes an outer peripheral side mounting end of the blade 4 in the cross section of the impeller 2 with respect to the support plate 3;
Is the inner peripheral side mounting end of the blade 4 with respect to the support plate 3 in the cross section of the impeller 2, O ₀ is the rotation center of the impeller 2, O ₁ is the center of the circular arc in the cross section of the blade 4, and t _max is the blade. Feather 4
, _Tmin is the thickness of the portion of the outer peripheral side mounting end of the blade 4 excluding the round shape.

O ₀ A is an outer peripheral end A of the blade 4
Is a _first straight line connecting the rotation center O _{0 of the} impeller 2, O ₁ A is a second straight line connecting the outer peripheral side mounting end A of the blade 4 and the center O ₁ of the cross-sectional arc of the blade 4, and n is the A first perpendicular line at the outer peripheral side mounting end A of the straight line O ₀ A, m is a second perpendicular line at the outer peripheral side mounting end A of the second straight line O ₁ A, and β ₂ is an angle between the first perpendicular line n and the second perpendicular line m. The blade exit angle, l, is the center line in the thickness direction of the cross section of the blade 4.

In the indoor unit of the air conditioner configured as described above, the impeller 2 is driven and rotated by an electric motor (not shown) to apply energy to the air to increase the air pressure. Then, the air is blown to the blow-out air passage 7 which is formed in a tapered shape having a constant angle by a straight line and whose outlet side is widened,
The pressurized air flow is guided, and the air direction is controlled by the upper and lower flaps 8 from the outlet to be blown into the room. Thereby, an air conditioning operation is performed.

By setting the blade outlet angle β ₂ to 18 ° or more, the air volume ratio at the time of the same noise can be increased as shown in FIG. In addition, by setting the blade outlet angle β ₂ to 22 ° or less, it is possible to reduce the singular sound in the low frequency band as shown in FIG. 1 and to reduce the noise value at the same air volume. The optimum by large volume blow performance is obtained in, and in order to obtain an indoor unit of a specific sound generation is less air conditioner low frequencies, in the range of the blade outlet angle β ₂ 18 ° ~20 ° State can be realized.

Embodiment 2 FIG. FIG. 3 is a diagram showing an example of another embodiment of the present invention, and is a graph of an air volume ratio at the same noise in an indoor unit of an air conditioner. In addition, the indoor unit of the air conditioner is configured by arranging the same members as those in FIGS. In the indoor unit of the air conditioner according to Embodiment 1 described above, the inner peripheral side mounting end B diameter O ₀ B and the outer peripheral side mounting end A diameter O ₀ of the blade blade 4 with respect to the center O ₀ of the impeller 2.
The ratio of A, that is, the inner / outer diameter ratio (O ₀ B) / (O ₀ A) is set to 0.75 to 0.85.

Thus, as shown in FIG. 3, the air volume at the same noise can be increased. Therefore, it is possible to obtain an indoor unit of an air conditioner that can achieve a large air volume blowing performance and generate less low frequency peculiar sounds.

Embodiment 3 FIG. FIG. 4 also shows an example of another embodiment of the present invention, and is a graph of the noise ratio due to the blade blade at the same blade exit angle β ₂ in the low frequency band singular sound of the indoor unit of the air conditioner. . In addition, the indoor unit of the air conditioner is configured by arranging the same members as those in FIGS. In the indoor unit of the air conditioner according to Embodiments 1 and 2 described above, the maximum thickness t _max of the blade blade 4 is set.
And the ratio of the thickness t _min of the portion excluding the rounded shape on the outer peripheral side mounting end of the rotor blade _{4, t max / t min =} 1.3~
Set to 1.5.

As a result, the dynamic pressure generated by the impeller 2 is sufficiently recovered from the static pressure, so that the cross-sectional shape of the conventional blade 4, that is, the maximum thickness t _max and the roundness at the outer end of the blade 4 on the outer peripheral side. The thickness t _{min of the} part excluding the shape
The noise ratio is smaller than that of the wing blade 4 having the same value, and an increase in air volume can be achieved. In addition, it is possible to reduce the occurrence of singular sounds in a low frequency band.

Then, as shown in FIG. 4, t _max / t _min
When the ratio is 1.3 to 1.5, the noise ratio is smaller than that of the indoor unit of the conventional air conditioner, and the air volume can be increased. Therefore, it is possible to obtain an air conditioner indoor unit that has a large air volume blowing performance and low generation of low frequency peculiar sounds.

[0027]

As described above, according to the present invention, an impeller which is arranged in a box body and constitutes a once-through blower, a main part of the impeller is formed, and the plate faces face each other along the rotation axis of the impeller. And a circular support plate which is arranged apart from each other and is provided concentrically with the rotation axis, and another main portion of the impeller, which is formed in an arc shape in cross section and arranged between the support plates, and an outer edge of the support plate. A large number of them are mounted annularly apart from each other with the arc surfaces facing each other, and the first perpendicular line at the outer peripheral mounting end of the first straight line connecting the outer peripheral mounting end in the cross section of the impeller and the rotation center of the impeller, and A vane blade is provided which has a blade exit angle formed by a second perpendicular at the outer mounting end of a second straight line connecting the center of the circular arc of the cross section and the outer mounting end to 23 ° or less.

