JP2017172545A - Centrifugal air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve air blowing efficiency by preventing a backflow of air in a centrifugal air blower.SOLUTION: In a centrifugal air blower 10, a housing 20 capable of holding a driving source 12 is provided in a lower part of a casing 18 having a fan 14 accommodated therein, and part of the housing 20 is inserted into the casing 18 so as to constitute an inner peripheral wall of a passage portion 16. A flange 44 protruding to the passage portion 16 side prevents air in the vicinity of a winding end C2 from flowing back to the fan 14 side. An outer peripheral edge portion 40b of a cap portion 40 of the housing 20 abuts on a lower wall portion 36b of the passage portion 16 to come into surface contact with the lower wall portion, so as to improve sealability.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a centrifugal blower, and more particularly to a centrifugal blower used in an air conditioner mounted on a vehicle.

  2. Description of the Related Art Conventionally, a vehicular air conditioner employs a centrifugal blower that includes a fan that takes in inside air or outside air, a motor that rotates the fan, and a casing that surrounds the fan.

  In such a centrifugal blower, for example, as disclosed in Patent Document 1, a spiral air passage in which a passage cross-sectional area gradually increases toward the downstream side is formed inside the casing in a spiral shape, A fan and a motor are provided at a position that becomes the center of the spiral air passage. Then, air is taken into the interior through the air intake opening opened in the casing under the rotational action of the fan, and the air flows to the spiral air passage formed so as to swivel around the outer periphery of the fan, and is sent from the end. The

Japanese Patent No. 3843941

  However, in the centrifugal blower described above, the air that flows along the spiral air passage of the casing may flow backward to the fan side in the vicinity of the outlet of the spiral air passage, leading to a reduction in air blowing efficiency by the fan. Become.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a centrifugal blower capable of improving the blowing efficiency by preventing the backflow of air.

In order to achieve the above-mentioned object, the present invention has a casing and a fan that is housed inside the casing and blows air sucked in the axial direction in the radial direction, and is opened on one end side in the axial direction of the casing. In a centrifugal blower having an air intake port, a spiral passage formed on the outer peripheral side of the fan, and a discharge portion that opens to a winding end side end of the passage,
At the other end in the axial direction of the casing, a housing for holding a drive source for driving the fan is provided, and a part of the housing is inserted to a position facing the passage to form a part of the passage. A flange that protrudes radially outward from the outer peripheral surface of the housing is provided.

  According to the present invention, in the casing constituting the centrifugal blower, a spiral passage is formed on the outer peripheral side of the fan, and the other axial end opposite to the air intake opening at one axial end. Is provided with a housing for holding a drive source for driving the fan. A part of this housing is inserted into the casing and arranged at a position facing the passage, so that a part of the passage is formed, and a flange protruding radially outward from the outer peripheral surface of the housing near the end of winding of the passage Prepare.

  This ensures that the air that flows to the vicinity of the winding end is prevented from flowing back to the fan side by the flange protruding from the outer peripheral surface of the housing in the vicinity of the winding end of the passage. An increase in operating resistance is avoided, and accordingly, the fan can be operated smoothly to improve the blowing efficiency.

  According to the present invention, the following effects can be obtained.

  That is, a housing for holding a drive source for driving the fan is provided at the other axial end of the casing constituting the centrifugal blower, and a part of the passage is formed by inserting a part of the housing into the casing. A flange that protrudes radially outward from the outer peripheral surface of the housing is provided near the end of winding of the passage. As a result, the air that has flowed to the vicinity of the winding end of the passage is reliably prevented from flowing back to the fan side by the flange. Therefore, it is possible to improve the blowing efficiency by smoothly operating the fan. Become.

1 is an overall cross-sectional view of a centrifugal blower according to an embodiment of the present invention.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments of a centrifugal blower according to the present invention will be given and described in detail below with reference to the accompanying drawings. In FIG. 1, reference numeral 10 indicates a centrifugal blower according to an embodiment of the present invention.

  As shown in FIG. 1, the centrifugal blower 10 includes a drive source 12 composed of a motor and the like, a fan 14 rotating under the drive action of the drive source 12, and the fan 14 and a spiral passage. A casing 18 having a portion 16 and a housing 20 provided at a lower portion of the casing 18 and holding the drive source 12 are included.

  The drive source 12 is provided, for example, at a substantially central lower portion of the casing 18, and the rotating shaft 22 projects into the casing 18 and is connected to the fan 14.

