JP2014029149A - Centrifugal multi-blade fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal multi-blade fan capable of making a sufficiently uniform distribution of the flow velocity in the rotational axis direction at the air outlet side of an impeller.SOLUTION: A centrifugal multi-blade fan comprises an impeller 7a that rotates around a rotating shaft 70 and a scroll casing 7b that houses the impeller 7a, and blows air, which is drawn from an intake port 74 formed at one end in the rotational axis direction, outward in a radial direction of a rotating shaft 70. In the centrifugal multi-blade fan, inlet angles of a blade 71 at respective cross sections which intersect an inner periphery portion 711 in prescribed directions on a meridian plane of the impeller 7a are uniform over the entire region from a side plate 72 to a main plate 73, and at least an outer periphery portion 712 of the blade 71 is configured so as to be away from the axis line of the rotating shaft 70 toward the main plate 73 side to the side plate 72 side.

Description

  The present invention relates to a centrifugal multi-blade blower that blows out air sucked from the direction of a rotating shaft toward the radially outer side of the rotating 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 2006-200525 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 impeller 100 of the prior art, 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 becomes faster than the peripheral speed Um on the main plate 120 side. (Us> Um).

  Moreover, in the impeller 100, as shown by the broken line arrow in FIG. 20, the 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. For this reason, 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 is the air flowing into the inner peripheral edge 111 of the blade 110 on the main plate 120 side. Becomes slower than the absolute inflow velocity Cm (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 is 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 is aligned with the entrance angle αm on the main plate 120 side as in the conventional impeller 100, the difference between the entrance angle αs and the inflow angle βs on the side plate 130 side (incident) Is larger than the incident angle γm on the main plate 120 side.

  As described above, even with the impeller 100 of the prior art, 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 the air flow separation on the side plate 130 side can be sufficiently suppressed. 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 angle βm on the main plate 120 side. It is because it becomes small with respect to.

  In view of the above, an object of the present invention is to provide a centrifugal multiblade fan capable of sufficiently uniforming 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 have 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.

  That is, in the invention according to claim 1, the impeller (7a) is disposed around the main plate (73) coupled to the rotating shaft and the axis of the rotating shaft, and the other end side in the rotating shaft direction is the main plate. A plurality of blades (71) connected to each other, and a side plate (72) connecting the plurality of blades on one end side in the rotation axis direction of the plurality of blades. The inlet angle on each cross section intersecting in a predetermined direction with respect to the inner peripheral edge (711) of the blade on the meridian surface is uniform over the entire area from the side plate side to the main plate side, and the outer peripheral edge of the blade The portion (712) is configured to be separated from the axis of the rotation axis from the main plate side toward the side plate side.

  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.

  In addition, 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.

  Thereby, the separation of the air flow on the side plate side can be suppressed as compared with the impeller of the prior art, and the decrease in the flow velocity on the air outlet side on the side plate side accompanying the separation of the air flow on the side plate side can be alleviated.

  From the above, according to the centrifugal multiblade fan of the present invention, 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” described in the claims means a state where there is no deviation in the entrance angle over 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.

  In addition, the code | symbol in the parenthesis of each means described in this column and the claim has shown an example of the correspondence with the specific means as described in embodiment mentioned later.

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. FIG. 4 is a view on arrow A showing a blade portion shown in FIG. 3. It is a B arrow line view which shows the blade | wing part shown in FIG. It is C arrow line view which shows the blade | wing part shown in FIG. 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. It is XX sectional drawing 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 other embodiment. It is a meridional view of the impeller of the air blower which concerns on other embodiment. It is a perspective view of the impeller of the air blower concerning other embodiments. It is a half sectional view of the impeller of the air blower concerning other embodiments. It is a meridian view which shows the principal part of the impeller of a prior art. It is XXII-XXII sectional drawing in FIG. It is XXIII-XXIII sectional drawing in FIG.

