WO2014002392A1 - Centrifugal multi-blade blower - Google Patents

Abstract

A centrifugal multi-blade blower is provided with an impeller (7a) and a casing (7b) that encloses the impeller (7a). The centrifugal multi-blade blower blows, towards the radial outer side of a rotation shaft (70), air which is suctioned from an intake port (74) of the casing (7b) which opens at at least one end of the rotation shaft (70). The impeller (7a) has the following: a main plate (73) connected to the rotation shaft (70); a plurality of blades (71) disposed in the vicinity of the axis of the rotation shaft (70) and configured so that the other end of the rotation shaft (70) is linked to the main plate (73); and a lateral plate (72) that links the blades (71) at the one end of the rotation shaft (70). With respect to the blades (71), an entrance angle (α), on a cross-section intersecting a prescribed direction with respect to each inner circumference edge part (711) of the blades (71) on a meridian plane of the impeller (7a), is uniform in the entire region reaching from the lateral plate (72) to the main plate (73). Further, an outer circumference edge part (712) of the blades (71) is configured so as to be spaced apart from the axis of the rotation shaft (70) from the main plate (73) towards the lateral plate (72).

Description

Centrifugal multiblade blower Cross-reference of related applications

This disclosure is based on Japanese Application No. 2012-142803 filed on June 26, 2012 and Japanese Application No. 2013-100170 filed on May 10, 2013. Is used.

The present disclosure relates to a centrifugal multiblade blower that blows out air sucked from the direction of the rotation shaft toward the outside in the radial direction of the rotation shaft.

A conventional impeller of a centrifugal multiblade fan has a plurality of blades arranged around a rotating shaft, and blows out air sucked in from the rotating shaft direction outward in the radial direction. Yes.

In this impeller, the wind direction changes rapidly from the rotational axis direction to the radial direction in the space near the air suction port in the space between the adjacent blades (hereinafter, the space between the blades). The air hardly flows compared to the opposite side of the suction port in the rotation axis direction.

Also, in the impeller of a centrifugal multiblade fan, if there is a large deviation (incident angle) between the inlet angle (inlet condition) of the inner peripheral edge of the blade and the inflow angle (inflow condition) of the air flowing into the blade, There is a tendency that the air flow is separated and stalled in the space, and the smaller the incident angle, the closer to the ideal state.

However, in a normal impeller, the inlet angle of the inner peripheral edge of the blade on the suction port side where the flow of air flowing into the blade changes suddenly is opposite to the suction port where the flow of air flowing into the blade changes slowly. Varies greatly with respect to the entrance angle at. For this reason, on the suction port side of the impeller, the deviation between the inflow condition of the air flowing into the inner peripheral edge and the inflow condition of the air flowing into the blade tends to increase, and the air flow is separated in the space between the blades on the suction port side. Is likely to occur.

On the other hand, for example, in Patent Document 1, as shown in FIG. 21, the inner diameter of the impeller 100 on the side plate 130 side (suction port side) is larger than the main plate 120 side (opposite side of the suction port). The inner peripheral edge 111 of the blade 110 on the side plate 130 side is tapered. As a result, the airflow resistance on the suction port side of the impeller 100 is reduced, and the air flowing from the rotation axis direction can easily flow into the space between the blades near the suction port.

Further, in Patent Document 1, it is assumed that the substantial inflow angle of the air flowing into the blade 110 is constant regardless of the position in the rotation axis direction, and a predetermined direction (for example, a vertical direction) with respect to the inner peripheral edge 111 of the blade 110. ) Is set to within ± 5 ° on each cross-section that intersects. Thereby, the difference between the inlet angle and the inflow angle in the inner peripheral edge 111 on the side plate 130 side is reduced, and separation of the air flow on the side plate 130 side is suppressed. 21 is a meridional view corresponding to the impeller 100 illustrated in FIG. Here, the meridian plane is a plane obtained by rotationally projecting the shape of the blade on the cross section including the rotation axis of the impeller.

JP 2006-200955 A

In the impeller 100 of the above-described prior art, air easily flows into the space between the blades near the side plate 130, but it is still difficult to sufficiently suppress the separation of the air flow on the side plate 130 side. There is a problem that a flow velocity distribution occurs on the 100 air outlet side.

Hereinafter, this point will be described with reference to the drawings. 22 and 23 are explanatory diagrams for explaining the problems of the conventional technology. 22 is a cross-sectional view taken along the line XXII-XXII of FIG. 21 (cross-sectional view of the blade 110 on the main plate 120 side), and FIG. 23 is a cross-sectional view taken along the line XXIII-XXIII of FIG. 22 and FIG. 23, the inlet angle α of each blade 110 is set to the tangent line of the inscribed circle passing through the inner peripheral edge portion 111 of each blade (one-dot chain line in the drawing) and the pressure surface 110a side of the inner peripheral edge portion 111. The angle formed with the tangent line (two-dot chain line in the figure) at the inner end of the.

In the prior art impeller 100, since the inner diameter of the impeller 100 on the side plate 130 side is larger than that on the main plate 120 side, the peripheral speed Us ′ on the side plate 130 side is higher than the peripheral speed Um ′ on the main plate 120 side. It becomes faster (Us '> Um').

Further, in the impeller 100, as shown by a broken line arrow in FIG. 21, a change in the flow direction of the air flowing into the inter-blade space on the side plate 130 side is larger than that on the main plate 120 side. Therefore, as shown in FIGS. 22 and 23, the absolute inflow velocity Cs ′ of the air flowing into the inner peripheral edge 111 of the blade 110 on the side plate 130 side flows into the inner peripheral edge 111 of the blade 110 on the main plate 120 side. It becomes slower than the absolute inflow velocity Cm ′ of air (Cs ′ <Cm ′).

