JP2017002815A - Air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air blower capable of suppressing peeling of flow flowing downward along the inner wall surface of a suction conduit.SOLUTION: An air blower 1 includes a centrifugal fan 3, a scroll casing 2 housing the fan 3, and a suction conduit 4 distributing air suctioned inside the scroll casing 2 to an inside passage 24 running inside the conduit and an outside passage 25 running outside the conduit. The suction conduit 4 includes, at an upstream end part into which air is suctioned, peeling suppression means configured to suppress peeling of air flow flowing along the inner peripheral wall surface of the suction conduit 4. The peeling suppression means is an annular distributing plate 40 that is provided at the upstream end part of the suction conduit 4, and of which an outer peripheral part is positioned radially outward with respect to an inner peripheral edge.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a blower provided with a centrifugal fan.

  Patent Document 1 discloses a blower device including a suction conduit having a trumpet on the downstream side in either a scroll casing that houses a centrifugal fan or a centrifugal fan. The length Δb along the blade leading edge from the intersection of the extension line of the rear end portion of the suction conduit and the blade leading edge of the centrifugal fan to the blade tip of the centrifugal fan is defined as b. Then, the value of Δb / b is set larger than 8% and smaller than 30%.

  Since the blower device has a suction conduit that satisfies this condition, the suction conduit is installed close to the side plate side of the fan. With this action, in Patent Document 1, since the flow of the working fluid along the side plate is forced by the suction conduit, separation of the flow generated at the front end portion of the side plate of the fan is prevented, and the drift to the main plate side of the fan is prevented. There is a description that can be prevented.

JP 59-15696 A

  Although the air blower of patent document 1 has the technique which can suppress flow separation about the flow between the outer peripheral surface of a suction conduit and the front-end part of a side plate of a fan, about the flow which flows down along the inner wall face of a suction conduit Has the problem of peeling. In the air blower having the suction conduit, there is room for improving the fan efficiency of the air blower by suppressing the separation of the flow along the inner wall surface that flows inside the suction conduit. It is insufficient.

  Since the blower of patent document 1 has the scroll casing surrounding the circumference of a centrifugal fan, since the distance with a fan is short in the vicinity of the nose part which is the starting point of the spiral shape in a scroll casing, it was blown out from the fan. The flow is easy to collide. This phenomenon becomes a factor that disturbs the flow of the working fluid in the scroll casing, and causes a problem that the fan efficiency decreases and the noise increases.

  One of the disclosed inventions has been made in view of the above-described problems, and an object thereof is to provide a blower device that can suppress separation of a flow flowing down along an inner wall surface of a suction conduit. .

  One of the disclosed inventions has been made in view of the above-described problems, and an object thereof is to provide a blower capable of suppressing a flow that collides with a nose portion of a scroll casing.

  The disclosed invention employs the following technical means to achieve the above object. Further, the reference numerals in parentheses described in the claims and in this section are examples showing the correspondence with specific means described in the embodiments described later as one aspect, and the technical scope of the disclosed invention It is not intended to limit.

The disclosed blower includes a centrifugal fan (3) that sucks fluid along the rotation axis (30) and blows it in the centrifugal direction, and a suction port (20) and a fan corresponding to the fan suction section (34). A blower outlet (23) through which the fluid blown in the centrifugal direction is blown out, a fan casing (2) for housing the fan, and a pipe provided inside the suction port, and inside the fan casing A suction conduit (4) that divides the sucked fluid into an inner passage (24) that flows inside the tube and an outer passage (25) that flows between the tube and the suction port;
The suction conduit is provided with a separation suppressing means (40; 140; 440; 540) that suppresses separation of a fluid flow flowing along the inner peripheral wall surface of the suction conduit at an upstream end where fluid is sucked.

  According to the present invention, since the upstream end portion is provided with the separation suppressing means for suppressing separation of the fluid flow flowing along the inner wall peripheral surface of the suction conduit, separation of the flow along the inner wall peripheral surface from the inlet portion of the suction conduit can be suppressed. . According to this action, separation from the inner peripheral wall surface can be suppressed in a wide range from the inlet portion to the outlet portion of the suction conduit. When the separation in the suction conduit can be suppressed in this way, the pressure resistance in the tube is reduced, so that the suction air volume can be secured and the suction conduit can exhibit a predetermined ability. Therefore, this invention can provide the air blower which can suppress peeling of the flow which flows down along the inner peripheral wall surface of a suction conduit, and can improve the fan efficiency of an air blower.

The disclosed blower includes a centrifugal fan (3) that sucks fluid along the rotating shaft (30) and blows it in the centrifugal direction, and a suction port (20) corresponding to the fan suction portion (34). And a scroll casing (2) that includes a side wall (21) that spirally surrounds the fan and accommodates the fan, and a blower outlet (23) through which the fluid blown in the centrifugal direction of the fan is blown out. , A member having a side wall (52) extending in the circumferential direction around the rotation axis and extending toward the suction port side in the downstream direction and provided inside the suction port, and the fluid flowing along the suction port A guide member (5; 105) for guiding to the part,
The guide member intersects with a line segment (L1) connecting the nose portion (22), which is the starting point of the spiral shape on the side wall of the scroll casing, and the rotary shaft when the guide member is viewed in a direction along the rotary shaft. It is provided in an arbitrary range except for.