  The fan 14 is housed in the approximate center of the casing 18 and has a plurality of blades 24 spaced apart at equal intervals along the circumferential direction, an annular shroud 26 provided at the upper end portion of the blade 24, and a lower end portion of the blade 24. The center of the boss 28 that is inclined from the center toward the outer peripheral side and downward (in the direction of arrow A) is connected to the rotating shaft 22 of the drive source 12.

  As a result, the air taken in from the shroud 26 due to the rotation of the fan 14 is guided downward (in the direction of arrow A) along the boss portion 28 toward the outer peripheral side, and then the outer peripheral side through each blade 24. Is sent to.

  The casing 18 includes, for example, a case main body 30 in which the fan 14 is accommodated in a substantially central portion and can be divided in the axial direction (the directions of the arrows A and B). An air intake 32 is open at the center of the upper end along the direction (the direction of arrows A and B). For example, the air intake 32 is opened in a substantially circular shape, and the inside and the outside of the casing 18 are communicated with each other, and a bell mouth 34 that is folded back inward is formed on the outer peripheral portion.

  The passage portion 16 formed inside the case body 30 is formed, for example, in a rectangular cross section, and the outer peripheral wall 16a has a diameter so as to gradually move away from the case body 30 from the winding start C1 toward the winding end C2. A logarithmic spiral is formed outward in the direction. Further, the passage portion 16 is formed such that the position of the upper wall portion 36a does not change from the winding start C1 to the winding end C2, and the lower wall portion 36b is gradually inclined downward (in the direction of arrow A). As a result, the passage cross-sectional area gradually increases toward the end of winding C2.

  A discharge portion (not shown) that extends linearly from the winding end C2 toward the tangential direction and has an open end is formed at the winding end C2 of the passage portion 16.

  The housing 20 includes, for example, a holder portion 38 formed in a cylindrical shape with a bottom from a resin material, and a cap portion 40 provided on the radially outer side of the holder portion 38, and the holder portion 38 is a drive source 12. The drive source 12 is housed in the same axis as the fan 14, and a part of the drive source 12 is housed in the case body 30.

  The holder portion 38 is formed in a cylindrical shape and accommodates the drive source 12 therein, a flange 44 extending radially outward from the upper end portion of the storage portion 42, and the storage portion 42. And a wall 48 extending vertically downward (in the direction of arrow A) with respect to the flange 44.

  For example, the flange 44 is formed along the circumferential direction of the holder portion 38, and when the housing 20 including the holder portion 38 is attached to the lower portion of the casing 18, the winding start C1 to the winding end C2 of the passage portion 16 in the casing 18 are performed. And abut against the lower wall portion 36b. At this time, surface contact is made in which the flange 44 and the lower wall portion 36b of the passage portion 16 are in contact with each other with a predetermined area.

  Further, the flange 44 is formed so as to protrude by a predetermined length toward the passage portion 16 in the vicinity of the winding end C <b> 2 of the case body 30 and to be substantially orthogonal to the outer peripheral wall 16 a of the casing 18. Furthermore, the flange 44 is formed in a size that can be inserted into the opening of the lower wall portion 36b when the holder portion 38 is assembled to the casing 18 from below to above (in the direction of arrow B).

  A wall portion 48 is provided at a position that is a predetermined distance from the outer peripheral end of the flange 44 toward the storage portion 42 side.

  The wall portion 48 functions as an inner peripheral wall of the passage portion 16 by housing the holder portion 38 in the case main body 30, and a cooling hole is provided near the lower end of the wall portion 48 so as to face the vicinity of the winding end C <b> 2 of the case main body 30. 50 is opened and communicates with a cooling passage 52 formed between the wall portion 48 and the storage portion 42. The cooling passage 52 allows the cooling hole 50 to communicate with the holder hole 42 a opened on the side surface of the storage portion 42.

  The cap portion 40 is provided so as to cover a lower portion of the holder portion 38 and a part of the casing 18, and an inner peripheral edge portion 40 a formed in a flat shape abuts against a bottom portion of the storage portion 42 in the holder portion 38, while The outer peripheral edge portion 40b formed in a shape contacts the lower side of the lower wall portion 36b near the winding end C2 in the casing 18.

  That is, the cap portion 40 is in a surface contact state in which the inner peripheral edge portion 40a is in contact with the lower portion of the holder portion 38 with a predetermined area, and the outer peripheral edge portion 40b is similarly in a predetermined area with respect to the lower wall portion 36b of the casing 18. It will be in the surface contact state contacted by.