Here, when the angle formed between the relative inflow velocity V of air obtained by combining the peripheral velocity component and the absolute inflow velocity component and the peripheral velocity component is defined as an inflow angle β, as shown in FIGS. The inflow angle βs ′ on the side plate 130 side becomes smaller than the inflow angle βm ′ on the main plate 120 side.

For this reason, when the entrance angle αs ′ on the side plate 130 side is aligned with the entrance angle αm ′ on the main plate 120 side as in the conventional impeller 100, the entrance angle αs ′ and the inflow angle βs ′ on the side plate 130 side (Incident angle γs ′) becomes larger than the incident angle γm ′ on the main plate 120 side.

Thus, even with the prior art impeller 100, the incident angle γs ′ on the side plate 130 side is still larger than the incident angle γm ′ on the main plate 120 side, and air flow separation on the side plate 130 side is sufficiently suppressed. It is difficult. And by the separation of the air flow on the side plate 130 side, the flow velocity on the side plate 130 side on the air outlet side of the impeller 100 decreases.

As a result, for example, as shown in the flow velocity distribution on the right side of the impeller 100 in FIG. 21, a flow velocity distribution in which the flow velocity on the side plate 130 side becomes slower than that on the main plate 120 side on the air outlet side of the impeller 100 occurs. .

Such a problem also occurs in the impeller 100 in which the inner diameter on the side plate 130 side is the same as that on the main plate 120 side, that is, in the impeller 100 in which the inner peripheral edge 111 is not tapered. In the impeller 100 in which the inner peripheral edge 111 is not tapered, the absolute inflow speed Cs ′ on the side plate 130 side becomes slower than the main plate 120 side, so that the inflow angle βs ′ on the side plate 130 side becomes the inflow on the main plate 120 side. This is because it becomes smaller with respect to the angle βm ′.

In view of the above points, an object of the present disclosure is to provide a centrifugal multiblade fan capable of sufficiently equalizing the flow velocity distribution in the rotation axis direction on the air outlet side of the impeller.

In order to achieve the above object, the present inventors made extensive studies. As a result, in the centrifugal multiblade blower, focusing on the fact that the flow rate on the air outlet side of the impeller increases in proportion to the square of the outer diameter of the impeller under conditions where the rotational speed and the ventilation resistance are constant, A centrifugal multiblade fan has been devised that can achieve uniform flow velocity distribution on the air outlet side of the impeller.

In one aspect of the present disclosure, an impeller includes a main plate coupled to the rotation shaft, a plurality of blades disposed around the axis of the rotation shaft, and the other end of the rotation shaft coupled to the main plate, and a rotation A plurality of blades on one end side of the shaft, and the plurality of blades intersect each inner peripheral edge of the plurality of blades on the meridian surface of the impeller in a predetermined direction. The entrance angle on the cross section is uniform over the entire area from the side plate side to the main plate side, and the outer peripheral edges of the plurality of blades are separated from the axis of the rotation axis from the main plate side to the side plate side. It is characterized by being composed.

In this way, in the configuration in which the inlet angle is uniform over the entire region from the side plate side to the main plate side, the outer peripheral diameter of the impeller is larger on the side plate side than the main plate side, so that the air outlet side on the side plate side of the impeller is The flow rate can be increased. Thereby, the flow velocity on the air outlet side on the side plate side of the impeller can be increased as compared with the impeller of the prior art.

Furthermore, the flow rate of the inflow air to the inner peripheral edge on the side plate side increases as the flow rate on the air outlet side on the side plate side of the impeller increases. Since the increase in the flow rate of the inflow air to the inner peripheral edge on the side plate side acts on the side where the flow velocity (absolute inflow velocity) on the side plate side increases, the inflow angle on the side plate side can be made closer to the entrance angle.

This makes it possible to suppress the separation of the air flow on the side plate side as compared with the impeller of the prior art, and to alleviate the decrease in the flow velocity on the air outlet side on the side plate side due to the separation of the air flow on the side plate side.

From the above, according to the centrifugal multiblade fan of the present disclosure, it is possible to sufficiently uniform the flow velocity distribution in the rotation axis direction on the air outlet side of the impeller, which is a problem in the impeller of the prior art. Become.

Here, “uniform” means a state where there is no deviation in the entrance angle in the entire region from the side plate side to the main plate side, or a state where there is only a minute deviation within ± 5 °. The “meridian plane” is a plane obtained by rotationally projecting the shape of the blade on a cross section including the rotation axis of the impeller. Further, the “entrance angle” is an intersection angle between a tangent line of a circle (inscribed circle) passing through each of the inner peripheral edge portions of the plurality of blades and the inner peripheral edge portion of the blades in the radial direction of the rotation axis.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
It is a mimetic diagram of an air-conditioner for vehicles provided with a fan concerning a 1st embodiment. It is a perspective view of the impeller of the air blower concerning a 1st embodiment. It is a half sectional view of the impeller of the air blower concerning a 1st embodiment. It is IV arrow line view which shows the blade | wing part shown in FIG. FIG. 4 is a V arrow view showing the blade portion shown in FIG. 3. FIG. 4 is a VI arrow view showing a blade portion shown in FIG. 3. It is a meridional view of the whole impeller which concerns on 1st Embodiment. It is a meridian view of the principal part of the impeller which concerns on 1st Embodiment. It is IX-IX sectional drawing in FIG. FIG. 9 is a sectional view taken along line XX in FIG. It is a perspective view of the impeller of the air blower concerning a 2nd embodiment. It is a half sectional view of the impeller of the air blower concerning a 2nd embodiment. It is a top view of the impeller of the air blower concerning a 2nd embodiment. It is a meridian view of the impeller of the air blower concerning 2nd Embodiment. It is a meridian view of the impeller of the air blower which concerns on 3rd Embodiment. It is a meridian view of the impeller principal part of the air blower concerning 4th Embodiment. It is a meridional view of the impeller of the air blower which concerns on a modification. It is a meridional view of the impeller of the air blower which concerns on a modification. It is a perspective view of the impeller of the air blower concerning a modification. It is a half sectional view of the impeller of the air blower concerning a modification. It is a meridian view which shows the principal part of the impeller of a prior art. FIG. 22 is a sectional view taken along line XXII-XXII in FIG. 21. FIG. 23 is a sectional view taken along line XXIII-XXIII in FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent parts may be denoted by the same reference numerals and description thereof may be omitted.
(First embodiment)
A first embodiment will be described. In this embodiment, the centrifugal multiblade fan according to the present disclosure is applied to an air conditioner 1 for a vehicle equipped with a water-cooled engine.