  In the vicinity of the nose portion of the scroll casing surrounding the centrifugal fan, the distance from the fan is short, so that the flow blown out from the fan collides, and this phenomenon disturbs the flow and causes an increase in noise. According to the present invention, since the guide member is not provided at a location intersecting the line connecting the nose portion of the scroll casing and the rotation shaft, the flow blown out from the fan near the nose portion strongly collides with the nose portion. That can be reduced. This is because in the vicinity of the nose where the suction fluid is not guided by the guide member, the flow is biased to the opposite side away from the suction port due to the characteristics of the centrifugal fan. This is because it is difficult to collide over a wide area.

  On the other hand, in the place where the guide member is present, the suction fluid flows along the side wall extending toward the suction port side in the downstream direction, so that the velocity distribution near the suction port is larger than the flow near the nose portion described above. growing. According to the fluid guiding function by the guide member, it is possible to improve the non-uniformity of the fluid flow blown in the centrifugal direction, which is unique to the centrifugal fan, so that the fan efficiency can be improved. As mentioned above, this invention can provide the air blower which can suppress the flow which collides with the nose part of a scroll casing, and can suppress the fall of the fan efficiency and noise increase of an air blower.

It is the top view which looked at the suction inlet side in the suction direction about the air blower of 1st Embodiment. It is sectional drawing which looked at the II-II cut surface about the air blower of FIG. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 2nd Embodiment. It is sectional drawing which looked at the IV-IV cut surface about the air blower of FIG. It is a fragmentary sectional view explaining the state of the air which flows through a suction conduit about the air blower of a 2nd embodiment. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 3rd Embodiment. It is sectional drawing which looked at the VII-VII cut surface about the air blower of FIG. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 4th Embodiment. It is sectional drawing which looked at the IX-IX cut surface about the air blower of FIG. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 5th Embodiment. It is sectional drawing which looked at the XI-XI cut surface about the air blower of FIG. It is a fragmentary sectional view explaining the state of the air which flows through the upstream edge part of a suction conduit about the air blower of 5th Embodiment. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 6th Embodiment. It is sectional drawing which looked at the XIV-XIV cut surface about the air blower of FIG. It is a fragmentary sectional view explaining the state of the air which flows through the upstream edge part of a suction conduit | pipe about the air blower of 6th Embodiment. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 7th Embodiment. It is sectional drawing which looked at the XVII-XVII cut surface about the air blower of FIG. It is the top view which looked at the suction inlet side in the suction direction about the air blower of 8th Embodiment. It is sectional drawing which looked at the XIX-XIX cut surface about the air blower of FIG.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. In addition to combinations of parts that clearly indicate that each embodiment can be combined specifically, the embodiments may be partially combined even if they are not clearly specified, unless there is a problem with the combination. Is possible.

(First embodiment)
The blower 1 according to the first embodiment will be described with reference to FIGS. 1 and 2. The blower 1 is a device used for various applications such as a blower for ventilation, forced air circulation, and an air conditioner. Here, as an example, the blower 1 will be described as an apparatus that is applied to a vehicle air conditioner and that provides conditioned air toward the vehicle interior. In this case, the air blower 1 is installed with the air conditioning unit in the space behind the instrument panel in the vehicle interior, for example.

  The blower device 1 includes at least a motor 31, a centrifugal fan 3, and a scroll casing 2. The motor 31 is disposed on the side opposite to the suction port 20 formed in the scroll casing 2 and is driven to rotate around the rotation axis of the fan 3 fixed to the motor shaft 30. The fan 3 rotates around the rotation axis by the rotational driving force of the motor 31.

  The fan 3 is a centrifugal impeller that sucks air in a direction along the rotation axis (rotation axis direction) and blows it out in a radial direction or a centrifugal direction. As the fan 3, for example, a sirocco fan or a turbo fan can be used.

  The fan 3 according to the first embodiment is a sirocco fan, and includes a large number of blades fixed in a ring shape at regular intervals by a disk-shaped bottom plate 32 and a top plate 33, and a rotating shaft, and is generally cylindrical. Presents the body. The rotation shaft is a boss portion provided at the center of the bottom plate 32, and a hole portion through which the motor shaft 30 is fixed is formed in the boss portion. The fan 3 has a suction portion 34 formed by an inner peripheral edge opening of the top plate 33 on the side opposite to the bottom plate 32 of the cylindrical body. For example, each blade is a strip-shaped blade having a short width and warped forward. When the fan 3 is rotated by the rotational driving force of the motor 31, air, which is an example of a working fluid, flows in the direction of the rotation axis along the motor shaft 30 from the suction portion 34, and further flows in the radial direction from between adjacent blades. , Blown out radially as a whole.

