JP3482231B2 - Air volume adjustment device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow rate adjusting device for a centrifugal blower used in ventilation blowers and air conditioners.

[0002]

2. Description of the Related Art Heretofore, this type of air volume adjusting device generally has a scroll-shaped damper which has one end in contact with an inner wall surface of a scroll of a casing as an axis and the other end as a vicinity of a discharge port of the casing for rotational movement. Met.

The structure will be described below with reference to FIGS. 24 to 27. Shaft 1 as shown
Impeller 102 and casing side 10 connected to 01
3 and the casing 105 composed of the scroll 104
In a double-suction type centrifugal blower having a scroll 1,
A scroll-shaped damper 108 having an end portion 106 in contact with the inner wall surface of 04 and an end portion 107 located near the discharge port and a drive portion 109 are arranged.

In the above structure, a driving force is applied to the shaft 101 to rotate the impeller 102, so that air is sucked from the suction port 110 and the impeller 10 is rotated.
The pressure is increased by 2, passes through the casing 105, and is discharged from the discharge port 111. At this time, the end portion 106
The damper 108 and the end portion 107 thereof with the shaft as an axis
By rotationally moving by using the drive unit 109, the scroll enlargement angle is reduced, the ventilation opening area near the discharge port is reduced, the air volume is adjusted, and a predetermined air volume is obtained.

[0005]

In such a conventional air flow rate adjusting device, most of the air sucked from the suction port 110 is the blade 112 of the impeller 102 in the air flow rate reduction adjustment especially from the low static pressure use state. It flows out into the casing 105 through the main plate 113 side of the. At this time, although most of the high-velocity air flows out in the vicinity of the center line of the scroll 104, the damper 108 is adjusted and moved in the direction in which the scroll expansion angle decreases and in parallel to the axial direction. Therefore, in the vicinity of the center line and the end portion 107 of the damper 108, there is a problem that the turbulent noise due to the flow collision and the separation phenomenon increases in the range of about 70% to 100% of the air flow rate.

Further, there is a problem that noise is generated in a low frequency range due to the vibration of the damper 108 using air vibration as a vibration source in the range of the air volume ratio of about 50% or less.

Further, the shaft power at the time of adjusting the air volume is the damper 1 described above.
There is a problem that the energy saving effect is not so great because 08 almost changes along the axial power curve corresponding to the static pressure-air volume curve in the fully opened state along the inner wall of the scroll 104.

SUMMARY OF THE INVENTION The first object of the present invention is to solve the above problems and to reduce turbulent noise due to flow collision and separation phenomena.

A second object is to obtain an energy saving effect by lowering the shaft power when adjusting the air volume below the initial shaft power curve when the damper is fully opened or the device is not installed.

A third object is to reduce noise due to the vibration of the air flow rate adjusting device itself, which uses aerial vibration as a vibration source.

[0011]

In the air flow rate adjusting device of the present invention, the first means for achieving the first and second objects is to provide a discharge port and a discharge duct of a casing of a double suction type centrifugal blower. Two rectangular adjustment plates that rotate around an end contacting one side as an axis are installed on both inner wall surfaces on the casing side in the region closer to the casing than the connecting portion.

Further, the second means for achieving the first and second objects is such that the end portion which is in contact with the upper inner wall surface in the vicinity of the discharge port of the scroll of the casing has a short side and is in contact with the lower inner wall surface. A trapezoidal adjustment plate whose end portion has a longer side longer than the short side is installed.

Further, the third means for achieving the first and second objects is configured to adjust the air volume by changing the rotation angles of the two adjusting plates to different rotation angles.

A fourth means for achieving the first and second objects is to install an adjusting plate which is curved with a curvature perpendicular to one side in contact with the inner wall surface of the casing side. It will be configured.

The fifth means for achieving the first and second objects has a curvature bent toward the discharge direction at the end of the adjusting plate forming the ventilation opening through which the discharge air passes. An arc-shaped bent portion is arranged.