As shown in FIG. 1, the air conditioner 1 has an air conditioning casing 2 that forms an air flow path of blown air that is blown into the vehicle interior. At the most upstream side of the air flow casing 2 in the air conditioning casing 2, an inside air introduction port 3 for introducing inside air (vehicle compartment air) and an outside air introduction port 4 for introducing outside air (vehicle compartment outside air) are formed. In addition, an inside / outside air switching door 5 for selectively opening and closing each of the introduction ports 3 and 4 is provided.

A blower 7 is arranged on the downstream side of the air flow of the inside / outside air switching door 5, and air introduced from the introduction ports 3, 4 by the blower 7 is supplied to the outlets 14, 15, 17 described later. It is blown toward.

The blower 7 is a centrifugal multi-blade blower that blows inhaled air from the direction of the rotation axis toward the outside in the radial direction. In the present embodiment, as the blower 7, a single suction type blower that blows out air sucked from one end side in the rotation axis direction toward the radially outer side is adopted.

The blower 7 has an impeller 7a, a scroll casing (casing) 7b, and an electric motor 7c that drives the impeller 7a. The impeller 7a rotates around the rotating shaft 70 and blows air outward in the radial direction, and is made of resin. The scroll casing 7b accommodates the impeller 7a and forms a spiral flow path for collecting air blown from the impeller 7a. The scroll casing 7b is formed with a suction port 74 that opens to one end of the rotary shaft 70. In addition, the detail of the impeller 7a of the air blower 7 which concerns on this embodiment is mentioned later.

Further, an evaporator 9 is disposed on the downstream side of the air flow of the blower 7, and all the air blown to the blower 7 passes through this evaporator 9. The evaporator 9 of the present embodiment is an air cooling means that cools the blown air by exchanging heat between the refrigerant flowing through the evaporator 9 and the blown air blown from the blower 7. The evaporator 9 constitutes a vapor compression refrigeration cycle together with a compressor, a condenser, a gas-liquid separator, an expansion valve and the like (not shown).

A heater core 10 is disposed on the downstream side of the air flow of the evaporator 9. The heater core 10 is an air heating unit that heats the air that has passed through the evaporator 9 by exchanging heat between the engine coolant that cools the engine 11 and the air that has passed through the evaporator 9.

Further, a bypass passage 12 is formed in the air conditioning casing 2 so that the air after passing through the evaporator 9 flows around the heater core 10. Then, on the upstream side of the air flow of the heater core 10, the air volume ratio between the air volume passing through the heater core 10 and the air volume passing through the bypass passage 12 is adjusted to adjust the temperature of the air blown into the vehicle interior. An air mix door 13 is provided.

Further, at the most downstream portion of the air flow of the air conditioning casing 2, a face outlet 14 for blowing air toward the upper body of the occupant, a foot outlet 15 for blowing air toward the feet of the occupant, and a window glass 16. The defroster blower outlet 17 for blowing air toward the inner surface is formed.

Blowing mode switching doors 18, 19, and 20 are disposed on the upstream side of the airflows of the blowout ports 14, 15, and 17, respectively. By switching and opening these blow mode switching doors 18 to 20, the face mode that blows air toward the upper body of the occupant, the foot mode that blows air toward the lower half of the occupant, and the air toward the inner surface of the vehicle window glass. Switch defroster mode to blow out.

Then, the impeller 7a of the air blower 7 of this embodiment is demonstrated. As shown in the perspective view of FIG. 2 and the half cross-sectional view of FIG. 3, the impeller 7 a of the blower 7 includes a plurality of blades 71, side plates 72, and a main plate 73.

The main plate 73 is composed of a disk-shaped member coupled to the rotating shaft 70. The main plate 73 of this embodiment is connected to a portion 71b on the other end side (the lower side in the drawing) of each blade 71 in the rotation axis direction, and is configured to overlap each blade 71 when viewed from the rotation axis direction. Has been.

The side plate 72 is connected to a radially outer portion of the rotary shaft 70 on one end side (upper side in the drawing) of each blade 71 in the rotary axis direction. The side plate 72 of the present embodiment is connected so as to cover the outer peripheral edge (blade trailing edge) 712 on one end side in the rotational axis direction of each blade 71 from the radially outer side of the rotational shaft 70. More specifically, the side plate 72 of the present embodiment has an annular shape (a shroud shape) that is curved so that a portion on one end side in the rotation axis direction is positioned on a radially inner side of the rotation shaft 70 relative to a portion on the other end side. It has become. Note that the side plate 72 of the present embodiment is configured such that the inner peripheral diameter Ds thereof is larger than the outer peripheral diameter Dm of the main plate 73, and has a shape that does not overlap with the main plate 73 when viewed from the direction of the rotation axis. ing.

