JP2018155188A - Centrifugal fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal fan capable of securing rigidity while reducing the weight.SOLUTION: A centrifugal fan 100 includes an upper casing 101 made of resin, a lower casing 102 made of resin, and an impeller 103 disposed between the upper casing 101 and the lower casing 102 in such a manner of being rotatable. A recession 111 is formed in the lower casing 102. A hollow cylindrical bearing holder 124 formed as a part of the lower casing 102 and vertically arranged in an axial direction so as to rotatably hold a rotating shaft member of the impeller 103, and ribs 125, 126 radially and concentrically formed are formed in the recession 111.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a centrifugal fan.

  Centrifugal fans are known as blowers that are widely used for cooling, ventilation, air conditioning, vehicle air conditioning, air blowing, and the like for home appliances, OA equipment, and industrial equipment. As a conventional centrifugal fan, the casing consists of an upper casing and a lower casing. An impeller is accommodated between the upper casing and the lower casing, and the air sucked from the suction port as the impeller rotates is placed between the upper casing and the lower casing. There is known a structure that discharges outward from a blow-out port formed on the side surface (see, for example, Patent Document 1).

  FIG. 8 shows a centrifugal fan 1 described in Patent Document 1. In the structure of FIG. 8, the air sucked from the suction port 33 passes between the blades 51 of the impeller 30, is blown out toward the outside of the impeller 30, and is blown out to the side of the impeller 30. It is discharged from the mouth 19. The casing is configured by assembling a resin upper casing 11 and a metal lower casing 21 to each other using screws 14 located at four corners in plan view. The upper casing 11 and the lower casing 21 are assembled to each other so as to sandwich the column at the portion where the screw 14 is disposed. The outlet 19 is provided in a portion excluding a fastening portion between the upper casing 11 and the lower casing 21 using the screw 14. A connector 71 for supplying power to the motor 60 is attached to the lower casing 21.

  However, in the centrifugal fan 1 described in Patent Document 1, since the lower casing 21 functions as the main plate of the impeller 30, the accuracy of the gap formed between the lower surface of the blade 51 and the lower casing 21 is important. It is necessary to make the flatness of the lower casing 21 highly accurate. For this reason, the processing cost of components cannot be reduced. Moreover, since the lower casing 21 is formed of a metal plate, there is a problem that this is obstructed with respect to the demand for weight reduction of the centrifugal fan.

  On the other hand, the fan motor shown in FIG. 9 includes a housing 12 whose case is formed in a scroll shape and a yoke 14 that supports the motor for rotating the rotary fan 22. It is integrally formed in the yoke 14 by insert molding, and the connector part 42 is also provided integrally with the yoke 14 (for example, refer patent document 2).

  Although the material of the yoke 14 in the fan motor described in Patent Document 2 is not clear, the insert iron plate is integrally formed in the yoke 14 by insert molding, and the connector portion is also provided integrally with the yoke 14. Therefore, it can be inferred that the yoke 14 is formed by resin molding.

JP 2014-167304 A Japanese Patent Laid-Open No. 11-294837

  When the yoke 14 in the fan motor described in Patent Document 2 is formed by resin molding, the thickness of the yoke 14 cannot be reduced, and when the thickness of the yoke 14 is reduced, the rigidity of the yoke 14 ( Strength) decreases, and the natural frequency of the member decreases, causing vibration. For this reason, it cannot fully respond to the demand for lighter fans.

  In such a background, an object of the present invention is to obtain a centrifugal fan that is lightweight while ensuring rigidity.

  The present invention is a centrifugal fan comprising a resin upper casing, a resin lower casing, and an impeller disposed in a rotatable state between the upper casing and the lower casing, the lower casing Is formed as a part of the lower casing, and is a hollow cylindrical bearing holder that is erected in the axial direction to hold the rotating shaft member of the impeller in a rotatable state. And a centrifugal fan in which radial and concentric ribs are formed.

  In the present invention, the radially formed ribs may include an embodiment in which the inner periphery of the recess is connected to the outer periphery of the bearing holder. In the present invention, there may be mentioned an aspect in which a support column extending in the direction of the lower casing is provided on the peripheral edge of the upper casing, and the support column and the lower casing are welded.

  In the present invention, a mode in which the connector to which the lower casing and the wiring from the outside are connected is engaged by the engaging means. In the present invention, an aspect in which a connector to which wiring from the outside is connected is formed as a part of the lower casing. In the present invention, a mode in which a bearing sleeve equipped with a pair of bearings is fitted inside the bearing holder can be mentioned.