Further, a sixth means for achieving the first and second objects is constituted by arranging an auxiliary rectifying plate installed on the casing side surface of the adjusting plate.

Further, a seventh means for achieving the first, second and third objects is a structure in which a bent portion is provided at an upper edge portion and a lower edge portion of the adjusting plate or ribs are arranged on a surface of the adjusting plate. And

Further, the eighth means for achieving the first, second and third objects has a construction in which the adjusting plate is installed by a sound absorbing member.

[0019]

According to the present invention, with the construction of the above-mentioned first means, the adjusting plate is rotated without blocking the air having a high flow velocity flowing near the center line of the scroll and flowing out from the vicinity of the center line in the vertical direction of the discharge port as much as possible. Turbulence noise can be reduced by moving and adjusting the air flow rate, and loss can be reduced and shaft power can be reduced by the backflow prevention effect.

Further, according to the constitution of the second means, particularly in the adjustment of the air volume ratio in the range of 70% to 100%, the adjusting plate is provided without blocking the fast flowing air which is biased toward the upper part of the center line of the discharge port. The turbulent noise can be reduced by rotating and adjusting the air volume, and the backflow prevention effect can reduce loss and shaft power.

Further, according to the structure of the third means, the discharge port due to the imbalance of the amount of air sucked from each suction port generated when the housing part of the motor is installed near one of the suction ports on the casing side. With respect to the deviation of the flow in the left-right direction, the turbulence noise can be reduced by changing the rotation angle of each adjusting plate to adjust the air volume, and the backflow prevention effect can reduce the loss and the shaft power.

Further, according to the structure of the fourth means, the turbulent flow noise can be reduced and the backflow can be prevented because the air volume can be adjusted with the curved adjusting plate forming the ventilation opening, particularly the direction of the lower end thereof being close to the discharge direction. The action reduces loss and shaft power.

Further, by virtue of the structure of the fifth means, the turbulent noise is reduced by weakening the vortex of the collision and the wake of the outflowing air generated at the end of the adjusting plate forming the ventilation opening by the bent portion. It is possible to reduce the loss and the shaft power by the backflow prevention function.

Further, according to the structure of the sixth means, turbulent noise is generated when passing the lower side, which is a small area of the ventilation opening, as the air volume is reduced particularly in the adjustment of the air volume ratio in the range of 50% to 80%. The turbulent noise can be reduced by rectifying and flowing the turbulent flow of the outflowing air to the upper side, which is a large area, and at the same time, the backflow prevention effect can reduce loss and shaft power.

Further, according to the structure of the seventh means, the noise of resonance can be reduced by improving the strength of the adjusting plate which causes the resonance phenomenon due to pneumatic (fluidic) vibration without impairing the accuracy of the air volume adjustment. At the same time, the turbulent noise and backflow preventive action can reduce loss and reduce shaft power.

With the structure of the eighth means, the turbulent flow noise and the noise due to resonance generated when passing through the adjusting plate can be absorbed and reduced, and the backflow preventing effect can reduce the loss and the shaft power.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG. The same parts as those in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown, the discharge end 1 of the casing
2 is a rectangular adjustment plate 5a having an end 4 that rotates around an end 3 that is in contact with the inner wall surface of the casing side 103 on the casing side of the connecting portion between the discharge duct 2 and the discharge duct 2.
It has a structure in which one sheet is arranged.

With the above construction, the adjusting angle θ of the adjusting plate 5a is in the range of 0 ° to 90 ° and the air volume is 0% to 100%.
At this time, most of the high-velocity air sucked from the suction port 110 passes through the blade 112 on the side of the main plate 113 of the impeller 102 to scroll when the air volume is adjusted especially from a low static pressure state. Although it flows out toward the discharge port 111 in the vicinity of the center line 6 of 104, the ventilation opening A formed by the end 4 of the adjusting plate 5a does not become an obstacle to directly disturb the mainstream discharge flow. By changing (adjusting) while leaving the central part in the duct, turbulent noise due to flow collision and separation phenomena can be reduced.

