JP2014181679A - Air conditioner for vehicles - Google Patents

Abstract

In a vehicle air conditioner, the fan efficiency of a centrifugal fan provided with a sirocco fan is greatly improved.
A plurality of recesses 15 whose inner wall surface is a smooth surface without a bent portion are provided on the pressure surface 13 side of a blade 9b2 having a blade shape in cross section.
[Selection] Figure 3

Description

  The present invention relates to a vehicle air conditioner.

  Generally, a vehicle air conditioner is mounted on the front side in a vehicle, and is configured to dehumidify and cool air blown by a blower using an evaporator. When the vehicle air conditioner is an air mix system, part or all of the air that has passed through the evaporator is sent to the heater core via the air mix door and heated, and then mixed with the remaining air to reach a predetermined temperature. The conditioned air is generated, and the generated conditioned air is supplied to each outlet in the vehicle.

  As a blower installed in such a vehicle air conditioner, a centrifugal blower including a sirocco fan is used. The sirocco fan has a configuration in which a large number of blades are arranged in an annular shape around a shaft portion, and blows air radially outward by applying rotational power to the shaft portion from a motor.

  Patent Document 1 discloses a blower in which the cross-sectional shape of a blade of a sirocco fan is a wing shape. According to this patent document 1, since the blade has a blade shape in cross section, the flow on the surface of the blade becomes smooth, the negative pressure region formed around the blade is reduced, and fan efficiency can be improved. .

  Patent Document 2 discloses a blower having a shape in which a cross-sectional shape of a blade of a sirocco fan is bent a plurality of times. This Patent Document 2 is intended to improve fan efficiency by forming a vortex flow in a recess formed by bending, thereby smoothing the flow around the blade.

Japanese Patent Publication No.33-5589 JP 2011-58413 A

  However, when a simulation was performed using a model simulating the blade shape disclosed in Patent Document 1 and Patent Document 2, the blade shape disclosed in Patent Document 1 increases the weight due to the blade becoming thick. As a result, the required rotational power increased, resulting in a slight improvement in fan efficiency. In the blade shape disclosed in Patent Document 2, the negative pressure region around the blade has increased.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to greatly improve the fan efficiency of a centrifugal blower including a sirocco fan in a vehicle air conditioner.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention is a vehicle air conditioner provided with the blower unit which has the case where an air flow path is formed in an inside, and the sirocco fan arrange | positioned inside the said case, Comprising: The said sirocco fan is a shaft. And a plurality of blades arranged annularly around the shaft portion, and the cross-sectional shape of the blade is such that the leading edge is radially inward of the sirocco fan and the trailing edge is radially outward of the sirocco fan The blade is configured such that a pressure surface arranged and curved so as to be depressed is directed forward in the rotational direction of the sirocco fan, and a suction surface curved so as to be expanded is directed rearward in the rotational direction of the sirocco fan, On the positive pressure surface side, a configuration is adopted in which a plurality of recesses whose inner wall surface is a smooth surface without a bent portion are provided.

  In a second aspect based on the first aspect, the plurality of recesses are arranged from the front edge toward the rear edge, and the cross-sectional area of the recess is from the front edge to the center in the arrangement direction of the recesses. A configuration is adopted that increases toward the rear edge and then decreases toward the trailing edge.

  According to a third aspect of the present invention, in the second aspect of the present invention, the distance from the bottom of each recess to the suction surface is constant.

  According to a fourth invention, in any one of the first to third inventions, a configuration is adopted in which each recess is provided in a groove shape extending in the axial direction of the sirocco fan.

  According to the present invention, since the cross-sectional shape of the blade is a wing shape, the flow on the surface of the blade is smooth, and the negative pressure region can be reduced as compared with a curved plate-like blade. Furthermore, since a plurality of recesses are provided on the pressure surface side, the weight of the blade can be reduced. In addition, since the inner wall surface of the concave portion is a smooth surface without a bent portion, a large single vortex is easily formed in the concave portion, and the viscous resistance on the pressure surface side can be reduced. According to the present invention as described above, the fan efficiency of the centrifugal blower including the sirocco fan can be greatly improved in the vehicle air conditioner.