  The scroll casing 2 is a case in which a suction port 20 corresponding to a suction portion 34 of the fan 3 and a blowout port 23 through which air blown in the centrifugal direction of the fan 3 is blown out are provided to house the fan 3 therein. is there. The scroll casing 2 forms a spiral air passage around the fan 3. The ventilation path is a passage that draws a scroll curve having a certain spread angle around the fan 3, starting from the nose portion 22 of the scroll casing 2. The nose portion 22 is a spiral-shaped starting point on the side wall 21 of the scroll casing 2. Therefore, when the nose portion 22 is set to zero degrees, the ventilation path increases as the winding angle, which is the rotation angle in the circumferential direction around the rotation axis of the fan 3, increases, that is, as the air flow proceeds downstream. The cross-sectional area of the passage is enlarged.

  The scroll casing 2 has a side wall 21 that spirally extends from the nose portion 22 so as to face the outer peripheral portion of the fan 3, and is a fan casing that houses the fan 3. The side wall 21 forms a spiral passage extending between the outer periphery of the fan 3 and a spiral shape. The scroll casing 2 includes an annular top plate casing extending from the upper end of the side wall 21 so as to be orthogonal to the rotation axis, and an annular bottom plate casing extending from the lower end of the side wall 21 toward the rotation axis. . The bottom plate casing extends inward from the lower end of the spirally extending side wall 21 toward the motor shaft 30 and covers the bottom plate 32 of the fan 3 below.

  A motor 31 is fixed to the bottom plate casing in a state in which the outer peripheral portion is fitted in the opening. The motor 31 is fixed to the scroll casing 2 by being attached to the bottom plate casing by fastening means such as bolts and nuts. The top plate casing and the bottom plate casing are parts connected by the side wall 21. The top casing, the bottom casing and the side wall 21 are integrated to form the scroll casing 2.

  The scroll casing 2 is formed with a suction port 20 into which air is sucked by rotation of the fan 3, and the suction port 20 is an opening portion of a bell mouth formed in an annular top plate casing. The suction port 20 is a through hole having a smaller diameter than the outer peripheral edge of the fan 3. The inner peripheral edge forming the suction port 20 is close to the inner peripheral edge of the suction portion 34 of the fan 3. It is preferable that the gap dimension formed by both is set small from the viewpoint of improving the performance of the blower 1.

  The blower 1 includes a suction conduit 4 provided inside the suction port 20 of the scroll casing 2. The suction conduit 4 includes a trumpet-shaped cylindrical portion 41 having a passage cross-sectional area formed larger than a passage in which an upstream end opening 410 serving as an inlet portion and a downstream end opening 411 serving as an outlet portion are located in an intermediate portion, And a rectifying plate portion 40 that is provided at the upstream end of the shape portion 41 and forms an annular plate. A part of the tubular portion 41 on the upstream end opening 410 side is located outside the scroll casing 2, and the remaining portion on the downstream end opening 411 side is located inside the scroll casing 2. Therefore, the suction conduit 4 is provided inside the suction port 20 such that the upstream end opening 410 is located outside the scroll casing 2 and the downstream end opening 411 is located inside the scroll casing 2.

  The cylindrical portion 41 of the suction conduit 4 has a trumpet shape extending in the circumferential direction around the rotation axis and extending toward the suction port 20 toward the downstream direction. According to this shape, the air sucked into the suction conduit 4 flows along the cylindrical portion 41 and contributes to being guided to the suction portion 34 of the fan 3. The suction conduit 4 is a member that divides the air sucked into the scroll casing 2 into an inner passage 24 that flows inside the tubular portion 41 and an outer passage 25 that flows between the tubular portion 41 and the suction port 20. is there. The suction conduit 4 is integrally provided and supported by the bell mouth of the scroll casing 2 via a plurality of support plates 42. The support plate 42 connects the inner peripheral edge of the suction port 20 and the cylindrical portion 41 at equal intervals.

  The suction conduit 4 is provided with a separation suppressing means for suppressing separation of the fluid flow flowing along the inner peripheral wall surface of the suction conduit 4 at the upstream end where the fluid is sucked. As illustrated in FIG. 2, the air flowing along the separation suppressing means causes a flow along the inner peripheral wall surface of the cylindrical portion 41 on the further downstream side, so that the flow separation from the inner peripheral wall surface of the cylindrical portion 41 is performed. The effect which suppresses is produced. The rectifying plate portion 40 which is an example of the peeling suppressing unit has a cross-sectional shape orthogonal to the motor shaft 30 or the rotation axis.

  The rectifying plate portion 40 is an annular plate portion whose outer peripheral portion is located on the outer side of the diameter than the upstream end opening 410. The rectifying plate portion 40 extends toward the outer peripheral portion so as to intersect the motor shaft 30 or the rotation axis. Accordingly, the cross-section of the rectifying plate portion 40 is not limited to a shape that is orthogonal to the motor shaft 30 or the rotation axis, and is along the inner peripheral wall surface of the cylindrical portion 41 as long as it is a shape that intersects a non-parallel angle. Demonstrates the function of suppressing flow separation.

  The fan 3, the scroll casing 2, and the suction conduit 4 are each formed of a molded product of, for example, polypropylene (PP resin). Furthermore, when improving the intensity | strength of these each part, you may use PP resin containing predetermined amount of talc and glass fiber.

