JP5008386B2 - Centrifugal multiblade blower - Google Patents

Description

  The present invention relates to a centrifugal multiblade fan.

Centrifugal multiblade fans used in air blowers such as air conditioners for vehicles have a cylindrical fan that is lined up on the outer periphery and driven to rotate in the circumferential direction by a motor, and stores the fan in a radial pattern. And a scroll-shaped scroll casing that rectifies the air flow discharged to the air and blows it out in one direction.
The centrifugal multiblade blower is desired to be miniaturized due to space limitations when mounted on a vehicle, for example.

In order to reduce the width of the scroll casing in the radial direction, it is effective to reduce the scroll opening angle, but this reduces the cross-sectional area of the flow path, so that the air flow rate decreases and the flow loss due to turbulence increases. There arises a problem that the efficiency of the blower deteriorates, such as generation of noise.
Therefore, a configuration is disclosed in which the cross-sectional area of the spiral flow path of the scroll casing is gradually enlarged from the upstream side to the downstream side (see Patent Document 1).
JP 2003-193998 A

However, a configuration in which the flow passage cross-sectional area is gradually expanded as in the technique disclosed in Patent Document 1 cannot obtain a sufficient air volume, and the efficiency in a practical area where a high air volume is required deteriorates. There is a problem of doing.
In addition, for example, a configuration in which the spiral flow path is expanded on both sides in the axial direction to expand the cross-sectional area of the flow path can be considered. This causes a problem that the inflow resistance of intake air increases and the efficiency of the fan decreases.

  The present invention has been made to solve such a problem. The object of the present invention is to ensure a sufficient flow cross-sectional area while reducing the size and to perform smooth intake, and to improve the efficiency of the fan. It is providing the centrifugal multiblade fan which can improve.

In order to achieve the above object, in the centrifugal multi-blade fan of claim 1, a fan having a cylindrical shape, a plurality of blades arranged in an outer peripheral portion, and having one axial end opened, and the fan A motor that rotationally drives to one side in the circumferential direction, a fan that houses the fan and the motor, and a side wall that has an intake port that corresponds to the opening of the fan, and is spaced apart from the one side wall in the axial direction of the fan The other side wall formed in this manner and the outer peripheral edge of the one side wall and the other side wall are connected, and the winding angle to one side in the circumferential direction increases with a predetermined radial direction as a reference position with respect to the axis of the fan. A scroll casing having a spiral wall formed in a spiral shape whose distance from the axis increases, and having a spiral flow path formed on the outer peripheral side of the fan by the one side wall, the other side wall, and the outer wall; One side wall is the intake air Expanded in a more outer peripheral side, the inclined plane inclined to the outer peripheral side with respect to the axial direction is formed, the outer peripheral side from the inclined surface is bulging in the axial direction one side, in the axial direction of the spiral flow path uniformly And the inclination angle of the inclined surface changes according to the winding angle of the scroll casing .

In 請 Motomeko 2 of the centrifugal multiblade blower, according to claim 1, wherein the inclined surface is characterized in that the minimum angle of inclination of the reference position of the scroll casing.
The centrifugal multiblade blower according to claim 3, wherein the inclined surface according to claim 1 or 2 is characterized in that the maximum inclination angle in the vicinity of the winding angle 180 ° position of the scroll casing.

The centrifugal multiblade blower according to claim 4 is characterized in that, in any one of claims 1 to 3 , a portion of the other side wall forming the spiral flow path bulges to the other side in the axial direction. .

  According to the centrifugal multi-blade fan of claim 1 of the present invention using the above means, on one side wall of the scroll casing forming the spiral flow path, the inclination is inclined to the outer peripheral side with respect to the axial direction from the intake port to the outer peripheral side. By forming a surface and bulging the outer peripheral side from the inclined surface to one side in the axial direction, it is possible to increase the cross-sectional area of the spiral flow path, thereby reducing the radial width of the scroll casing. Even if it is a case, a sufficient air volume can be ensured and a high air volume suitable for the practical range can be realized. In contrast, since the inclined surface is formed on the outer peripheral side, separation of the intake air flow can be suppressed by the inclined surface, and smooth intake with reduced inflow resistance can be performed. Further, by swelling one side wall of the spiral flow path, the vortex structure on one side of the spiral flow path can be suppressed and the flow loss can be reduced.