  A part of the air flowing through the passage portion 16 flows into the cooling passage 52 surrounded by the cap portion 40 through the cooling hole 50 in the vicinity of the winding end C2, and is introduced into the holder portion 38 through the holder hole 42a. Thus, the drive source 12 is cooled.

  The centrifugal blower 10 according to the embodiment of the present invention is basically configured as described above. Next, its operation and effects will be described.

  First, the fan 14 rotates under the driving action of the drive source 12 based on a control signal from a controller (not shown), so that air is sucked into the fan 14 from the air intake port 32 opened above the casing 18. It is. Then, the air taken into the inside of the fan 14 is guided downward and to the outer peripheral side along the boss portion 28, then passes between the plurality of blades 24 and is sent to the passage portion 16 on the outer peripheral side. The

  The air sent to the passage portion 16 flows along the passage portion 16 from the start of winding C1 to the end of winding C2, reaches the end of winding C2, and then flows out to the outside through a discharge portion (not shown). Is done. At this time, a flange 44 is provided near the winding end C2 of the passage portion 16 so as to protrude from the housing 20 provided on the inner peripheral side toward the passage portion 16 side. It is possible to prevent the air flowing along the lower wall portion 36b from flowing backward to the fan 14 side arranged on the upper side and the inner peripheral side.

  That is, the flange 44 is provided at a position between the lower wall portion 36 b of the passage portion 16 and the fan 14 in the vicinity of the winding end C <b> 2 of the passage portion 16.

  In addition, since the outer peripheral edge portion 40b of the cap portion 40 is provided on the lower wall portion 36b of the passage portion 16 so as to overlap with each other, the air leaks from the connection portion between the casing 18 and the housing 20 to the outside. There is no end.

  Further, a part of the air is taken into the housing 20 through the cooling hole 50 opened in the vicinity of the winding end C2 of the passage portion 16, flows along the cooling passage 52, and is supplied into the holder portion 38. As a result, the drive source 12 housed in the holder portion 38 is suitably cooled.

  As described above, in the present embodiment, the housing 20 that can hold the drive source 12 is provided in the lower portion of the casing 18, and a part of the housing 20 is inserted into the casing 18, whereby the wall portion 48 of the housing 20 is formed. By constituting the inner peripheral wall of the passage portion 16 and providing the flange 44 so as to protrude radially outward from the wall portion 48, the air that has flowed along the passage portion 16 to the vicinity of the end of winding C <b> 2 is caused by the flange 44. Backflow to the side is prevented. As a result, an increase in the operating resistance of the fan 14 due to the backflow of air can be avoided, and accordingly, the fan 14 can be operated smoothly to improve the blowing efficiency.

  Further, by forming an outer peripheral edge portion 40 b extending outward in the radial direction in the cap portion 40 constituting the housing 20, the outer peripheral edge portion 40 b is brought into surface contact with the lower wall portion 36 b of the passage portion 16 in the case body 30. The air leakage between the housing 20 and the casing 18 is surely prevented, and the sealing performance can be improved.

  Furthermore, in the housing 20, a cooling hole 50 is formed at a position near the winding end C <b> 2 of the passage portion 16 so as to open to the wall portion 48 of the holder portion 38. There is no need to provide a cooling chamber, and the drive source 12 can be reliably cooled. Therefore, compared with the case where the cooling chamber for cooling the drive source 12 is provided separately, the centrifugal blower 10 can be reduced in size and weight.

  In addition, the centrifugal blower according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Centrifugal blower 12 ... Drive source 14 ... Fan 16 ... Passage part 18 ... Casing 20 ... Housing 30 ... Case main body 38 ... Holder part 40 ... Cap part 44 ... Flange 48 ... Wall part 50 ... Cooling hole 52 ... Cooling passage

Claims (1)

A casing, and a fan that blows air sucked in an axial direction stored in the casing in a radial direction, the casing having an air intake opening that opens on one end side in the axial direction, and an outer peripheral side of the fan In a centrifugal blower having a spiral passage formed and a discharge portion opening at an end portion on the winding end side of the passage,
A housing for holding a drive source for driving the fan is provided at the other axial end of the casing, and a part of the housing is inserted to a position facing the passage to form a part of the passage. A centrifugal blower comprising a flange projecting radially outward from the outer peripheral surface of the housing near the end of winding of the passage.

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