  In the case of a blower equipped with a centrifugal fan, the position of the maximum flow velocity vector in the air flow blown out from the fan is generated in a lower part on the side farther from the suction port 20 than the central part of the blade height. Therefore, the blower device 1 includes the suction conduit 4 so that the suction air flows along the inner peripheral wall surface of the cylindrical portion 41 extending toward the suction port toward the downstream side. The speed distribution near the suction port 20 is increased. Thereby, since the bias of the flow velocity distribution peculiar to the centrifugal fan 3 can be improved, the fan efficiency of the blower 1 can be improved, and the noise can be suppressed.

  Below, the effect which the air blower 1 of 1st Embodiment brings is described. The blower 1 includes a centrifugal fan 3, a scroll casing 2 that houses the fan 3, and air sucked into the scroll casing 2 into an inner passage 24 that flows inside the pipe and an outer passage 25 that flows outside the pipe. A suction conduit 4 for dividing. The suction conduit 4 is provided with a separation suppressing means that suppresses separation of the air flow flowing along the inner peripheral wall surface of the suction conduit 4 at the upstream end portion where air is sucked.

  According to this configuration, since the upstream end portion is provided with the separation suppressing means that suppresses separation of the air flow flowing along the inner peripheral wall surface of the suction conduit 4, the separation of the flow along the inner peripheral wall surface from the inlet portion of the suction conduit 4 is performed. Can be suppressed. According to this, separation of the flow from the inner peripheral wall surface can be suppressed in a wide range from the upstream end portion to the downstream end portion of the suction conduit 4. When the separation of the internal flow of the suction conduit 4 can be suppressed in this way, the pressure resistance in the pipe can be reduced. According to the reduction of the pressure resistance, the amount of suction air in the pipe can be secured, so that the efficiency improvement effect by the suction conduit 4 can be exhibited. Therefore, according to 1st Embodiment, the peeling of the flow which flows down along the inner peripheral wall surface of the suction conduit 4 can be suppressed, and the air blower 1 which can improve fan efficiency can be provided.

  Moreover, one of the peeling suppression means is an annular rectifying plate portion 40 that is provided at the upstream end portion of the suction conduit 4 and whose outer peripheral portion is located on the outer side of the inner periphery. According to this configuration, since the annular rectifying plate portion 40 is provided at the upstream end portion of the suction conduit 4, the air sucked into the suction conduit 4 along the surface of the rectifying plate portion 40 is changed to the surface of the rectifying plate portion 40. It can flow down smoothly along the inner peripheral wall surface of the suction conduit 4 from above. This smooth rectification can suppress separation of the flow along the inner peripheral wall surface from the inlet portion of the suction conduit 4. According to such introduction of air, separation of the flow from the inner peripheral wall surface can be suppressed in a wide range from the upstream end portion to the downstream end portion of the suction conduit 4. If the separation of the flow in the suction conduit 4 can be suppressed, the pressure resistance in the pipe can be reduced, so that the amount of suction air in the pipe can be secured and the fan efficiency can be improved.

(Second Embodiment)
In 2nd Embodiment, the air blower 101 which is the other form of 1st Embodiment is demonstrated with reference to FIGS. The air blower 101 is different from the air blower 1 of the first embodiment in peeling prevention means. In the second embodiment, components having the same reference numerals as those in the drawing according to the first embodiment and configurations not described are the same as those in the first embodiment and have the same effects. In the second embodiment, only parts different from the first embodiment will be described.

  As shown in FIG. 3 and FIG. 4, the blower 101 includes a further stripping suppression unit in addition to the rectifying plate portion 40 that is the stripping suppression unit in the blower 1. The peeling suppression means in the blower 101 includes at least one of the convex portion 140a and the concave portion 140b formed on the surface of the rectifying plate portion 140 and at least one of the convex portion 141a and the concave portion 141b formed on the inner peripheral wall surface of the suction conduit 104. And comprising. The rectifying plate portion 140 in the blower 101 has the same shape as that of the rectifying plate portion 40, except that convex portions 140a and concave portions 140b are formed on the surface thereof. The cylindrical portion 141 of the suction conduit 104 has the same shape as the cylindrical portion 41, except that a convex portion 141a and a concave portion 141b are formed on the surface thereof.

  As shown in FIG. 5, the surface roughness is provided by the concave portions and the convex portions formed on the inner peripheral wall surface of the suction conduit 104 and the surface of the rectifying plate portion 140, thereby disturbing the boundary layer on the surface, Transition from laminar flow to turbulent flow. Since the flow on the surface transitions from laminar flow to turbulent flow in this way, the separation point on the surface shifts backward, so that the pressure resistance in the pipe decreases. The irregularities formed in this way have the effect of stirring the air flow, and when the surface flow is stirred, the upper layer fast flow mixes with the surface flow slowed by viscosity as shown in FIG. Will rise and become difficult to peel off. Thus, when peeling becomes small, pressure resistance will reduce.