As described above, according to the centrifugal multiblade fan of claim 1 of the present invention, it is possible to ensure a sufficient flow passage cross-sectional area while reducing the size and to perform smooth intake, and to improve the efficiency of the fan. Can do.
According to the centrifugal multiblade fan of claims 1 to 3 , the inclined surface is changed in inclination angle according to the shape of the scroll casing and the flow of the intake air flow, and the flow passage cross-sectional area of the efficient spiral flow passage is secured. The inflow resistance can be reduced.

According to the centrifugal multiblade fan of claim 4 , the flow passage cross-sectional area of the spiral flow path can be further expanded by expanding the portion corresponding to the spiral flow path on the other side wall to the other side in the axial direction. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Referring to FIGS. 1 to 3, FIG. 1 is a perspective view of a centrifugal multiblade fan according to the present invention, and FIG. 2 is a plan view of the centrifugal multiblade fan according to the present invention as viewed from one axial side of a fan. 3 is a cross-sectional view taken along the line AA in FIG. Hereinafter, a description will be given based on FIG.
The blower 1 is used in a blower unit of a vehicle air conditioner, and is provided on the air flow downstream side of the inside / outside air introduction portion 2 in the ventilation duct (not shown) and the air flow upstream side of the evaporator 4.

The blower 1 mainly includes a fan 10, a motor 20, and a scroll casing 30.
The fan 10 has a cylindrical shape, and a plurality of blades 12 extending in the axial direction are arranged in an outer peripheral portion. The blade 12 has a shape extending from the inner peripheral side to the outer peripheral side while being curved from the inner peripheral side to the one circumferential side in plan view. Further, one end of the blade 12 is inclined toward the other side in the axial direction from the central portion toward the outer peripheral side.

Further, one end portion of each blade 12 is connected to a circumferential rim 14 extending in the circumferential direction.
On the other side in the axial direction of the fan 10, an outer peripheral edge portion is connected to an inner peripheral side portion at the other end of each blade 12, and a cone portion having a substantially conical shape bulging toward one side in the axial direction toward the center. 16 is formed. A boss hole 16a is formed in the central portion of the cone portion 16, and the rotating shaft 22 of the motor 20 is fitted in the boss hole 16a.

The motor 20 is provided so as to be housed inside the cone portion 16 of the fan 10, and has a function of rotating the fan 10 in the circumferential direction via the rotating shaft 22 when electric power is supplied.
The fan 10 is rotated to one side in the circumferential direction by the motor 20 to suck air from one side in the axial direction, that is, from the inner circumference of the rim 14, and the air sucked into the inner circumference side is radially emitted to the outer circumference side by the blade 12. Has a function of discharging. In this embodiment, the fan 10 has a clockwise direction as viewed in the plan view of FIG.

The scroll casing 30 houses the fan 10 and the motor 20 in the central portion in plan view.
The scroll casing 30 includes one side wall 32 and another side wall 34 that are spaced apart from each other in the axial direction of the fan 10, and the outer peripheral edges of the one side wall 32 and the other side wall 34 that are parallel to the axial direction of the fan 10. It is comprised from the outer peripheral wall 36 connected and extended.

The outer peripheral wall 36 includes a spiral part 36a, a flat part 36b, a tongue part 36c, and an extension part 36d.
The spiral portion 36a has an axis θ of the fan 10 as a central axis and a predetermined radial direction as a reference position (θ = 0 °), and an angle θ (hereinafter referred to as a winding angle θ) in the rotation direction of the fan 10 from the reference position. As the distance increases, the spiral shape is curved so that the distance from the central axis increases.

The spiral portion 36a extends from a reference position over a predetermined high angle position (for example, θ = 300 °), and after the high angle position, a flat portion 36b extending flat in the tangential direction is formed. Yes.
Further, at the reference position portion, a tongue portion 36c that is curved from the spiral portion 36a toward the outer peripheral side in the radial direction is formed, and the extension portion that extends from the tongue portion 36c toward the outer peripheral side in the radial direction so as to be separated from the flat portion 36b. 36d is formed.