Each blade 71 is disposed around the axis Z of the rotating shaft 70. Each blade 71, side plate 72, and main plate 73 constituting the impeller 7a are integrally formed by resin molding or the like.

The impeller 7a configured as described above is the air that flows into the inter-blade space (the space between the blades 71) in the impeller 7a from the suction port 74 on one end side in the rotation axis direction due to the rotation of the rotation shaft 70. Are blown out radially outward of the impeller 7a by centrifugal force.

Subsequently, the shape of the blade 71 of the present embodiment will be described. 4 to 6 are views taken along arrows in FIG. 3, and show the shape of the blade 71 of the present embodiment. For convenience of explanation, the side plate 72 and the main plate 73 are not shown in FIGS. 4 to 6, and three typical blades 71 in the directions of arrows A to C in FIG. 3 are shown. Yes.

As shown in FIG. 4, each blade 71 has an inner peripheral edge (blade leading edge) 711 formed between the portions 71a and 71b at both ends of the blade 71 on the inner peripheral side of the impeller 7a. Further, as shown in FIG. 5, each blade 71 has an outer peripheral edge portion (blade trailing edge) 712 between portions 71 a and 71 b at both ends of the blade 71 on the outer peripheral side of the impeller 7 a.

As shown in FIG. 6, each blade 71 of the present embodiment has a portion 711 a on one end side in the rotation axis direction in the inner peripheral edge portion 711 in addition to the rotation axis direction in the inner peripheral edge portion 711. It is located in front of the rotation direction R of the impeller 7a rather than the part 711b on the end side.

As described above, the impeller 7a of the present embodiment is configured to blow out the air sucked from the rotation axis direction toward the radially outer side. For this reason, by positioning the portion 711a on the one end side in the rotation axis direction in the inner peripheral edge 711 in front of the portion 711b on the other end side in the rotation axis direction in the inner peripheral edge 711, the side plate 72 side It becomes easy to suck air into the space between the blades from the rotation axis direction. As a result, the flow rate of air flowing into the space between the blades on the side plate 72 side can be increased. In the following, the part 711a on one end side in the rotation axis direction in the inner peripheral edge 711 may be referred to as a forward movement part 711a, and the part 711b on the other end side in the rotation axis direction in the inner peripheral edge 711 may be referred to as a backward movement part 711b. .

Subsequently, specific shapes of the inner peripheral edge portion 711 and the outer peripheral edge portion 712 of each blade 71 will be described with reference to meridional views of FIGS. The “meridional surface” is a surface obtained by rotationally projecting the shape of the blade 71 on a cross section including the rotation shaft 70 in the impeller 7a.

As shown in FIGS. 7 and 8, the inner peripheral edge 711 of the blade 71 of the present embodiment is such that the inner peripheral diameter on the side plate 72 side of the impeller 7 a is larger than the inner peripheral diameter on the main plate 73 side. It is configured to be separated from the axis Z of the rotary shaft 70 from the 73 side toward the side plate 72 side. The inner peripheral diameter of the impeller 7 a is a diameter of an inscribed circle that passes through the inner peripheral edge 711 of each blade 71 in the radial direction of the rotating shaft 70.

By the way, in the centrifugal multiblade blower, if the difference (incidence angle γ) between the inlet angle α at the inner peripheral edge 711 of the blade 71 and the inflow angle β of air flowing into the inner peripheral edge 711 is large, the space between the blades is reduced. Since the separation region is formed and stalls, the smaller the incident angle γ, the more ideal the state becomes.

However, in a normal centrifugal multiblade fan, the difference between the inlet angle α and the inflow angle β at the inner peripheral edge 711 on the side plate 72 side is likely to be larger than that on the main plate 73 side, and the interblade space on the side plate 72 side is larger. Therefore, the air flow tends to be peeled off.

Therefore, in the present embodiment, the entrance angle α on each cross section intersecting in a predetermined direction with respect to the inner peripheral edge portion 711 of the blade 71 appearing on the meridional surface of the impeller 7a extends from the side plate 72 side to the main plate 73 side. It is set to be uniform throughout the entire area. “Uniform” means a state where there is no deviation in the entrance angle α in the entire region from the side plate 72 side to the main plate 73 side, or a state where there is only a minute deviation within ± 5 °.

Here, FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8, and FIG. 10 is a cross-sectional view taken along the line XX in FIG. The IX-IX cross section is a cross section when a portion of the blade 71 on the main plate 73 side is cut in a direction perpendicular to the rotation axis direction. Further, the XX cross section is a cross section when the portion of the side plate 72 in the blade 71 is cut in a direction orthogonal to the axial direction of the rotation axis.

Specifically, in the present embodiment, as shown in FIGS. 9 and 10, the side plates 72 represent the entrance angles αm and αs in each cross section orthogonal to the rotation axis direction at the inner peripheral edge 711 of each blade 71. An angle that is uniform over the entire area from the side to the main plate 73 side (for example, an angle of 55 ° to 76 °) is set.

In the present embodiment, the entrance angles αm and αs are tangent to the inscribed circle (the dashed line in FIGS. 9 and 10) passing through the inner peripheral edge 711 of the blade 71 and the inner end 713 a of the blade 71 on the positive pressure surface 713 side. The angle formed by the tangent line (two-dot chain line in FIGS. 9 and 10).