  In the present invention, there may be mentioned an aspect in which a rib is provided to connect the outer peripheral surface of the protruding portion protruding from the lower surface of the lower casing and the flat portion extending radially outward from the protruding portion. In the present invention, there is an aspect in which a rib is provided to connect the connector and a flat portion extending radially outward from a protruding portion protruding on the lower surface of the lower casing.

  In the present invention, a fluid outlet is provided on a side surface excluding a support column interposed between the upper casing and the lower casing, and the outlet is configured so that the fluid to be blown is obliquely downward. The aspect which has the shape induced | guided | derived is mentioned.

  An object of the present invention is to obtain a centrifugal fan that is lightweight and secures rigidity.

It is a disassembled perspective view of the centrifugal fan of embodiment. It is the perspective view which looked at the centrifugal fan of the embodiment from the bottom side. It is sectional drawing of embodiment. It is sectional drawing of embodiment. It is sectional drawing of embodiment. It is a perspective view which shows other embodiment of a lower casing. FIG. 7 is a side view of FIG. 6. It is sectional drawing which shows the conventional centrifugal fan (patent document 1). It is a disassembled perspective view which shows the other conventional fan (patent document 2).

(1) 1st Embodiment The basic structure of the centrifugal fan 100 of embodiment is shown by FIG. The centrifugal fan 100 includes a resin upper casing 101, a resin lower casing 102, and an impeller 103 that is rotatably disposed between the upper casing 101 and the lower casing 102. A recess 111 is formed, and the recess 111 is formed in a radial and concentric manner with a hollow cylindrical bearing holder 124 erected in the axial direction for holding the rotating shaft member of the impeller 103 in a rotatable state. Ribs 125 and 126 are integrally formed as a part of the lower casing 102.

  The casing of the centrifugal fan 100 includes an upper casing 101 and a lower casing 102, and an impeller 103 is accommodated between the upper casing 101 and the lower casing 102. A suction port 104 through which fluid, for example air, flows from above is provided at the center of the upper casing 101, and the side of the upper casing 101 excluding the support column 107 interposed between the upper casing 101 and the lower casing 102 has air suction. A blowout port 108 (see FIGS. 2 and 3) is provided. When the impeller 103 rotates, air flows into the suction port 104 from above, and the air flow that has passed between the blades 16 of the impeller 103 is blown outward from the blowout port 108. The air outlet 108 has a shape in which an air flow is blown obliquely downward. Here, the diagonally downward direction is a direction having a radially outer component and an axial component from the upper casing 101 toward the lower casing 102.

  Specifically, as shown in FIG. 3, the inner peripheral surface of the edge 101a portion of the upper casing 101 constituting the outlet 108 is formed into a curved surface or an inclined surface whose inner diameter increases toward the outer side. Has been. Further, the outer peripheral surface of the edge 102a of the lower casing 102 is formed into a curved surface or an inclined surface whose outer diameter increases as it goes in the radially outer direction. With such a structure, the direction of the air outlet 108 is set to be obliquely downward, and the air flow from the air outlet 108 is guided obliquely downward (for example, the direction of 45 ° obliquely downward in FIG. 3). ing. By making the airflow blow out obliquely downward, the recirculation of the airflow from the blowout port 108 to the suction port 104 can be suppressed. In order to more effectively realize the air flow, it is preferable that the edges 101a and 102a have curved surfaces. It should be noted that the edge 101a of the upper casing 101 and the edge 102a of the lower casing 102 may of course have a planar shape that is straight outward. Since the upper casing 101 and the lower casing 102 are made of resin, the edge structure described above can be easily obtained. Moreover, weight reduction of the whole apparatus is achieved by making the upper casing 101 and the lower casing 102 into resin.

  The lower casing 102 has a recess 111, and a motor 110 integrated with the circuit board 112 is mounted on the bottom surface of the recess 111.