A portion between the outer peripheral wall 36 and the outer periphery of the fan 10 is a spiral flow path 38, and the end of the spiral flow path 38 is the end portion of the flat portion 36 b and the extension portion 36 d of the outer peripheral wall 36 and one side wall 32. And the other side wall 34 has comprised the blower outlet 38a opened to the evaporator 4 side.
The other side wall 34 includes a central surface 34 a corresponding to the position of the fan 10, an outer peripheral surface 34 b corresponding to the spiral flow path 38 portion, and a vertical surface 34 c.

  The central surface 34a and the outer peripheral surface 34b of the other side wall 34 are perpendicular to the axial direction, the central surface 34a is positioned near the other end of the fan 10, and the outer peripheral surface 34b is more axial than the central surface 34a. Located in the other direction. A motor support hole 34d is formed in the central surface 34a, and the motor 20 is supported in the motor support hole 34d via the bracket 24. The vertical surface 34c is parallel to the axial direction and extends in the circumferential direction from the outer peripheral edge of the central surface 34a to the inner peripheral edge of the outer peripheral surface 34b.

The one side wall 32 includes an intake port edge portion 32b having an intake port 32a corresponding to the position of the fan 10, an outer peripheral surface 32c corresponding to the spiral flow path 38 portion, and an inclined surface 32d.
The intake port 32 a of the one side wall 32 forms a circular hole having substantially the same diameter as the inner periphery of the rim 14 of the fan 10. The air inlet edge 32b and the outer peripheral surface 32c are perpendicular to the axial direction, the air inlet edge 32b is positioned near one end of the fan 10, and the outer peripheral surface 32c is the air inlet edge 32b in plan view. It is located on the outer peripheral side, on one side of the intake port edge portion 32b in the axial direction.

The inclined surface 32d is a surface extending in the circumferential direction over the inner peripheral edge of the outer peripheral surface 32c with an inclination angle r from the outer peripheral edge of the intake port edge portion 32b to the outer peripheral side with respect to the axial direction.
The inclination angle r of the inclined surface 32d changes according to the winding angle θ, and is specifically expressed by the following equation.
r = 45 deg × sin (θ / 2)
That is, at the reference position where the winding angle θ = 0 °, the tilt angle is 0 °, that is, a plane parallel to the axis. As the winding angle θ increases from the reference position, the inclination angle r increases, and the maximum inclination angle is 45 ° at the winding angle of 180 °. Further, when the winding angle θ increases, the inclination angle r decreases, and the inclination angle becomes 0 ° again when the spiral angle is 360 °, that is, the spiral angle is 0 °.

  As described above, in the scroll casing 30, the one side wall 32 and the other side wall 34 swell in the axial direction in the spiral flow path 38 portion that is the outer peripheral portion of the portion where the fan 10 is provided. The path 38 is configured to expand in the axial direction. In particular, the one side wall 32 having the air inlet 32a bulges through an inclined surface 32d whose inclination angle r changes according to the winding angle θ.

Hereinafter, the operation of the centrifugal multiblade fan configured as described above will be described.
In the centrifugal multiblade fan, when the electric power is supplied to the motor 20, the fan 10 rotates through the rotating shaft 22. By the rotation of the fan 10, air is sucked from the air inlet 32 a to the inner peripheral side of the fan 10 through the inner periphery of the rim 14. Then, the air on the inner peripheral side of the fan 10 is radially discharged to the outer peripheral side through the blade 12, and the air is rectified to the outlet 38 a by the spiral flow path 38 of the scroll casing 30 and blown to the evaporator 4 side. The

  Specifically, the air flow sucked into the inner peripheral side of the fan 10 and discharged to the outer peripheral side by the blade 12 is the other side in the axial direction along the shape of the substantially conical cone portion 16 from the intake port 32a and the outer peripheral side in plan view. Is discharged. Then, the air flow collides with the outer peripheral wall 36 in the spiral flow path 38, and is deflected mainly to one side in the axial direction to form a secondary flow that flows to the bulging portion of the one side wall 32, and to the air outlet 38 a. Head to.

In the centrifugal multiblade fan configured as described above, since the spiral flow path 38 is uniformly expanded in the axial direction, even if the radial width of the scroll casing 30 is reduced, a sufficient flow rate is achieved. A road cross-sectional area can be secured and a high air volume can be realized.
Further, by swelling the one side wall 32 and the other side wall 34 of the spiral flow path 38, the vortex structure on one side and the other side of the spiral flow path 38 can be suppressed, and the flow loss can be reduced.