  According to the blower device 101 of the second embodiment, the peeling suppressing means includes at least one of the convex portion 140 a and the concave portion 140 b formed on the surface of the rectifying plate portion 140 and the convex portion formed on the inner peripheral wall surface of the suction conduit 104. At least one of the part 141a and the recessed part 141b. According to this, since it is possible to form a flow that is difficult to separate as described above in both the rectifying plate portion 140 and the tubular portion 141, a wide range from the upstream end portion of the suction conduit 4 toward the downstream end portion. This can contribute to suppressing the separation of the flow from the inner peripheral wall surface.

  Further, it is preferable that at least one of the convex portion and the concave portion is provided so that the upstream side in the suction conduit 104 is denser than the downstream side. In other words, at least one of the convex portion and the concave portion is provided such that the side closer to the upstream end opening 1410 in the suction conduit 104 is denser than the side closer to the downstream end opening 1411. According to this, since many protrusions or recesses are provided on the upstream side of the suction conduit 104, the air sucked into the suction conduit 104 is smooth along the inner peripheral wall surface of the suction conduit 104 on the upstream side. Can flow down. By forming a flow that is difficult to separate on the upstream side in this way, flow separation from the inner peripheral wall surface can be suppressed in a wide range from the upstream end portion to the downstream end portion of the suction conduit 104.

(Third embodiment)
In 3rd Embodiment, the air blower 201 which is the other form of 2nd Embodiment is demonstrated with reference to FIG.6 and FIG.7. The air blower 201 is different from the air blower 101 of the second embodiment in peeling suppression means. In the third embodiment, the components denoted by the same reference numerals as those in the drawings according to the first and second embodiments and the configurations not described are the same as those in the first and second embodiments, and have the same effects. is there. In the third embodiment, only parts different from the first and second embodiments will be described.

  As shown in FIG. 6 and FIG. 7, the blower 201 does not include a peeling suppression unit such as a convex portion or a concave portion in the cylindrical portion 41 with respect to the peeling suppression unit in the blower 101. Therefore, the peeling suppression means in the blower 201 is configured to include at least one of the convex portion 140 a and the concave portion 140 b formed on the surface of the rectifying plate portion 140. The surface roughness is provided by the concave portions and the convex portions formed on the surface of the rectifying plate portion 140 in the suction conduit 204, whereby the boundary layer on the surface is disturbed and the flow transitions from laminar flow to turbulent flow. As the flow on the surface transitions from laminar flow to turbulent flow, the separation point on the surface shifts backward, and when the flow on the surface is stirred, the surface layer flow slowed down by the viscosity is The faster flow of the mixture is mixed and the speed is increased, making it difficult to peel off.

  According to the blower device 201 of the third embodiment, the peeling suppression unit includes at least one of the convex portion 140a and the concave portion 140b formed on the surface of the rectifying plate portion 140. According to this, since it is possible to form a flow that hardly separates as described above in the rectifying plate portion 140, the flow from the inner peripheral wall surface in a wide range from the upstream end portion to the downstream end portion of the suction conduit 204. This can contribute to the suppression of peeling.

(Fourth embodiment)
In 4th Embodiment, the air blower 301 which is the other form of 2nd Embodiment is demonstrated with reference to FIG.8 and FIG.9. The blower device 301 is different from the blower device 101 of the second embodiment in the peeling suppressing means. In the fourth embodiment, the components denoted by the same reference numerals as those in the drawings according to the first and second embodiments and the configurations not described are the same as those in the first and second embodiments and have the same effects. is there. In the fourth embodiment, only parts different from the first and second embodiments will be described.

  As shown in FIG. 8 and FIG. 9, the blower 301 does not include a stripping suppression unit such as a convex portion or a concave portion in the rectifying plate portion 40 with respect to the stripping suppression unit in the blower 101. Therefore, the peeling suppression means in the blower 301 is configured to include at least one of the convex portion 141a and the concave portion 141b formed on the inner peripheral wall surface of the cylindrical portion 141. The surface roughness is provided by the concave portions or the convex portions formed on the inner peripheral wall surface of the cylindrical portion 141 in the suction conduit 304, so that the boundary layer on the surface is disturbed, and the flow transitions from laminar flow to turbulent flow. In this way, the flow on the inner peripheral wall surface of the cylindrical portion 141 transitions from laminar flow to turbulent flow, so that the separation point on the surface shifts backward, and when the flow on the surface is stirred, the viscosity is slower. The flow of the upper layer is mixed with the fast flow of the upper layer, and the speed is increased, so that the separation becomes difficult.

  According to the blower device 301 of the fourth embodiment, the peeling suppression means is formed including at least one of the convex portion 141a and the concave portion 141b formed on the inner peripheral wall surface of the cylindrical portion 141. According to this, since it is possible to form a flow that is difficult to separate as described above on the inner peripheral wall surface of the cylindrical portion 141, the inner periphery in a wide range from the upstream end portion to the downstream end portion of the suction conduit 304 is formed. This can contribute to suppressing the separation of the flow from the wall surface.