  Hereinafter, embodiments of the present invention 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 invention 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 out air sucked from the rotation axis direction 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 includes 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, the air conditioning casing 2 is provided with a bypass passage 12 through which the air that has passed 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 blowing 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 rotation 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 rotation shaft 70 on one end side (upper side in the drawing) of each blade 71 in the rotation 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 rotation 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.

  Then, the shape of the blade | wing 71 of this embodiment is demonstrated. FIGS. 4-6 is each arrow line view in FIG. 3, and has shown the shape of the blade | wing 71 of this embodiment. 4 to 6, the illustration of the side plate 72 and the main plate 73 is omitted, and three typical blades 71 in the directions of arrows A to C in FIG. 3 are illustrated. Yes.

  As shown in FIG. 4, each blade 71 has an inner peripheral edge portion (blade leading edge) 711 between portions 71 a and 72 b at both ends of the blade 71 on the inner peripheral side of the impeller 7 a. Further, as shown in FIG. 5, each blade 71 is formed with an outer peripheral edge (blade trailing edge) 712 between the portions 71a and 72b at both ends of the blade 71 on the outer peripheral side of the impeller 7a.

  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. .

  Next, specific shapes of the inner peripheral edge 711 and the outer peripheral edge 712 of each blade 71 will be described with reference to the meridional views of FIGS. 7 and 8. 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 an IX-IX sectional view of FIG. 8, and FIG. 10 is an XX sectional view of FIG. The IX-IX cross section is a cross section obtained by cutting a portion of the blade 71 on the main plate 73 side in a direction orthogonal 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. The angle is uniform (for example, an angle of 55 ° to 76 °) over the entire region from the side to the main plate 73 side.

  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 described in the section “Problems to be Solved by the Invention”, the entrance angles αm and αs of the inner peripheral edge portion 711 of each blade 71 are only made uniform over the entire region from the side plate 72 side to the main plate 73 side. Then, it is difficult to sufficiently suppress the separation of the air flow on the side plate 130 side.

  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. It is made into the shape which leaves | separates from the axis line Z of the rotating shaft 70 toward the side plate 72 side from the 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 73a side. It is a ratio (D2 / d2) of the outer peripheral diameter D2 to d2.

  Next, the operation of the air conditioner 1 of the present 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 side plate 72 side toward the main plate 73 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 blower, separation of the air flow on the side plate 130 side can be suppressed, and the air flowing from the rotation axis direction can easily flow to the space between the blades near the suction port 74.

  Further, in the blower 7 of the present embodiment, the outer peripheral edge 712 of the blade 71 is shaped to be away 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.

  Explaining 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.

  In addition, 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 alleviated. 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.

  In particular, 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. 12, the impeller 7a of this embodiment has a smaller outer diameter of the main plate 73 than the first embodiment. . Specifically, in the present embodiment, as shown in FIG. 13, when the impeller 7 a is viewed from the rotation axis direction, the main plate 73 and the main plate 73 and the advancing portion 711 a in the inner peripheral edge 711 do not overlap. The outer diameter of the is reduced.

  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.

  About another structure, it is the same as that of 1st 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.

  About another structure, it is the same as that of 1st Embodiment, According to the air blower 7 of this embodiment, there exists an effect similar to the effect of 1st Embodiment.

  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 lengths along the outer peripheral edge 712 of the blade 71 are equal, and a dividing point Yin 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.

  And when counting in order from the one end side of the rotating shaft direction of the blade | wing 71 among the inner peripheral side dividing point Yin and the outer peripheral side dividing point Yon, the line (the 1st-6th) which connected the same dividing points. The dividing lines Yd1 to Yd6) are set as virtual streamlines.

  About another structure, it is the same as that of 1st Embodiment, According to the air blower 7 of this embodiment, there exists an effect similar to 1st 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).