Further, in the vicinity of the discharge port 111, which is concerned when the air volume is reduced by simply applying pressure without installing the air volume adjusting device or when the air volume is reduced by the adjustment of the scroll-shaped damper. In particular, the secondary backflow phenomenon to the suction port 110 along the inner wall surface 103s of the duct side and the inner wall surface of the casing side 103 is blocked by the adjusting plate 5a, so that backflow loss can be prevented, and the shaft power is reduced to the initial shaft. It can be reduced by 5% to 8% from the power curve.

The length 1 of the adjusting plate 5a is preferably set within the range of 60% to 70% of the axial length L of the discharge port 111. Further, since the end portion 3 is installed closer to the casing than the connecting portion between the discharge end portion 1 and the discharge duct 2 of the casing, the end portion 3 can be easily attached, and the damper system having a scroll shape can be commercialized and adjusted. The required short pipe is unnecessary, so the installation area and construction cost can be reduced, and maintainability will be improved.

In the single-suction type centrifugal blower, 1
It goes without saying that the end portions 3 of the one adjusting plate 5a may be installed so as to be rotationally moved to the inner wall surface of the casing side 103 on the suction port side, and there is no difference in the action and effect.

As described above, according to the air flow rate adjusting device of the first embodiment of the present invention, turbulent noise is generated due to the turbulence of the mainstream discharge flow of the air having a high flow velocity, which is discharged near the center line of the scroll. Therefore, it is possible to prevent noise, reduce backflow phenomenon that may occur when the air volume decreases, and reduce shaft power.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the drawing, a trapezoidal adjusting plate 5b composed of an end portion 3 serving as an axis of rotational movement, an end portion 4 which rotationally moves to form a ventilation opening A, and short sides 7 and long sides 8 is formed. It has a configuration in which two sheets are arranged.

With the above construction, the adjusting angle θ of the adjusting plate 5 is in the range of 0 ° to 90 ° and the air volume is about 40% to 100%.
Can be adjusted up to. At this time, especially the air volume ratio is 70
The main flow of the intake air in the adjustment range of 100% to 100% flows out in a biased manner to the upper part of the center line 9 of the discharge port 111, but since the area of the ventilation opening A is large in the upper part, the main flow having a high flow velocity. Since the adjusting plate 5b can be rotationally moved in a state where it does not directly disturb the discharge flow, turbulent noise due to collision and separation phenomena can be reduced.

The adjusting plate 5b is the same as in the first embodiment.
As a result, the secondary backflow phenomenon is blocked, so backflow loss can be prevented and shaft power can be reduced.

The length l ₁ of the long side 8 is 60% to 70% of the axial length L of the discharge port 111, and the short side 7
It is desirable that the length l ₂ of the above is set within the range of 30% to 35% of the length L.

As described above, according to the air flow rate adjusting device of the second embodiment of the present invention, the turbulent noise caused by the turbulence of the mainstream discharge flow is generated by adjusting the rotational movement by increasing the area above the ventilation opening. Example 1 in the same air flow adjustment range that can be prevented
It is possible to reduce the noise as described above and prevent a backflow phenomenon which may occur when the air volume is reduced, so that the shaft power can be reduced.

Next, a third embodiment of the present invention will be described with reference to FIGS. 9 and 10. The same parts as those in the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, the casing side 103
The motor 114 is installed in the vicinity of the suction port 110a on the a side, and the adjustment angles θ ₁ and θ _{2 of the} trapezoidal adjustment plates 5b ₁ and 5b ₂ can be adjusted independently.

With the above structure, since the motor 114 is installed in the vicinity of the suction port 110a, the amount of air sucked in is smaller than that of the suction port 110b, so that imbalance occurs and the inside of the casing 105 passes through the impeller 102. The air flow passing through the outlet flows toward the discharge port 111 in a state of being biased toward the casing side 103b side, but the ventilation openings A are positioned on the casing side 103b side so that the adjustment angles θ ₁ and θ ₂ are located on the casing side 103b side. Since the angle can be adjusted while being set to various angles, there is no direct obstacle to the mainstream discharge flow having a high flow velocity, and turbulent noise due to collision and separation phenomena can be reduced.