Further, since the bulging portion of the one side wall 32 on the intake port 32a side bulges through an inclined surface 32d inclined to the outer peripheral side with respect to the axial direction, the inclined surface 32d suppresses separation of the intake air flow. Therefore, smooth intake with reduced inflow resistance can be performed.
Thus, since the intake air can be made smooth while enlarging the channel cross-sectional area of the spiral channel 38, the performance of the centrifugal multiblade fan can be improved efficiently.

  Further, the inclined surface 32d minimizes the inclination angle r in the vicinity of the reference position where the channel cross-sectional area is narrow, thereby avoiding the reduction of the channel cross-sectional area, and sufficient channel disconnection such as the position near the winding angle of 180 °. In the portion where the area can be ensured, by increasing the inclination angle r and reducing the inflow resistance of the intake air, it is possible to efficiently secure the cross-sectional area of the spiral flow path and reduce the inflow resistance.

From the above, in the centrifugal multiblade fan according to the present application, the efficiency of the fan 10 can be improved as it is possible to ensure a sufficient flow path cross-sectional area while being reduced in size and to perform smooth intake.
Although the description about embodiment of the centrifugal multiblade fan which concerns on this invention is finished above, embodiment is not restricted to the said embodiment.

The expression of the inclination angle r is not limited to that in the above embodiment, and for example, the constant portion 45 deg in the above embodiment may be set to another value. Or, in the range of θ from 0 ° to 180 °,
r = constant × sin (θ / 2)
In the range of θ from 180 ° to 270 °,
r = constant × sin (θ−90)
And r = 0 in the range of θ from 270 ° to 360 °.

In the above embodiment, the inlet edge 32b perpendicular to the axis is formed on the one side wall 32. For example, the edge of the inlet may be used as the inner peripheral edge of the inclined surface so as to form an inclined surface directly from the inlet. I do not care.
Moreover, in the said embodiment, although the outer peripheral surface of the other side wall 34 has comprised the structure which bulged to the other side, about the shape of the said other side wall, it is not restricted to this, For example, you may make it a whole surface flat surface. .

1 is a perspective view of a centrifugal multiblade fan according to the present invention. It is the top view seen from the axial direction one side of the fan of the centrifugal multiblade fan concerning the present invention. It is sectional drawing which follows the AA line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blower 10 Fan 20 Motor 30 Scroll casing 32 One side wall 32a Inlet port 32b Inlet port edge part 32c Outer peripheral surface 32d Inclined surface 34 Other side wall 36 Outer peripheral wall 38 Spiral flow path

Claims (4)

A fan having a cylindrical shape, a plurality of blades arranged in an outer peripheral portion, and having one axial end opened,
A motor that rotationally drives the fan to one side in the circumferential direction;
One side wall that houses the fan and the motor and has an intake port formed corresponding to the opening of the fan, another side wall that is spaced apart from the one side wall in the axial direction of the fan, and the one side The outer peripheral edge of the side wall and the other side wall is connected to form a spiral shape in which the distance from the axial line increases as the winding angle to one side in the circumferential direction increases with a predetermined radial direction as a reference position with respect to the axial line of the fan. A scroll casing having a spiral flow path formed on the outer peripheral side of the fan by the outer peripheral wall formed by the one side wall, the other side wall, and the outer peripheral wall;
The one side wall, the outer peripheral side of the air inlet, the inclined surface inclined on the outer peripheral side with respect to the axis direction is formed, the outer peripheral side from the inclined surface is bulging in the axial direction one side, the spiral flow path Is expanded uniformly in the axial direction,
The centrifugal multiblade fan , wherein the inclined surface has an inclination angle changed according to a winding angle of the scroll casing . The inclined surface is centrifugal multiblade blower according to claim 1, characterized in that the minimum angle of inclination of the reference position of the scroll casing. The centrifugal multiblade fan according to claim 1 or 2 , wherein the inclined surface has a maximum inclination angle in the vicinity of a winding angle of 180 ° of the scroll casing. The centrifugal multiblade fan according to any one of claims 1 to 3 , wherein a portion of the other side wall that forms the spiral flow path bulges to the other side in the axial direction.

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