Here, as explained as the above problem, the air flow on the side plate 72 side can be obtained only by making the inlet angles αm and αs of the inner peripheral edge 711 of each blade 71 uniform over the entire region from the side plate 72 side to the main plate 73 side. It is difficult to sufficiently suppress peeling.

For this reason, in this embodiment, as shown in FIG. 7, the outer peripheral edge portion 712 of each blade 71 is arranged on the main plate 73 so that the outer peripheral diameter on the side plate 72 side in the impeller 7 a is larger than the outer peripheral diameter on the main plate 73 side. The shape is separated from the axis Z of the rotary shaft 70 from the side toward the side plate 72 side. The outer peripheral diameter of the impeller 7 a is the diameter of a circumscribed circle passing through the outer peripheral edge 712 of each blade 71 in the radial direction of the rotating shaft 70.

Specifically, the blade 71 of the present embodiment is configured such that the inner peripheral diameter increases from the main plate 73 side to the side plate 72 side, and the outer peripheral diameter increases from the main plate 73 side to the side plate 72 side. (D1> d2, D1> D2). Thereby, as for the impeller 7a of this embodiment, the outer shape becomes a reverse trapezoid shape.

Furthermore, in this embodiment, the side plate side inner / outer diameter ratio is smaller than the main plate side inner / outer diameter ratio. The side plate side inner / outer diameter ratio is the ratio of the outer peripheral diameter D1 to the inner peripheral diameter d1 on the side plate 72 side of the impeller 7a (= D1 / d1), and the main plate side inner / outer diameter ratio is the inner peripheral diameter on the main plate 73 side. It is a ratio (D2 / d2) of the outer peripheral diameter D2 to d2.

Next, the operation of the air conditioner 1 of this embodiment will be described. When the operation of the air conditioner 1 is started by an occupant's operation or the like, the air introduced into the air conditioning casing 2 through the inlets 3 and 4 is directed to the outlets 14, 15, and 17 by the blower 7. And blown. The blown air blown by the blower 7 is adjusted to a desired temperature by the evaporator 9, the heater core 10, and the air mix door 13, and blown out from any one of the outlets 14, 15, and 17 into the vehicle interior. Is done.

Here, in the blower 7 of the present embodiment, the inner peripheral edge 711 of the blade 71 is moved from the main plate 73 side to the side plate 72 side so that the inner peripheral diameter of the impeller 7a increases from the main plate 73 side toward the side plate 72 side. The shape is away from the axis Z of the rotating shaft 70. Thereby, the ventilation resistance in the side plate 72 side of the impeller 7a can be reduced, and the air flowing from the rotation axis direction can easily flow into the space between the blades on the side plate 72 side.

Further, in the blower 7 of the present embodiment, the inlet angles αm and αs in each cross section orthogonal to the axis of the rotation shaft 70 in the inner peripheral edge 711 of each blade 71 are set over the entire region from the side plate 72 side to the main plate 73 side. The angle is uniform. Thereby, compared with a normal centrifugal multiblade fan, separation of the air flow on the side plate 72 side can be suppressed, and the air flowing from the rotation axis direction can be easily flowed to the space between the blades near the suction port 74.

Furthermore, in the blower 7 of the present embodiment, the outer peripheral edge 712 of the blade 71 has a shape that is separated from the axis Z of the rotary shaft 70 from the main plate 73 side toward the side plate 72 side. As a result, the rotational axis direction on the air outlet side of the impeller 7a, which becomes a problem when the inlet angles αm and αs of the inner peripheral edge portion 711 of each blade 71 are uniform over the entire region from the side plate 72 side to the main plate 73 side, The flow velocity distribution is uniform.

Describing this point, in the centrifugal multiblade fan, the flow rate on the air outlet side of the impeller 7a increases by the square of the outer diameter under conditions where the rotational speed and the ventilation resistance are constant. For this reason, by enlarging the outer peripheral diameter of the impeller 7a on the side plate 72 side rather than the main plate 73 side, the flow rate on the air outlet side on the side plate 72 side of the impeller 7a increases, and accordingly the side plate of the impeller 7a. The flow velocity on the air outlet side on the 72 side becomes faster. That is, the flow rate on the side plate 72 side on the air outlet side of the impeller 7a can be made closer to the flow rate on the main plate 73 side.

Furthermore, the flow rate of the inflow air to the inner peripheral edge 711 on the side plate 72 side increases as the flow rate on the air outlet side on the side plate 72 side of the impeller 7a increases. The increase in the flow rate of the inflow air to the inner peripheral edge 711 on the side plate 72 side acts to increase the flow velocity on the side plate 72 side, so that the difference between the inlet angle and the inflow angle on the side plate 72 side can be reduced. .

That is, in this embodiment, since the inner diameter of the impeller 7a on the side plate 72 side is larger than that on the main plate 73 side, the peripheral speed Us on the side plate 72 side is set to the main plate 73 as shown in FIGS. It becomes faster than the peripheral speed Um on the side (Us> Um).

On the other hand, the absolute inflow speed of the air flowing into the inner peripheral edge portion 711 of the blade 71 on the side plate 72 side is a speed that is faster by the increase Cp of the flow velocity accompanying the increase in the flow rate of the inflowing air to the inner peripheral edge portion 711 (= Cs + Cp )

Here, when the angle formed by the relative inflow velocity V of air obtained by combining the peripheral velocity component and the inflow velocity component and the peripheral velocity component is defined as the inflow angle β, the inflow angle βs on the side plate 72 side is the main plate 73. This is an angle close to the inflow angle βm on the side.

In the impeller 7a of the present embodiment, the entrance angle αs on the side plate 72 side is aligned with the entrance angle αm on the main plate 73 side, so the difference (incident angle γs) between the entrance angle αs and the inflow angle βs on the side plate 72 side is. Reduced.