This makes it possible to reduce the peculiar sound in the low frequency band, and to obtain a large airflow performance by increasing the diameter of the impeller, and to operate quietly with less peculiar sound in the low frequency band. This has the effect of realizing an indoor unit of an air conditioner.

Further, as described above, the present invention is such that the blade exit angle of the blade is 18 ° or more.

As a result, the air volume ratio at the same noise level can be increased, and there is an effect of realizing an indoor unit of an air conditioner in which the required blowing performance can be easily obtained with low operation noise.

Further, as described above, the present invention provides an inner / outer diameter ratio, an inner / outer diameter ratio, which is a ratio of an inner peripheral side mounting end diameter and an outer peripheral side mounting end diameter of the blade to the center of the impeller. The side mounting end diameter is set to 0.75 to 0.85.

Thus, the air volume at the same noise can be increased, and there is an effect of realizing an indoor unit of an air conditioner in which the operation noise is small and the required blowing performance can be easily obtained.

Further, as described above, the present invention provides a ratio of the maximum thickness in the cross section of the blade blade to the thickness of a portion excluding the rounded shape at the outer peripheral mounting end in the cross section of the blade blade, The thickness of the portion excluding the round shape at the outer peripheral side mounting end is set to 1.3 to 1.5.

As a result, there is an effect that an indoor unit of an air conditioner can be realized in which the noise ratio is reduced and the air volume can be increased, the operating noise is reduced, and the required blowing performance can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention, and is a graph of a noise value in an indoor unit of an air conditioner.

FIG. 2 is a graph of an air volume ratio at the same noise in the air conditioner indoor unit corresponding to FIG.

FIG. 3 is a diagram showing the second embodiment of the present invention, and is a graph of the air volume ratio at the same noise in the indoor unit of the air conditioner.

FIG. 4 is a diagram illustrating a third embodiment of the present invention, and is a graph of a noise ratio due to blade blades at the same blade outlet angle β ₂ in a low frequency band singular sound of an indoor unit of an air conditioner.

FIG. 5 is a cross-sectional side view showing an indoor unit of a conventional air conditioner.

FIG. 6 is a front view of an impeller in the indoor unit of the air conditioner in FIG. 5;

FIG. 7 is a right side view of FIG. 6;

FIG. 8 is an enlarged view of a wing blade in FIG. 7;

[Explanation of symbols]

1 box body, 2 impellers, 3 support plates, 4 blades, A
Outer peripheral side mounting end, B Inner peripheral side mounting end, O ₀ impeller rotation center, O ₀ A first straight line, n first perpendicular, center of cross section circular arc of O ₁ blade, O ₁ A second straight line, m Second perpendicular,
β ₂ blade exit angle, t _{max maximum} blade blade thickness, t _min
The thickness of the part excluding the rounded shape at the outer peripheral side mounting end of the blade.

Claims (4)

[Claims] 1. An impeller which is arranged in a box body and constitutes a once-through blower, and which constitutes a main part of the impeller and which is arranged apart from each other with their plate faces facing each other along the rotation axis of the impeller. A circular support plate provided concentrically with the axis and another main part of the impeller are formed in an arc shape in cross section and arranged between the support plates, and a number of them are arranged near the outer edge of the support plate. Are mounted in a ring apart from each other with the arc faces facing each other,
A first straight line connecting the outer peripheral mounting end in the cross section of the impeller and the center of rotation of the impeller, a first perpendicular line at the outer peripheral mounting end and a center connecting the arc of the cross section and the outer peripheral mounting end. An indoor unit for an air conditioner, comprising: a blade exit angle formed by a second perpendicular at the outer peripheral mounting end of the two straight lines and having a blade exit angle of 23 ° or less. 2. The indoor unit of an air conditioner according to claim 1, wherein the blade outlet angle of the blade is set to 18 ° or more. 3. An inner / outer diameter ratio which is a ratio of an inner peripheral side mounting end diameter to an outer peripheral side mounting end diameter of the blade blade with respect to a center of the impeller, and an inner peripheral side mounting end diameter / outer peripheral side mounting end diameter is 0.75 to 0.75. The indoor unit of the air conditioner according to claim 1, wherein the indoor unit is set to 0.85. 4. The ratio of the maximum thickness in the cross section of the blade blade to the thickness of the outer peripheral mounting end excluding the rounded shape, and the maximum thickness / thickness of the outer peripheral mounting end excluding the rounded shape. The indoor unit of an air conditioner according to any one of claims 1 to 3, wherein the indoor unit is set to 1.3 to 1.5.