(Other embodiments)
The embodiment of the present invention has been described above, but the present invention is not limited to this, 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 in which the position of the inner peripheral edge part 711 is located ahead of the rotation direction R of the impeller 7a 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. .

  Moreover, although each above-mentioned embodiment demonstrated the example connected so that the side plate 72 might cover the outer periphery 712 of each blade | wing 71 from the radial direction outer side of the rotating shaft 70, it is not limited to this. For example, as shown in FIG. 18, the side plate 72 may be connected to a portion 71 a existing in the rotation axis direction on one end side of each blade 71 in the rotation axis direction.

  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 to other air conditioners as well as the vehicle.

  (7) The above-described embodiments are not irrelevant to each other, and can be appropriately combined 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.

7a Impeller 7b Scroll casing (casing)
70 Rotating shaft 71 Blade 711 Inner peripheral edge 712 Outer peripheral edge 72 Side plate 73 Main plate 74 Suction port

Claims (8)

An impeller (7a) that rotates about the rotation shaft (70), and a casing (7b) that houses the impeller, and at least air sucked from an intake port (74) that opens at one end side in the rotation shaft direction. In the centrifugal multiblade blower that blows out radially outward of the rotating shaft,
The impeller (7a)
A main plate (73) coupled to the rotating shaft;
A plurality of blades (71) disposed around the axis of the rotating shaft and connected to the main plate at the other end in the rotating shaft direction;
A side plate (72) for connecting the plurality of blades at one end side in the rotational axis direction of the plurality of blades;
The plurality of blades has an inlet angle on each cross section intersecting in a predetermined direction with respect to the inner peripheral edge portion (711) of the blades on the meridian surface of the impeller across the entire range from the side plate side to the main plate side. And the outer peripheral edge (712) of the blade is configured to be separated from the axis of the rotating shaft from the main plate side toward the side plate side. Wing blower.   In the plurality of blades, a portion (711a) on one end side in the rotation axis direction in the inner peripheral edge portion is more than a portion (711b) on the other end side in the rotation axis direction in the inner peripheral edge portion. The centrifugal multiblade fan according to claim 1, wherein the centrifugal multiblade fan is located in front of the rotation direction (R).   The main plate is connected to the other end side in the rotation axis direction of the plurality of blades so as not to overlap with a portion on one end side in the rotation axis direction in the inner peripheral edge in the rotation axis direction. The centrifugal multiblade fan according to claim 2, wherein   The said side plate is connected with the site | part (712) which exists in the radial direction outer side of the said rotating shaft in the one end side of the said rotating shaft direction in these blades of any one of Claim 1 thru | or 3 characterized by the above-mentioned. Centrifugal multiblade blower described in 1.   The said side plate is connected with the site | part (71b) which exists in the said rotating shaft direction in the one end side of the said rotating shaft direction in these several blades, The Claim 1 thru | or 3 characterized by the above-mentioned. Centrifugal multi-blade blower.   6. The plurality of blades, wherein an entrance angle in each cross section orthogonal to the rotation axis direction is uniform over the entire area from the side plate side to the main plate side. The centrifugal multiblade fan according to any one of the above. 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) is divided into the predetermined number so that the length along the peripheral edge is equal. At the time, when the dividing point in the inner peripheral edge and the dividing point in the outer peripheral edge, the line connecting the same first dividing points is a virtual streamline,
The entrance angle in each cross section on the virtual streamline of the plurality of blades is uniform over the entire region from the side plate side to the main plate side. Centrifugal multiblade blower described in 1. When the ratio of the outer peripheral diameter to the inner peripheral diameter on the side plate side of the impeller is the side plate side inner / outer diameter ratio, and the ratio of the outer peripheral diameter to the inner peripheral diameter on the main plate side of the impeller is the main plate side inner / outer diameter ratio,
The centrifugal multiblade fan according to any one of claims 1 to 7, wherein the impeller has an inner / outer diameter ratio of the side plate larger than an inner / outer diameter ratio of the main plate.

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