Thereby, separation of the air flow on the side plate 72 side is sufficiently suppressed, so that a decrease in the flow velocity on the air outlet side on the side plate 72 side due to separation of the air flow on the side plate 72 side can be mitigated. For this reason, the flow velocity on the side plate 72 side on the air outlet side of the impeller 7a can be made closer to the flow velocity on the main plate 73 side.

As a result, for example, the flow velocity distribution in the direction of the rotation axis on the air outlet side of the impeller 7a can be sufficiently uniformed like the flow velocity distribution shown on the right side of the impeller 7a in FIG. In addition, noise suppression can be achieved.

Particularly, in the present embodiment, a portion 711a on one end side in the rotation axis direction in the inner peripheral edge portion 711 is positioned in front of the portion 711b on the other end side in the rotation axis direction in the rotation direction R.

According to this, the flow rate of air flowing into the inner peripheral edge 711 on the side plate 72 side (absolute inflow rate) can be increased by increasing the flow rate of air flowing into the interblade space on the side plate 72 side. The incident angle γs on the 72 side can be further reduced. As a result, separation of the air flow on the side plate 72 side can be more effectively suppressed.
(Second Embodiment)
Next, a second embodiment will be described. This embodiment demonstrates the example which changed the shape of the main board 73 with respect to 1st Embodiment. In the present embodiment, description of the same or equivalent parts as in the first embodiment will be omitted or simplified.

As shown in the perspective view of FIG. 11, the half sectional view of FIG. 12, and the top view of FIG. 13, the impeller 7a of this embodiment has a smaller outer diameter of the main plate 73 than the first embodiment. . Specifically, in this embodiment, as shown in FIG. 13, when the impeller 7a is viewed from the direction of the rotation axis, the main plate 73 and the advancing portion 711a in the inner peripheral edge 711 do not overlap each other. The outer peripheral diameter of 73 is made small.

More specifically, as shown in the meridional view of FIG. 14, the distance L1 from the axis Z of the rotating shaft 70 to the outer peripheral end of the main plate 73 is from the axis Z of the rotating shaft 70 to the advance portion 711a in the inner peripheral edge 711. It is smaller than the distance L2.

Other configurations are the same as those in the first embodiment. Therefore, according to the air blower 7 of this embodiment, there exists an effect equivalent to 1st Embodiment.

Here, when the forward part 711a in the inner peripheral edge 711 is configured to be positioned in front of the backward part 711b in the rotational direction R (three-dimensional wing), each blade 71, side plate 72, and main plate 73 are integrally formed. There is a possibility that the forward movement portion 711a becomes undercut.

On the other hand, in the present embodiment, the outer diameter of the main plate 73 is reduced so that the main plate 73 and the forward movement portion 711a in the inner peripheral edge 711 do not overlap in the rotation axis direction. For this reason, when at least the main plate 73 and each blade 71 are integrally formed by molding, the molded product can be taken out from the mold by sliding the mold in the direction of the rotation axis. As a result, the impeller 7a can be easily manufactured, and the cost can be reduced.
(Third embodiment)
Next, a third embodiment will be described. This embodiment demonstrates the example which changed the shape of the impeller 7a with respect to 1st, 2nd embodiment. In the present embodiment, description of the same or equivalent parts as in the first and second embodiments will be omitted or simplified.

In this embodiment, as shown in FIG. 15, the ratio of the outer peripheral diameter D1 to the inner peripheral diameter d1 on the side plate 72 side of the impeller 7a (side plate side inner / outer diameter ratio) is set to the outer peripheral diameter with respect to the inner peripheral diameter d2 on the main plate 73 side. The ratio is larger than the ratio of D2 (main plate side inner / outer diameter ratio) (D1 / d1> D2 / d2).

Specifically, in the present embodiment, the outer peripheral edge 712 of the blade 71 is configured to be separated from the axis Z of the rotary shaft 70 from the main plate 73 side to the side plate 72 side, and the inner peripheral edge 711 of the blade 71 is set in the rotational axis direction. It is set as the structure extended along. That is, the impeller 7a of the present embodiment has an outer peripheral diameter on the side plate 72 side larger than an outer peripheral diameter on the main plate 73 side, and the inner peripheral diameter on the side plate 72 side and the inner peripheral diameter on the main plate 73 side in the impeller 7a are equal. It has become.

Other configurations are the same as those in the first embodiment, and according to the blower 7 of the present embodiment, the same effects as those of the first embodiment are achieved.

Here, as in the first embodiment, when the side plate side inner / outer diameter ratio (= D1 / d1) is smaller than the main plate side inner / outer diameter ratio (D2 / d2), the inner periphery of the impeller 7a on the side plate 72 side. If the diameter becomes too large, the peripheral speed Us at the inner peripheral edge 711 on the side plate 72 side will increase. As a result, the inflow angle βs at the inner peripheral edge 711 on the side plate 72 side becomes small, and the difference between the inlet angle αs and the inflow angle βs at the inner peripheral edge 711 on the side plate 72 side may increase.

On the other hand, in this embodiment, since the side plate side inner / outer diameter ratio of the impeller 7a is larger than the main plate side inner / outer diameter ratio, the inner peripheral diameter of the impeller 7a on the side plate 72 side does not become too large. An increase in the peripheral speed Us at the inner peripheral edge 711 on the side plate 72 side can be suppressed. That is, according to the configuration of the present embodiment, in addition to the increase in the flow rate on the side plate 72 side, the increase in the peripheral speed at the inner peripheral edge portion 711 on the side plate 72 side that affects the inflow angle at the inner peripheral edge portion 711 on the side plate 72 side. It becomes possible to suppress.