(Fifth embodiment)
5th Embodiment demonstrates the air blower 401 which is the other form of 1st Embodiment with reference to FIGS. 10-12. The blower device 401 is different from the blower device 1 of the first embodiment in peeling prevention means. In the fifth embodiment, components denoted by the same reference numerals as those in the drawing according to the first embodiment and configurations not described are the same as those in the first embodiment and have the same effects. In the fifth embodiment, only parts different from the first embodiment will be described.

  As shown in FIGS. 10 and 11, the blower 401 includes a concavo-convex shape 440 formed on the outer peripheral portion of the upstream end portion of the suction conduit 404 as a peeling suppressing means. The uneven shape 440 is provided on the outer peripheral edge forming the upstream end opening 410. That is, on the outer periphery of the upstream end portion of the suction conduit 404, convex portions protruding outward in the diameter and concave portions recessed on the center side are alternately formed over the entire circumference.

  As shown in FIG. 12, since the surface roughness is provided by the concave and convex portions formed at the upstream end portion of the suction conduit 404, the boundary layer is disturbed at the inlet portion of the suction conduit 404, and turbulence is caused from the laminar flow. Transition to the flow. When the air flow at the inlet portion is stirred in this manner, the flow of the upper layer is mixed with the flow of the upper layer, which is slowed by the viscosity, and the speed is increased, and the flow is difficult to separate inside the tubular portion 41 on the downstream side. Become. In addition, as shown in FIG. 12, a vortex is formed at the upstream end of the suction conduit 404 from the valley side of the uneven portion to the mountain side, and the vortex flows toward the surface along the extension line of the peak of the mountain. make. On the inner side of the downstream cylindrical portion 41, it is possible to suppress peeling by being suppressed by this flow. Moreover, when peeling becomes small, the pressure resistance in the cylindrical part 41 will decrease, and since the suction | inhalation air volume in the suction conduit 404 can be ensured, the efficiency improvement effect by the suction conduit 404 can be exhibited.

  According to the blower device 401 of the fifth embodiment, a flow that is difficult to peel off can be formed at the inlet portion of the suction conduit 404 as described above, so that the width from the upstream end portion to the downstream end portion of the suction conduit 404 is wide. This can contribute to suppressing the separation of the flow from the inner peripheral wall surface.

(Sixth embodiment)
In 6th Embodiment, the air blower 501 which is the other form of 1st Embodiment is demonstrated with reference to FIGS. The air blower 501 is different from the air blower 1 of the first embodiment in peeling prevention means. In the sixth embodiment, components denoted by the same reference numerals as those in the drawing according to the first embodiment and configurations not described are the same as those in the first embodiment and have the same effects. In the sixth embodiment, only parts different from the first embodiment will be described.

  As shown in FIG. 13 and FIG. 14, the blower 501 includes a concavo-convex shape formed on the outer peripheral portion of the rectifying plate portion 540 in the suction conduit 504 as a peeling suppressing means. On the outer periphery of the rectifying plate portion 540 in the suction conduit 504, convex portions protruding outward in the diameter and concave portions recessed toward the center are alternately formed over the entire circumference.

  As illustrated in FIG. 15, the surface roughness is provided by the concave and convex portions formed on the outer peripheral portion of the upstream end portion in the suction conduit 504, so that the boundary layer is disturbed in the flow along the rectifying plate portion 540, Transition from laminar flow to turbulent flow. In addition to the above-described rectifying effect by the rectifying plate portion 540, when the air flow along the rectifying plate portion 540 is stirred, the flow of the upper layer is mixed with the flow of the upper layer, which is slowed by the viscosity, and the speed increases. The flow is difficult to peel off in the tubular portion 41. Further, as shown in FIG. 15, at the upstream end portion of the suction conduit 504, a vortex that wraps around from the valley side of the uneven portion to the mountain side is formed, and the vortex flows toward the surface along the extension line of the peak of the mountain. Therefore, it is restrained by this flow inside the cylindrical portion 41 on the downstream side, and peeling can be suppressed. Moreover, when peeling becomes small, the pressure resistance in the cylindrical part 41 will decrease, and since the amount of suction air in the suction conduit 504 can be ensured, the efficiency improvement effect by the suction conduit 504 can be exhibited.

  According to the air blower 501 of 6th Embodiment, in addition to the rectification effect by the baffle plate part 540, the flow which is hard to peel by the uneven | corrugated shape of the outer peripheral part of the baffle plate part 540 can be formed. Therefore, the effect of suppressing the separation of the flow from the inner peripheral wall surface in a wide range from the upstream end portion to the downstream end portion of the suction conduit 504 can be further enhanced.

(Seventh embodiment)
In the seventh embodiment, a blower 601 that is another form of the first embodiment will be described with reference to FIGS. 16 and 17. The air blower 601 is different from the air blower 1 of the first embodiment in that a guide member 5 is provided instead of the suction conduit 4. In the seventh embodiment, components denoted by the same reference numerals as those in the drawing according to the first embodiment and configurations not described are the same as those in the first embodiment and have the same operational effects. In the seventh embodiment, only parts different from the first embodiment will be described.