  A plurality of ribs 113 are formed concentrically and radially on the upper surface side of the upper casing 101, and concave portions (meat stealing portions) 114 are formed between the ribs 113. The upper casing 101 and the lower casing 102 are joined by interposing a support column 107 between the upper casing 101 and the lower casing 102. Specifically, the support column 107 is formed on a flange portion 115 provided on the outer peripheral portion of the upper casing 101, and is integrally formed with the upper casing 101 by injection molding of a resin (PBT resin, including GF reinforcement of PBT). The protrusion 107 a is formed at the tip of the support column 107. That is, the support column 107 and the flange portion 115 are formed as a part of the upper casing 101. The protrusion 107a is inserted into a through-hole 119 formed in the flange 118 of the lower casing 102, and the protrusion 107a protruding from the through-hole 119 is welded (for example, ultrasonic welding, vibration welding, laser welding, etc.) or heat caulking. By doing so, the support column 107 and the lower casing 102 are joined.

  The impeller 103 includes an annular shroud 121, a main plate 122, and a plurality of blades 106 disposed between the shroud 121 and the main plate 122. All of the blades 106 are rearward blades having the same shape and are equally arranged in the circumferential direction. In this embodiment, the annular shroud 121 and the blade 106 are integrally formed by resin molding, and the main plate 122 is integrally formed by insert molding of a hollow bush 136 made of brass, and then the main plate 122 is ultrasonically welded to the lower surface of the blade 106. And joined.

  (1) A configuration in which the annular shroud 121 and the blade 106 are integrally formed, and then the main plate 122 is integrally formed by resin two-color molding (at this time, the bush is insert-molded), (2) the main plate 122 and the blade A structure in which the shroud 121 is ultrasonically welded and joined to the upper surface of the blade 122 may be employed after the 106 is integrally formed (at this time, the bush is insert-molded), and the structure of the impeller 103 is not particularly limited.

  The inner peripheral edge of the shroud 121 constitutes a suction port 104, and this inner peripheral edge forms an annular protrusion 129 standing in the axial direction. As shown in FIG. 3, the annular protrusion 129 of the shroud 121 is accommodated and covered in an annular recess formed on the lower surface of the upper casing 101 with a minute gap therebetween, thereby functioning as a labyrinth seal. . This prevents a phenomenon in which a part of the air flow blown out from the blowout port 108 flows backward to the suction port 104 through a gap formed between the upper surface of the shroud 121 and the lower surface of the upper casing 101.

  The lower casing 102 has a concave portion 111 and a stepped portion 123 formed on the outer periphery thereof. A hollow cylindrical bearing holder 124 is erected in the axial direction at the center of the concave portion 111. The outer peripheral side of the 103 main plate 122 is accommodated.

  First ribs 125 extending radially from the outer periphery of the hollow cylindrical bearing holder 124 to the outermost periphery of the recess 111 are formed radially on the bottom surface of the recess 111. Six first ribs 125 formed radially are provided at equiangular positions when viewed from the axial direction. The number of the first ribs 125 is not limited to six. In addition, a concentric second rib 126 is provided on the bottom surface of the recess 111 so as to connect the adjacent first ribs 125. A plurality of ribs 126 formed concentrically may be provided. One end (radially outer end) of the radially formed rib 125 is connected to the inner periphery of the recess 111, and the other end (radially inner end) is connected to the outer periphery of the bearing holder 124.

  The lower casing 102, the bearing holder 124, the rib 125 and the rib 126 are formed by integral molding of resin. That is, the bearing holder 124, the rib 125, and the rib 126 are part of the lower casing 102 and are made of the same material.

  As shown in FIG. 3, a ball bearing 127 inserted from above and a ball bearing 128 inserted from a lower hole 139 are fitted on the inner periphery of the bearing holder 124. A cylindrical shaft 135 serving as a rotating shaft member of the impeller 103 is held by the bearing holder 124 in a freely rotatable state by the ball bearings 127 and 128. A donut-shaped bush 136 is fixed to the shaft 135, and the outer periphery of the bush 136 is fixed to the impeller 103. A preload is applied to the ball shaft bearing 127 by the preload spring 138.

  A stator of the motor 110 is disposed on the outer periphery of the bearing holder 124. Specifically, the stator core of the motor 110 is fixed to the bearing holder 124 by fitting the bearing holder 124 into an opening formed in the center of the stator core. A coil is wound around each salient pole (tooth) of the stator core via a resin insulator. A circuit board 112 is bonded to the lower end side of the insulator, and the circuit board 112 is accommodated in the recess 111 of the lower casing 102.

  An opening 137 is formed in a part of the bottom surface of the recess 111 of the lower casing 102, and the connector 130 is attached to the portion of the opening 137 from the lower surface of the lower casing 102. The connector 130 is provided with a concave engaging means 131, and the lower casing 102 is provided with a convex mating engaging means that engages with the engaging means 131.