As a result, the inflow angle βs at the inner peripheral edge 711 on the side plate 72 side is increased, and the difference between the inlet angle αs and the inflow angle βs at the inner peripheral edge 711 on the side plate 72 side is reduced. It becomes possible to suppress effectively.
(Fourth embodiment)
Next, a fourth embodiment will be described. In the present embodiment, description of the same or equivalent parts as in the first to third embodiments will be omitted or simplified.

In the present embodiment, a plurality of virtual streamlines imagining the flow direction of the air flowing into the inner peripheral edge 711 of the blade 71 are set, and the inlet angle α in each cross section on the virtual streamlines is changed from the side plate 72 side to the main plate 73 side. The angle is uniform over the entire area (for example, an angle of 55 ° to 76 °).

Specifically, in the present embodiment, as shown in FIG. 16, the first to sixth dividing lines Yd1 to Yd6 are set as virtual streamlines, and the entrances on the respective cross sections on the virtual streamlines Yd1 to Yd6. The angle α is a uniform angle over the entire range of the inner peripheral edge 711 of the blade 71.

Here, the setting of the virtual streamline will be described. The inner peripheral edge 711 of the blade 71 is divided into a predetermined number so that the length along the inner peripheral edge 711 of the blade 71 is equal, and the inner peripheral edge 711 is divided. Set the point Yin. In the present embodiment, the dividing point Yin at the inner peripheral edge 711 is set in order from the one end side in the rotation axis direction of the blade 71 in order from the first inner peripheral dividing point Yi1, the second inner peripheral dividing point Yi2,. , The sixth inner circumference side dividing point Yi6 is set.

Similarly, the outer peripheral edge 712 of the blade 71 is divided into a predetermined number so that the length along the outer peripheral edge 712 of the blade 71 is uniform, and a dividing point Yon at the outer peripheral edge 712 is set. In this embodiment, the dividing point Yon of the outer peripheral edge portion 712 is divided into the first outer peripheral side dividing point Yo1, the second outer peripheral side dividing point Yo2,. It is set as 6 outer peripheral side dividing points Yo6.

Of the inner circumferential side dividing point Yin and the outer circumferential side dividing point Yon, when counting sequentially from one end side in the rotation axis direction of the blade 71, lines connecting the same division points (first to sixth lines). The dividing lines Yd1 to Yd6) are set as virtual streamlines.

Other configurations are the same as those of the first embodiment, and the blower 7 of the present embodiment has the same effects as those of the first embodiment. Furthermore, according to the blower 7 of this embodiment, there exists an advantage that the design surface of the blade | wing 71 does not cross | intersect and it becomes easy to design the blade | wing 71 in the impeller 7a.

In the present embodiment, the example in which the inner peripheral edge 711 and the outer peripheral edge 712 of the blade 71 are divided into six and six virtual streamlines are set has been described. The set number may be set to an arbitrary number (for example, 10).

The embodiment of the present disclosure has been described above, but the present disclosure is not limited thereto, and various modifications can be made as follows, for example, without departing from the scope described in each claim.

(1) In each of the above-described embodiments, as the shape of the blade 71, the portion 711a on one end side in the rotation axis direction of the inner peripheral edge 711 is in the rotation direction of the impeller 7a rather than the portion 711b on the other end side in the rotation axis direction. Although the example located ahead of R was demonstrated, it is not limited to this. For example, you may employ | adopt the blade | wing 71 located in the back of the rotation direction R of the impeller 7a in the position of the inner peripheral edge part 711 toward the side plate 72 side from the main plate 73 side.

(2) In each of the above-described embodiments, the side plate 72 is an annular shape that is curved so that a portion on one end side in the rotation axis direction is positioned on the radially inner side of the rotation shaft 70 relative to a portion on the other end side. Although described, it is not limited to this. For example, as shown in FIG. 17, the side plate 72 may have an annular shape extending along the rotation axis direction, and may be connected to an outer peripheral edge portion 712 existing on the radially outer side at one end side in the rotation axis direction of each blade 71. .

Further, in each of the above-described embodiments, the example in which the side plate 72 is connected so as to cover the outer peripheral edge portion 712 of each blade 71 from the radially outer side of the rotating shaft 70 has been described, but the present invention is not limited to this. For example, as shown in FIG. 18, the side plate 72 may be connected to a portion 71 a on one end side in the rotation axis direction of each blade 71.

Whichever shape is adopted, when the main plate 73 and the side plate 72 are viewed from the direction of the rotation axis so as not to cause undercut when the impeller 7a is integrally formed, they do not overlap each other. It is desirable to make it. Of course, as long as the impeller 7a can be integrally formed, the main plate 73 and the side plate 72 may be configured to overlap when viewed from the rotation axis direction.

(3) In the above-described third embodiment, the example in which the inner peripheral edge 711 of the blade 71 extends along the rotation axis direction has been described, but the side plate side inner / outer diameter ratio of the impeller 7a is the main plate side inner / outer diameter ratio. If it is a bigger structure, it is good also as a structure which leaves | separates the inner peripheral edge part 711 of the blade | wing 71 from the axis line Z of the rotating shaft 70 toward the side plate 72 side from the main plate 73 side.

(4) In each of the above-described embodiments, an example in which a single suction type blower is employed as the blower 7 has been described. However, the present invention is not limited thereto, and a double suction type blower that sucks air from both sides in the rotation axis direction is employed. Also good.

In this case, for example, as shown in FIGS. 19 and 20, first and second impeller parts 7aa and 7ab configured in the same manner as the impeller 7a described in the above-described embodiments are prepared. The main plates 73a and 73b of the portions 7aa and 7ab may be connected by the connecting member 75.