  As shown in FIGS. 16 and 17, the blower 601 has a side wall 52 that extends in the circumferential direction around the rotation axis and extends toward the suction port 20 toward the downstream direction, and is provided inside the suction port 20. A guide member 5 is provided. The guide member 5 has a function of guiding the air flowing along the side wall 52 to the suction portion 34 of the fan 3 by the suction force of the fan 3. In addition, the guide member 5 acts to strengthen the flow velocity vector that has been directed to the rotation axis direction in the radial direction, that is, the direction perpendicular to the rotation axis, with respect to the air sucked into the suction port 20.

  As shown in FIG. 16, when the guide member 5 is viewed in a plan view in the direction along the rotation axis, the guide member 5 is provided at a location that does not intersect the line segment L1 connecting the nose portion 22 of the scroll casing 2 and the rotation axis. It has been. That is, the guide member 5 is a fan-like member in a plan view provided inside the suction port 20 except for a place intersecting the line segment L1. The guide member 5 is provided such that a line segment L1 is interposed between one end portion 53 and the other end portion 54 in the circumferential direction of the fan-shaped side wall 52. The guide member 5 is a member that divides the air sucked into the scroll casing 2 into an inner passage 124 that flows on the rotating shaft side with respect to the side wall 52 and an outer passage 125 that flows between the side wall 52 and the suction port 20. is there.

  Therefore, since the guide member 5 does not have the side wall 52 in the area on the nose portion 22 side with respect to the rotation shaft, the guide air 5 does not guide the intake air, and in the opposite side area, the intake air is sucked into the suction port 20 by the side wall 52. Can be guided towards. Thus, in the area on the side of the nose portion 22, the blowout characteristic peculiar to the centrifugal fan 3 is dominant, so that the maximum flow velocity vector is a flow velocity distribution biased to the opposite side away from the suction port 20. On the other hand, in the area on the opposite side, the suction air is guided to the suction port 20 side by the side wall 52, so that the velocity distribution near the suction port 20 is larger than the flow on the nose portion 22 side, and the maximum flow velocity vector is Close to the suction port 20.

  The guide member 5 is provided so that the whole is located inside the scroll casing 2. The upstream end 50 of the guide member 5 has a height matching the suction port 20 of the scroll casing 2 and is located inside the bell mouth. The downstream end 51 is located completely inside the scroll casing 2 and below the bell mouth (on the bottom plate 32 side). The guide member 5 is integrally provided and supported by the bell mouth of the scroll casing 2 via a plurality of support plates 55. The support plate 55 connects the inner peripheral edge of the suction port 20 and the side wall 52 at equal intervals.

  According to the air blower 601 of the seventh embodiment, the guide member 5 has a line segment L1 connecting the nose portion 22 of the scroll casing 2 and the rotation shaft when the guide member 5 is viewed in a plane along the rotation axis. It is provided in an arbitrary range excluding the intersection.

  In the vicinity of the nose portion 22 of the scroll casing 2 that houses the centrifugal fan 3, the distance from the fan 3 is short, so that the flow blown out of the fan 3 collides to disturb the flow inside the casing and increase noise. It is a problem to bring. Therefore, according to the blower 601, since the flow blown out from the fan 3 in the vicinity of the nose portion 22 is not guided by the guide member 5, the radial flow velocity vector can be prevented from being increased. Further, as described above, this flow has a flow velocity distribution in which the maximum flow velocity vector is biased to the opposite side away from the suction port 20. According to the formation of such a flow velocity vector, it is possible to reduce that the flow blown out from the fan 3 near the nose portion 22 strongly collides with the nose portion 22 or in a wide range. On the other hand, in the place where the guide member 5 is present, air flows along the side wall 52 extending toward the suction port 20 toward the downstream direction, so that the speed closer to the suction port 20 compared to the flow near the nose portion 22. The distribution, for example the radial velocity vector, increases. Therefore, according to the air blower 601, the air blower which can suppress the flow which collides with the nose part 22 can be provided, and the fall of fan efficiency and the noise increase can be suppressed.

(Eighth embodiment)
In the eighth embodiment, a blower 701, which is another form of the seventh embodiment, will be described with reference to FIGS. The shape of the guide member 105 differs in the air blower 701 with respect to the air blower 601 of 7th Embodiment. In the eighth embodiment, component parts denoted by the same reference numerals as those in the drawings according to the first and seventh embodiments and configurations not described are the same as those in the above-described embodiment, and have the same operational effects. In the eighth embodiment, only parts different from the above-described embodiment will be described.

  As shown in FIGS. 18 and 19, the blower 601 has a side wall 152 that extends in the circumferential direction around the rotation axis and extends toward the suction port 20 toward the downstream direction, and is provided inside the suction port 20. A guide member 105 is provided. The guide member 105 has a function of guiding the air flowing along the side wall 152 to the suction portion 34 of the fan 3 by the suction force of the fan 3.

  When the guide member 105 is viewed in a plan view in the direction along the rotation axis, the guide member 105 has a line between the one end portion 153 and the other end portion 154 in the circumferential direction of the fan-shaped side wall 152 in the same manner as the guide member 5. It is provided so that the minute L1 is interposed. The guide member 105 is formed in a shape in which one end 153 in the circumferential direction has a position where the downstream end 51 is advanced in the rotation direction R of the fan 3 relative to the upstream end 50. Further, the other end 154 in the circumferential direction of the guide member 105 is formed in a shape in which the downstream end 51 is located at a position advanced in the rotation direction R of the fan 3 relative to the upstream end 50.