  From the rear side (back side) of the connector 130, one end side of the L-shaped connector pin 132 is press-fitted and attached. The other end side of the connector pin 132 is inserted into a through hole 140 formed in the wiring pattern of the circuit board 112 and joined to the circuit board 112 with solder. A cover 133 is attached to the rear side (back side) of the connector 130 to prevent the connector pin 132 from being exposed, and the connector pin 132 is protected.

  According to the structure shown in FIGS. 1 to 3, the weight can be reduced by making the lower casing 102 made of resin, and by forming a plurality of ribs 126, 126 on the bottom surface of the recess 111, the thickness can be reduced. A reduction in rigidity of the lower casing 102 due to the thinning is prevented.

  In particular, the rib 125 reinforces the integral structure of the bearing holder 124 and the lower casing 102, and a structure in which minute displacement of the bearing holder 124 with respect to the lower casing 102 is difficult to occur is obtained. This displacement becomes a cause of vibration when the impeller 103 rotates. Therefore, the above structure is useful for obtaining low vibration characteristics while pursuing weight reduction.

  Moreover, the structure which couple | bonds the lower casing 102 and the support | pillar 107 by welding the front-end | tip of the projection part 107a of the support | pillar 107 is easy to automate a joining operation, and high productivity is acquired. Further, by making the lower casing 102 made of resin, even if the gap between the circuit board 112 on which the electronic component is mounted and the concave portion 111 of the lower casing 102 is reduced, the electrons due to the contact between the electronic component and the lower casing 102 are reduced. Short circuit between parts can be avoided. In addition, it is not necessary to arrange an insulating sheet to prevent a short circuit between electronic components, and the number of components can be reduced.

  In addition, the structure using the connector 130 improves the assembly workability related to wiring connection. In addition, the outermost peripheral edge of the lower casing 102 is a portion where the blowout port 108 is formed, but since the lower casing 102 is made of resin, the degree of freedom of the shape of the portion where the blowout port 108 is formed can be increased. It becomes easy to control the air direction of the air from the outlet 108. As a result, noise caused by air blowing can be reduced.

(2) Second embodiment (see FIG. 4)
The basic structure is the same as in the first embodiment. Hereinafter, a different part from 1st Embodiment is demonstrated. In this embodiment, the lower casing 102, the bearing holder 124, and the connector (connector housing) 130 are formed by integral molding of resin. That is, the bearing holder 124 and the connector 130 are formed as a part of the lower casing 102. The connector pin 132 is press-fitted into and attached to the connector (connector housing) 130, and one end side of the connector pin 132 is inserted into the through hole 140 of the circuit board 112 and joined by soldering.

  According to this structure, since the lower casing 102 and the connector (connector housing) 130 are formed by integral molding of resin, the mounting operation of the connector 130 on the lower casing 102 can be omitted. Further, since the lower casing 102 and the connector 130 are formed by integral molding of the resin, the load applied to the connector 130 during the insertion operation and the extraction operation of the mating connector on the wiring side is affected by the connector pin 132 and the circuit board. It is possible to prevent the concentration at the junction with 112 and improve the reliability.

(3) Third embodiment (see FIG. 5)
In this example, the lower casing 102 and the cylindrical bearing holder 124 are formed by integral molding of resin. A metal bearing sleeve 141 having a pair of ball bearings 127 and 128 fitted inside is fitted inside the cylindrical bearing holder 124. The connector 130, which is a separate member, is mounted on the lower surface of the lower casing 102, and one end side of the connector pin 132 is inserted into the through hole 140 of the circuit board 112 and joined with solder. According to this structure, the bearing device can be configured as a sub-assembly, and high accuracy can be obtained for the coaxiality of the bearing.

(4) Fourth embodiment (see FIGS. 6 to 7)
FIG. 6 is a perspective view showing another embodiment of the lower casing 102, and FIG. 7 is a side view seen from a direction perpendicular to the axis. In this embodiment, the lower casing 102, the bearing holder 124, and the connector (connector housing) 130 are formed by integral molding of resin, as in FIG.