It is sectional drawing which shows schematic structure of the air conditioning apparatus for vehicles in one Embodiment of this invention. It is a perspective view of the sirocco fan with which the air harmony device for vehicles in one embodiment of the present invention is provided. (A) is sectional drawing of the blade of the sirocco fan with which the air conditioning apparatus for vehicles in one Embodiment of this invention is provided, (b) is a front view. It is a graph for demonstrating fan efficiency about the air conditioning apparatus for vehicles in one Embodiment of this invention.

  Hereinafter, an embodiment of a vehicle air conditioner according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a vehicle air conditioner S of the present embodiment. The vehicle air conditioner S includes a blower unit Sa, a cooler unit (not shown), a heater unit (not shown), and the like. FIG. 1 is a cross-sectional view of the blower unit Sa. The vehicle air conditioner S of the present embodiment is characterized by the blower unit Sa. Therefore, the following description is mainly for the blower unit Sa.

  The blower unit Sa is provided such that the outside air inlet 4 described later is on the upper side when the vehicle air conditioner S is mounted inside the instrument panel in the front part of the vehicle interior. That is, the blower unit Sa is provided in the upright state shown in FIG.

  The blower unit Sa includes an inside / outside air switching device 1. The inside / outside air switching device 1 includes a case 2 having a space of a predetermined capacity inside. The case 2 is provided with an inside air introduction port 3, an outside air introduction port 4, a semi-inside air introduction port 5, and a discharge port 6.

  The inside air introduction port 3 is provided so as to open a part of the side surface of the case 2, the outside air introduction port 4 is provided so as to open a part of the upper surface of the case 2, and the half inside air introduction port 5 A part of the side surface of the case 2 facing the introduction port 3 is provided so as to open, and the discharge port 6 is provided so as to open a part of the bottom surface of the case 2. The semi-inside air introduction port 5 is provided with a flexible semi-inside air door 10, and is an opening for taking a part of the inside air into the case 2 when taking outside air into the case 2.

  Inside the case 2, an inside / outside air switching door 7 and a filter 8 are provided. Among these, the inside / outside air switching door 7 is composed of a rotary door, and is configured to be rotatable by a driving mechanism (not shown) around the rotation shaft 7a.

  The inside / outside air switching door 7 is rotated to open the inside air introduction port 3 and close the outside air introduction port 4, and to close the inside air introduction port 3 and open the outside air introduction port 4. To be. As shown in FIG. 1, when the outside air inlet 4 is turned to a closed state, the inside air is taken into the case 2 from the inside air inlet 3 (see arrow (x1)), and the inside / outside air switching door 7 When the inside air introduction port 3 is turned to a closed state, the outside air can be taken into the case 2 from the outside air introduction port 4 (see arrow (x2)). The inside / outside air switching door 7 may be a plate-type door as long as the inside air introduction port 3 and the outside air introduction port 4 can be alternatively selected as described above.

  The filter 8 is an air filter having a function of removing dust contained in the air taken into the case 2, and is provided so as to close the discharge port 6. Therefore, clear air filtered by the filter 8 can be supplied to a conditioned air generation unit (cooler unit and heater unit) (not shown) that includes the evaporator of the vehicle air conditioner S and the like.

  The blower unit Sa includes a centrifugal blower 9. The centrifugal blower 9 is disposed below the inside / outside air switching device 1. The centrifugal blower 9 is connected to the case 2 of the inside / outside air switching device 1 and has a hollow case 9a having a predetermined opening, a sirocco fan 9b installed in the case 9a, and the sirocco fan 9b. And a driving motor 9c.

  The case 9a is a hollow container having an air flow path formed therein, and has a central portion 9a1 that houses the sirocco fan 9b, and a scroll flow passage 9a2 that is wound around the central portion 9a1. Yes. The case 9a has an opening provided at the downstream end of the scroll channel 9a2 connected to the conditioned air generation unit.

  FIG. 2 is a perspective view of the sirocco fan 9b. As shown in this figure, the sirocco fan 9b is composed of a shaft portion 9b1 and a plurality of blades 9b2. The shaft portion 9b1 is connected to the motor 9c with the axial direction facing up and down, and rotates around the axial direction by receiving rotational power from the motor 9c. In the present embodiment, the shaft portion 9b1 is rotated in the rotation direction (that is, clockwise) shown in FIG. Each of the blades 9b2 is fixed to the shaft portion 9b1, and is arranged in an annular shape around the shaft portion 9b1. Note that FIG. 2 is a diagram for explaining the entire sirocco fan 9b, and therefore, the description of the concave portion 15 described later is omitted to improve the visibility. Similarly, in FIG. 1, the description of a concave portion 15 described later is omitted.