Further, the adjusting plate 5b is the same as in the first embodiment.
_{Since the} secondary backflow phenomenon is blocked by ₁ and 5b _2, backflow loss can be prevented and the shaft power can be reduced.

As described above, according to the air flow rate adjusting device of the third embodiment of the present invention, by adjusting the respective adjustment angles to different angles with respect to the flow deviation caused by the imbalance of the intake air flow rate, the mainstream discharge flow It is possible to prevent generation of turbulent flow noise due to turbulence, to achieve low noise, and to prevent a backflow phenomenon which is a concern when the air volume decreases, and to reduce shaft power.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
~ It demonstrates, referring to FIG. The same parts as those in the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, the casing side 103
2 is provided with two adjusting plates 5c which are curved in a direction perpendicular to the end portion 3 in contact with the inner wall surface and curved in the discharge direction.

[0047] With this configuration, when the curvature was as one arc, in particular an end portion 4 _L lower than the warp S becomes large in the lower part of the adjustment plate 5c, closer to the discharge direction. Therefore, in adjusting the air volume ratio of about 40% to 70%, the mainstream discharge flow passes through the lower portion of the discharge port 111 as the rotation speed increases, while the mainstream discharge flow passes through the lower portion of the end portion 4 more smoothly. As a result, the turbulent noise due to the collision and the vortex in the wake can be reduced.

The adjusting plate 5c is also the same as in the first embodiment.
As a result, the secondary backflow phenomenon is blocked, so backflow loss can be prevented and shaft power can be reduced.

The sled S has a maximum chord length l of the long side 8.
It is preferably 12% or less of _L. If it is within this range, the air volume at full opening is 100% without this adjusting device.
It has been confirmed by an experiment that a decrease of 0.5% to 1% may be sufficient.

As described above, according to the fourth embodiment of the present invention,
By adjusting the rotationally moving end of the adjusting plate close to the flow discharge direction, it is possible to prevent the generation of turbulent noise, and it is possible to reduce the noise more than in the second embodiment and to worry about the backflow phenomenon when the air volume decreases. Can be prevented and the shaft power can be reduced.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
~ It demonstrates with reference to FIG. The same parts as those in the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, a bending portion 10 having a curvature is additionally provided at the end 4 of the adjusting plate 5b.

With the above structure, since the bent portion 10 of the end portion 4 forming the ventilation opening A is bent to the downstream side of the outflow air, the air passing near the end portion 4 in the entire air volume adjustment range. Since the flow energy of the flow is reduced by the bending portion 10 and flows out smoothly, it is possible to reduce the generation of wake vortices and the turbulent noise due to the vortices.

The adjusting plate 5b is also the same as in the first embodiment.
As a result, the secondary backflow phenomenon is blocked, so backflow loss can be prevented and shaft power can be reduced.

When setting the curvature dimension of the bent portion 10, the height H with respect to the chord length l _U connecting the upper end of the end portion 3 and the upper end of the bent end portion 11 is 12% or less of the chord length l _U. It is desirable to set the curvature dimension as follows.

Thus, according to the fifth embodiment of the present invention,
By disposing the bent portion, it is possible to prevent the generation of turbulent noise by reducing the collision energy of the flow when passing near the bent portion, and it is possible to reduce the noise more than in the second embodiment and at the time of reducing the air volume. It is possible to prevent a feared backflow phenomenon and reduce shaft power.

A sixth embodiment of the present invention will now be described with reference to FIG.
~ It demonstrates, referring FIG. The same parts as those in the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, a flat auxiliary rectifying plate 12 is arranged on the casing 105 side of the adjusting plate 5b.