In addition, each blade | wing 71 in each impeller part 7aa and 7ab has the entrance angle (alpha) on each cross section which cross | intersects the predetermined direction with respect to the inner peripheral part 711 on the meridian surface of the impeller 7a side plate 72a, 72b side To the main plates 73a and 73b. Further, it is assumed that the outer peripheral edge 712 of the blade 71 in each impeller portion 7aa, 7ab is configured to be separated from the axis Z of the rotary shaft 70 from the main plate 73a, 73b side toward the side plate 72a, 72b side.

(5) In the first embodiment described above, the entrance angle α on each cross section orthogonal to the rotational axis direction on the meridional surface of the impeller 7a is made uniform over the entire region from the side plate 72 side to the main plate 73 side. However, the present invention is not limited to this. For example, the entrance angle α on each cross section orthogonal to the inner peripheral edge 711 on the meridian surface of the impeller 7a may be uniform over the entire region from the side plate 72 side to the main plate 73 side.

(6) In each of the above-described embodiments, the example in which the blower 7 is applied to the vehicle air conditioner 1 has been described, but the present invention may be applied not only to the vehicle but also to other air conditioners.

(7) The above-described embodiments are not irrelevant and can be combined as appropriate unless the combination is clearly impossible. In each of the above-described embodiments, elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Needless to say.

Further, in each of the above-described embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly indicated that it is particularly essential and clearly specified in principle. It is not limited to the specific number except in a limited case.

Furthermore, in each of the above-described embodiments, when referring to the shape, positional relationship, etc. of the component, etc., unless specifically stated or limited in principle to a specific shape, positional relationship, etc. The positional relationship is not limited.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims (8)

1. The casing (7b), which includes an impeller (7a) that rotates about the rotation shaft (70), and a casing (7b) that houses the impeller (7a), and that opens at least on one end side of the rotation shaft (70). In the centrifugal multiblade blower that blows out the air sucked from the suction port (74) toward the radially outer side of the rotating shaft (70),
   The impeller (7a)
   A main plate (73) coupled to the rotating shaft (70);
   A plurality of blades (71) disposed around the axis of the rotary shaft (70) and connected to the main plate (73) at the other end of the rotary shaft (70);
   A side plate (72) connecting the plurality of blades (71) on one end side of the rotating shaft (70),
   The plurality of blades (71) are on a cross section intersecting in a predetermined direction with respect to respective inner peripheral edges (711) of the plurality of blades (71) on the meridional surface of the impeller (7a). The entrance angle (α) is uniform over the entire area from the side plate (72) side to the main plate (73) side, and the outer peripheral edge (712) of the plurality of blades (71) is the main plate ( 73) A centrifugal multiblade fan configured to be away from the axis of the rotary shaft (70) from the side toward the side plate (72).
2. In the plurality of blades (71), a portion (711a) on one end side of the rotating shaft (70) in the inner peripheral edge (711) is in addition to the rotating shaft (70) in the inner peripheral edge (711). The centrifugal multiblade fan according to claim 1, wherein the centrifugal multiblade fan is located in front of the end portion (711b) in the rotational direction (R) of the impeller (7a).
3. The main plate (73) has a plurality of blades (71) so as not to overlap a portion of one end side (711a) of the rotation shaft (70) in the inner peripheral edge (711) in the direction of the rotation shaft (70). The centrifugal multiblade fan according to claim 2, wherein the centrifugal multiblade fan is connected to the other end of the rotating shaft (70).
4. The side plate (72) is connected to a portion (712) existing on the radially outer side of the rotation shaft (70) on one end side of the rotation shaft (70) in the plurality of blades (71). The centrifugal multiblade fan according to any one of claims 1 to 3.
5. The said side plate (72) is connected with the site | part (71a) in the one end side of the said rotating shaft (70) in the said several blade | wing (71), The one of Claim 1 thru | or 3 characterized by the above-mentioned. The centrifugal multiblade blower described in 1.
6. In the plurality of blades (71), each inlet angle (α) in a cross section orthogonal to the direction of the rotation axis (70) has a whole area extending from the side plate (72) side to the main plate (73) side. The centrifugal multiblade fan according to any one of claims 1 to 5, wherein the centrifugal multiblade fan is uniform.
7. The inner peripheral edge (711) is divided into a predetermined number so that the length along the peripheral edge is equal, and the outer peripheral edge (712) of each of the plurality of blades (71) has a length along the peripheral edge. When dividing into the predetermined number so as to be equal, a line connecting the same division points among the division points in the inner peripheral edge portion (711) and the division points in the outer peripheral edge portion (712) is virtually flowed. When a line
   Each of the plurality of blades (71) has a uniform inlet angle (α) in each cross section on the virtual streamline over the entire area from the side plate (72) side to the main plate (73) side. The centrifugal multiblade blower according to any one of claims 1 to 5, wherein the centrifugal multiblade blower is provided.
8. The ratio of the outer peripheral diameter (D1) to the inner peripheral diameter (d1) on the side plate (72) side of the impeller (7a) is the side plate side inner / outer diameter ratio (D1 / d1), and the main plate of the impeller (7a) When the ratio of the outer peripheral diameter (D2) to the inner peripheral diameter (d2) on the (73) side is the main plate side inner / outer diameter ratio (D2 / d2),
   8. The impeller (7a) according to claim 1, wherein the side plate side inner / outer diameter ratio (D1 / d1) is larger than the main plate side inner / outer diameter ratio (D2 / d2). The centrifugal multiblade blower as described in one.

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