  FIG. 3A is a cross-sectional view taken along a plane orthogonal to the axial direction of the shaft portion 9b1 of the blade 9b2. As shown in this figure, the cross-sectional shape of the blade 9b2 is such that the front edge 11 is disposed radially inward of the sirocco fan 9b and the rear edge 12 is disposed radially outward of the sirocco fan 9b. A suction surface 14 that is directed forward in the rotational direction and curved so as to swell is formed into a wing shape that is directed rearward in the rotational direction.

  As shown in FIG. 3A, a plurality of recesses 15 whose inner wall surface is a smooth U-shaped surface without a bent portion are provided on the pressure surface 13 side of the blade 9b2. These recesses 15 are arranged from the front edge 11 toward the rear edge 12. In addition, the cross-sectional area of each recess 15 gradually increases from the front edge 11 toward the center of the recess 15 in the arrangement direction (the part where the blade-shaped blade 9b2 is thickest), and then the rear edge 12 from the center in the arrangement direction. It is set so that it gradually becomes smaller toward. Thus, the distance from the bottom 15a of each recess 15 to the suction surface 14 is constant. FIG. 3B is a front view of the blade 9b2 as seen from the positive pressure surface 13 side. As shown in this figure, each recess 15 extends over the entire area in the height direction of the blade 9b2 (the vertical direction shown in FIG. 2).

  Returning to FIG. 1, the motor 9c is disposed below the sirocco fan 9b, and its output end is connected to the shaft 9b1 of the sirocco fan 9b. The motor 9c generates rotational power when supplied with electric power, and rotates the sirocco fan 9b.

  In the vehicle air conditioner S including the blower unit Sa configured as described above, when the sirocco fan 9b is rotationally driven by the motor 9c, the inside air or the outside air is changed according to the attitude of the inside / outside air switching door 7. 1 and air is supplied to the centrifugal blower 9 through the filter 8. The air supplied to the centrifugal blower 9 flows in the case 9a and flows upward into the sirocco fan 9b, is accelerated in the radial direction and discharged, is discharged from the centrifugal blower 9 through the scroll flow path 9a2, and is conditioned air. Supplied to the generation unit.

  In the vehicle air conditioner S of this embodiment, since the cross-sectional shape of the blade 9b2 is a wing shape, the flow on the surface of the blade 9b2 is smooth, which is negative compared to a curved plate-like blade. The pressure area can be reduced. Further, since the plurality of recesses 15 are provided on the positive pressure surface 13 side, the weight of the blade can be reduced. Further, since the inner wall surface of the recess 15 is a smooth surface without a bent portion, a large single eddy current R (see FIG. 3A) is easily formed in the recess 15, and the pressure surface 13 side is easily formed. Viscous resistance can be reduced. According to the vehicle air conditioner S of this embodiment, the fan efficiency of the centrifugal blower 9 including the sirocco fan 9b can be greatly improved.

  FIG. 4 is a graph comparing the performance of the centrifugal blower 9 of the vehicle air conditioner S of the present embodiment and the centrifugal blower having a sirocco fan with a blade of a conventional shape. In this graph, the conventional shape 1 is a plate-like shape with a curved cross-sectional shape of the blade, the conventional shape 2 is a blade-shaped cross-sectional shape (approximate shape of Patent Document 1), and the conventional shape 3 is The cross-sectional shape of the blade is a shape bent at a plurality of locations (approximate shape of Patent Document 2). Moreover, this graph is the result obtained by the fluid analysis by the same conditions using the model of the said shape containing this embodiment.

  In the simulation using the conventional shape 1, a large separation vortex was formed on the suction surface side of the blade, and as a result, a large negative pressure region was formed on the suction surface side.

  In the simulation using the conventional shape 2, although the blade weight was increased as compared with the conventional shape 1, the separation vortex formed on the suction surface side of the blade was small, and the negative pressure region on the suction surface side was small. As a result, as shown in FIG. 4, the fan efficiency was slightly improved.