In the above structure, as the air volume is decreased by adjusting the air volume, the rotational speed of the impeller 102 increases, so that the circumferential component V of the outflow air velocity near the outer diameter of the impeller increases and the mainstream flow is discharged from the discharge port 111. The flow toward the lower portion having a small area of the ventilation opening A is large because the auxiliary rectifying plate 12 is arranged at this time. The flow is adjusted in the diverted and rectified state. Therefore, the turbulent noise generated by the collision and the vortex in the wake can be reduced. The auxiliary rectifying plate 12 is replaced with a flat plate and a curved plate 13 having a curvature.
If this is set, noise can be further reduced.

The adjusting plate 5b is also the same as in the first embodiment.
As a result, the secondary backflow phenomenon is blocked, so backflow loss can be prevented and shaft power can be reduced.

Thus, according to the sixth embodiment of the present invention,
As the flow rate decreases by adjustment, the mainstream discharge flow, which has a high flow velocity, has a small area of the ventilation opening. It is biased downward and rectified by an auxiliary rectifying plate to flow out above the ventilation opening. It is possible to prevent the generation of turbulent flow noise during passage, achieve the noise reduction of the second embodiment or higher, and prevent the backflow phenomenon that is a concern when the air volume decreases, and reduce the shaft power.

Next, the seventh embodiment of the present invention will be described with reference to FIG.
22 and FIG. 22. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, the adjusting plate 5b has a bent portion 16 on the upper side 14 and the lower side 15.

With the above structure, the low-frequency vibration in the direction of arrow B due to the resonance of the adjusting plate 5b with the vibration source as the vibration source, which is a concern in the adjustment especially in the range of the air volume ratio of about 50% or less, is caused by the bending portion 16. As a result, the strength of the adjusting plate 5b is improved, so that vibration and noise caused by this vibration can be prevented.

Even if the rib 17 is formed on the surface of the adjusting plate 5b instead of the bent portion 16, there is no difference in the function and effect.

As described above, according to the seventh embodiment of the present invention,
In addition to the function and effect of the second embodiment, it is possible to prevent vibration and vibration noise of the adjusting plate due to resonance by providing bent portions or ribs on the adjusting plate to improve the strength.

FIG. 23 shows the eighth embodiment of the present invention.
Will be described with reference to. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, the adjusting plate 5d formed of the sound absorbing member C is installed.

With the above construction, in addition to the operational effects of the seventh embodiment, the turbulent noise due to the collision and separation phenomenon generated by the flow passing near the adjusting plate 5d can be absorbed and reduced by the adjusting plate 5d.

Thus, according to the eighth embodiment of the present invention,
Turbulent noise can be reduced by the adjusting plate formed of the sound absorbing member, and the noise reduction of the seventh or more embodiment can be achieved.

[0071]

As is apparent from the above embodiments, according to the present invention, it is possible to provide an air volume adjusting device which is effective in reducing noise and vibration generated during air volume adjustment and shaft power during air volume adjustment.

[Brief description of drawings]

FIG. 1 is a perspective view of an air volume adjusting device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the same.

FIG. 3 is a vertical sectional view of the same.

[Figure 4] Same characteristic diagram

FIG. 5 is a perspective view of the second embodiment.

FIG. 6 is a transverse sectional view of the same.

FIG. 7 is a vertical sectional view of the same.

[Figure 8] Same characteristic diagram

FIG. 9 is a perspective view of the third embodiment.

FIG. 10 is a transverse sectional view of the same.

FIG. 11 is a perspective view of the fourth embodiment.

FIG. 12 is a transverse sectional view of the same.

FIG. 13 is a characteristic diagram of the same.

FIG. 14 is a perspective view of the fifth embodiment.

FIG. 15 is a transverse sectional view of the same.

FIG. 16 is a characteristic diagram of the same.

FIG. 17 is a perspective view of the sixth embodiment.

FIG. 18 is a transverse sectional view of the same.

FIG. 19 is a vertical sectional view of the same.