  Hereinafter, differences from FIG. 4 will be described. In the structure of FIG. 6, as in the structure of FIG. 4 (FIG. 1), a plurality of radial ribs 125 and concentric ribs 126 are formed on the bottom surface of the recess 111 of the lower casing 102 to reduce the thickness. This prevents a decrease in rigidity. In addition, in the present embodiment, as shown in FIGS. 6 and 7, a protrusion 151 (a protrusion 151 protruding downward by forming the recess 111 is formed), and a diameter outward from the protrusion 151. A plurality of reinforcing ribs 153 are formed to connect the extending flat portion 152 (the flat portion on the lower surface side corresponding to the step portion 123 of the lower casing).

  The rib 153 has a triangular shape and is provided with a plurality of locations in the circumferential direction. The rib 153 is integrally formed as a part of the lower casing 102 when the lower casing 102 is formed. The rib 153 reinforces the integral structure of the projecting portion 151 and the flat portion 152 and increases the rigidity of the entire lower casing 102. Simultaneously with the formation of the rib 153, a rib 154 that connects between the connector (connector housing) 130 and the flat portion 152 of the lower casing 102 is integrally formed as a part of the lower casing 102.

  In this structure, the lower casing 102 is further reinforced by the reinforcing rib 153 that connects the side surface of the projecting portion 151 and the flat portion 152, and the rigidity thereof is ensured. Further, the connector 130 is reinforced by connecting the lower casing 102 and the connector (connector housing) 130 with a rib 154.

  In general, connector housings are subject to load and deformation and breakage during insertion and removal of the mating connector of the wiring to be connected, and force concentrates on the electrical connection area, resulting in poor contact. It is likely to occur. In the structure shown in FIGS. 6 and 7, the presence of the rib 154 makes it difficult for the connector 130 to be deformed, and the force is prevented from concentrating on the joint between the connector pin 132 (see FIG. 4) and the circuit board 112. Therefore, a highly reliable connector structure can be obtained.

DESCRIPTION OF SYMBOLS 100 ... Centrifugal fan, 101 ... Upper casing, 102 ... Lower casing, 103 ... Impeller, 104 ... Suction port, 106 ... Blade, 107 ... Strut, 107a ... Projection part, 108 ... Outlet, 110 ... Motor, 111 ... Recessed part, DESCRIPTION OF SYMBOLS 112 ... Circuit board, 113 ... Rib, 114 ... Recessed part, 115 ... Flange part, 118 ... Flange, 119 ... Through-hole, 121 ... Shroud, 122 ... Main plate, 123 ... Step part, 124 ... Bearing holder, 125 ... Rib, 126 ... Ribs, 127 ... Ball bearings, 128 ... Ball bearings, 129 ... Projections, 130 ... Connectors, 131 ... Engaging means, 132 ... Connector pins, 133 ... Covers, 135 ... Shafts, 136 ... Bushes, 137 ... Openings, 140 ... through hole.

Claims (9)

A resin upper casing;
A lower casing made of resin,
A centrifugal fan comprising: an impeller disposed rotatably between the upper casing and the lower casing;
A recess is formed in the lower casing,
In the recess,
A hollow cylindrical bearing holder that is formed as a part of the lower casing and is erected in the axial direction for holding the rotating shaft member of the impeller in a rotatable state;
Centrifugal fan in which radial and concentric ribs are formed.   The centrifugal fan according to claim 1, wherein the radially formed ribs connect an inner periphery of the recess and an outer periphery of the bearing holder. A support column extending in the direction of the lower casing is provided at the peripheral portion of the upper casing,
The centrifugal fan according to claim 1 or 2, wherein the support column and the lower casing are welded.   The centrifugal fan as described in any one of Claims 1 thru | or 3 with which the connector to which the wiring from the said lower casing and the outside is connected is engaged by the engaging means.   The centrifugal fan according to any one of claims 1 to 3, wherein a connector to which an external wiring is connected is formed as a part of the lower casing.   The centrifugal fan according to any one of claims 1 to 5, wherein a bearing sleeve having a pair of bearings is fitted inside the bearing holder.   The rib which connects the outer peripheral surface of the protrusion part which protrudes in the lower surface of the said lower casing, and the plane part extended radially outward from the said protrusion part is provided. Centrifugal fan.   The centrifugal fan according to claim 5, wherein a rib is provided to connect the connector and a flat portion extending radially outward from a protruding portion protruding from a lower surface of the lower casing. On the side surface excluding the support column interposed between the upper casing and the lower casing, a fluid outlet is provided,
The centrifugal fan according to any one of claims 1 to 8, wherein the blowout port has a shape in which a fluid to be blown out is guided obliquely downward.

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