  In the simulation using the conventional shape 3, it was confirmed that a larger negative pressure region was formed on the suction surface side of the blade than the conventional shape 1. In the simulation using the conventional shape 3, as shown in FIG. 4, the fan efficiency is improved compared to the conventional shape 1, but not as much as the simulation using the blade shape of the present embodiment.

  In the simulation using the blade shape of the present embodiment, the negative pressure region on the suction surface side of the blade decreased as in the conventional shape 2. Furthermore, weight reduction is achieved compared with the conventional shape 2. For this reason, as shown in FIG. 4, the fan efficiency is dramatically improved as compared with the conventional shape 1, the conventional shape 2, and the conventional shape 3.

  From such simulation, it was confirmed that the vehicle air conditioner S of the present embodiment can greatly improve the fan efficiency as compared with the vehicle air conditioner including the blade-shaped sirocco fan of the conventional shape.

  Further, in the vehicle air conditioner S of the present embodiment, the plurality of recesses 15 are arranged from the front edge 11 toward the rear edge 12, and the cross-sectional area of the recess 15 is the arrangement of the recesses 15 from the front edge 11. It becomes larger toward the center in the direction and then smaller toward the rear edge 12. Further, the distance from the bottom of each recess 15 to the suction surface 14 is constant. According to the vehicle air conditioner S of this embodiment, each recess 15 can be maximized while maintaining the strength and aerodynamic performance of the blade 9b2. For this reason, it is possible to reduce the weight of the blade 9b2 and to greatly improve the fan efficiency.

  Further, in the vehicle air conditioner S of the present embodiment, each recess 15 is provided in a groove shape extending in the entire area of the blade 9b2 in the axial direction of the sirocco fan 9b. For this reason, even if the air passes through any position in the height direction of the blade 9b2, the flow becomes smooth by the vortex flow R formed inside the recess 15, and the negative pressure region is reduced.

  Further, in the vehicle air conditioner S of the present embodiment, since the extending direction of the recess 15 is the same as the extending direction of the hole of the shaft portion 9b1, the sirocco fan 9b is separated from the shroud 9b3 (see FIG. 2). In addition, it is possible to mold with a mold having a radially inner side as an upper mold and a radially outer side as a lower mold, and can be easily manufactured without using a complicated mold.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Inside / outside air switching device, 2 ... Case, 3 ... Inside air introduction port, 4 ... Outside air introduction port, 5 ... Semi inside air introduction port, 6 ... Discharge port, 7 ... Inside / outside air switching door, 7a ...... Rotating shaft, 8... Filter, 9... Centrifugal blower, 9 a .. Case, 9 a 1. Blade: 9c: Motor, 10: Semi-inside door, 11: Front edge, 12: Rear edge, 13: Pressure surface, 14: Pressure surface, 15: Recess, 15a: Bottom, R ... ... Swirl, S ... Vehicle air conditioner, Sa ... Blower unit

Claims (4)

A vehicle air conditioner comprising a case in which an air flow path is formed inside and a blower unit having a sirocco fan arranged inside the case,
The sirocco fan has a shaft portion and a plurality of blades arranged in a ring around the shaft portion,
The cross-sectional shape of the blade is such that a leading edge is disposed radially inside the sirocco fan and a trailing edge is disposed radially outside the sirocco fan, and a positive pressure surface curved so as to be recessed is directed forward in the rotational direction of the sirocco fan. , The suction surface curved so as to swell is a wing shape directed rearward in the rotational direction of the sirocco fan,
A plurality of concave portions whose inner wall surface is a smooth surface without a bent portion are provided on the positive pressure surface side of the blade. The plurality of recesses are arranged from the front edge toward the rear edge;
2. The vehicle air conditioner according to claim 1, wherein a cross-sectional area of the concave portion increases from the front edge toward the center of the concave portion in the arrangement direction and then decreases toward the rear edge.   The vehicle air conditioner according to claim 2, wherein the distance from the bottom of each recess to the suction surface is constant.   4. The vehicle air conditioner according to claim 1, wherein each recess is provided in a groove shape extending in an axial direction of the sirocco fan.

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