FIG. 20 is a characteristic diagram of the same.

FIG. 21 is a cross sectional view of the seventh embodiment.

22A is an enlarged view of the adjustment plate, FIG. 22B is an enlarged front view of a bent portion of the adjustment plate, and FIG. 22C is a DD enlarged cross-sectional view of the folded portion of the adjustment plate. Enlarged view of the adjusting plate in the case (e) Enlarged front view of the rib of the adjusting plate in the case of forming the same rib (f) EE of the rib of the adjusting plate in the case of forming the same rib
Enlarged sectional view

FIG. 23 (a) is an enlarged front view of an essential part of the eighth embodiment. (B) An enlarged top view of the essential parts of the eighth embodiment

FIG. 24 is a perspective view of a conventional air volume adjusting device.

FIG. 25 is a vertical sectional view of the same.

FIG. 26 is a transverse sectional view of the same.

FIG. 27 is a characteristic diagram of the same.

[Explanation of symbols]

1 Discharge End 2 Discharge Duct 3 End 5a Adjustment Plate 5b Adjustment Plate 5b ₁ Adjustment Plate 5b ₂ Adjustment Plate 5c Adjustment Plate 5d Adjustment Plate 7 Short Side 8 Long Side 10 Bent 12 Auxiliary Rectifier 14 Upper Side 15 Lower Side 16 Bent 17 rib C sound absorbing member 103 casing side 111 discharge port

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-4-350400 (JP, A) JP-A-7-117457 (JP, A) JP-A-5-65895 (JP, A) Actual Kaihei 1- 61498 (JP, U) Actually open 52-130468 (JP, U) Actually open 63-10309 (JP, U) Actually open 62-6611 (JP, U) Actually open 63-9499 (JP, U) Actual Kaihei 5-36096 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F04D 29/44 F04D 17/04 F04D 27/00 101

Claims (9)

(57) [Claims] 1. Two pieces which rotate about an end whose one side is in contact with both inner wall surfaces of a casing side in a region closer to the casing than a connecting portion between a discharge end of a casing of a double suction type centrifugal blower and a discharge duct. install a regulating johnsongrass
An air volume adjustment device that adjusts the air volume. 2. A trapezoidal shape adjustment in which an end portion in contact with an upper inner wall surface near a discharge port of a scroll of a casing is the short side, and an end portion in contact with a lower inner wall surface is a long side longer than the short side. The air volume adjusting device according to claim 1, wherein a plate is installed. 3. The air flow rate adjusting device according to claim 1, wherein the air flow rate is adjusted by changing the rotation angles of the two adjusting plates to different rotation angles. 4. A single-suction type centrifugal blower casing discharge.
The casing side from the connecting portion of the outlet end and the discharge duct
On the inner wall surface of the casing side of the suction port side in the area
One adjustment plate that rotates around the end where the sides touch
An air volume adjusting device which is installed to adjust the air volume, the adjustment comprising:
The plate is located inside the casing near the discharge port of the scroll.
The edge that touches the wall is the short side, and the edge that touches the inner wall below
Airflow control with trapezoidal shape where the long side is longer than the short side
Straightening device . 5. The adjusting plate is provided on the casing side.
A curved shape in the discharge direction from the end contacting the inner wall surface.
The air volume adjusting device described in 2 or 4. 6. A discharge flow rate of the air arcuate bent portion formed by arranging the claims 2 or 4 wherein having a curvature formed by bending the discharge direction side end portion of the adjusting plate forming the ventilation openings passing Adjustment device. 7. Adjustment plate air volume regulating device of the casing side surface formed by arranging installed auxiliary straightening vane to claim 2, 3 or 4, wherein the. 8. The air flow rate adjusting device according to any one of claims 1 to 7 , wherein bent portions are provided on the upper side and the lower side of the adjusting plate or ribs are arranged on the surface of the adjusting plate. 9. air volume regulating device according to any one of claims 1-8 which is installed to constitute the adjusting plate with the sound absorbing member.