  According to the blower 701 of the eighth embodiment, the air flowing through the inner passage 124 along the inner wall surface of the side wall 152 flows down from the upstream end 50 toward the downstream end 51 while proceeding in the rotation direction R. At this time, since the side wall 152 has a shape that extends in the rotation direction R from the upstream end 50 toward the downstream end 51 at the one end portion 153 and the other end portion 154 in the circumferential direction, the air is supplied to the one end portion 153 and the other end portion. 154 can be long. Thereby, the air blower 701 can enhance the effect of suppressing separation of air flowing along the guide member 105.

(Other embodiments)
The preferred embodiments of the disclosed invention have been described above, but the disclosed invention is not limited to the above-described embodiments, and various modifications can be made. The structure of the said embodiment is an illustration to the last, Comprising: The technical scope of the disclosed invention is not limited to the range of these description. The technical scope of the disclosed invention is indicated by the description of the scope of claims, and further includes all modifications within the meaning and scope equivalent to the description of the scope of claims.

  In the second and third embodiments described above, the rectifying plate portion 140 has a convex portion 140a and a concave portion 140b formed on the surface thereof, but one of the convex portion 140a and the concave portion 140b is formed. Even if it is the form which is, there exists the above-mentioned effect as a peeling suppression means.

  In the second embodiment and the fourth embodiment described above, the cylindrical portion 141 has the convex portion 141a and the concave portion 141b formed on the surface thereof, but one of the convex portion 141a and the concave portion 141b is formed. Even if it is the form which is, there exists the above-mentioned effect as a peeling suppression means.

DESCRIPTION OF SYMBOLS 2 ... Scroll casing (fan casing), 3 ... Fan 4 ... Suction conduit | pipe, 20 ... Suction port 23 ... Outlet, 24 ... Inner channel | path, 25 ... Outer channel | path 30 ... Motor shaft (rotating shaft), 34 ... Suction part 40, 140,540 ... Rectifying plate part (peeling suppression means)
440 ... Uneven shape (peeling suppression means)

Claims (9)

A centrifugal fan (3) that sucks fluid along the rotation axis (30) and blows it in the centrifugal direction;
A fan casing (2) which is provided with a suction port (20) corresponding to the suction portion (34) of the fan and a blowout port (23) through which the fluid blown in the centrifugal direction of the fan is blown out. )When,
A pipe provided inside the suction port, wherein the fluid sucked into the fan casing is an inner passage (24) flowing through the pipe and an outer passage flowing between the pipe and the suction port. A suction conduit (4) divided into (25);
With
The suction conduit is provided with a separation suppressing means (40; 140; 440; 540) for suppressing separation of a fluid flow flowing along an inner peripheral wall surface of the suction conduit at an upstream end portion where fluid is sucked. Blower device.   The said peeling suppression means is provided in the upstream edge part of the said suction conduit | pipe, and an outer peripheral part is a cyclic | annular baffle plate part (40) located in a diameter outer side rather than an inner peripheral edge, The Claim 1 characterized by the above-mentioned. Blower device.   The blower according to claim 2, wherein the peeling suppression means is at least one of a convex portion (140a) and a concave portion (140b) formed on the surface of the rectifying plate portion (140).   The blower according to claim 1, wherein the peeling suppression means is at least one of a convex portion (141a) and a concave portion (141b) formed on an inner peripheral wall surface of the suction conduit.   The peeling suppression means includes at least one of a convex portion (140a) and a concave portion (140b) formed on the surface of the rectifying plate portion (140), and a convex portion (141a) formed on the inner peripheral wall surface of the suction conduit. And at least one of the recesses (141b).   6. The blower according to claim 4, wherein at least one of the convex portion and the concave portion is provided so that an upstream side is denser than a downstream side in the suction conduit.   2. The blower according to claim 1, wherein the peeling suppression unit has a concavo-convex shape (440; 540) formed on an outer peripheral portion of an upstream end portion in the suction conduit. A centrifugal fan (3) that sucks fluid along the rotation axis (30) and blows it in the centrifugal direction;
A suction port (20) corresponding to the suction portion (34) of the fan and a blowout port (23) through which the fluid blown in the centrifugal direction of the fan is provided, and surrounds the fan in a spiral shape. A scroll casing (2) having a side wall (21) for accommodating the fan;
A member that is provided on the inner side of the suction port with a side wall (52) extending in the circumferential direction around the rotation axis and extending in the downstream direction toward the suction port side. A guide member (5; 105) for guiding the suction portion of the fan;
With
When the guide member is viewed in plan in the direction along the rotation axis, the guide member is a line segment connecting the nose portion (22) that is the spiral starting point on the side wall of the scroll casing and the rotation shaft. A blower characterized by being provided in an arbitrary range excluding a place intersecting (L1).   In the circumferential end portions (153, 154), the guide member (105) has a shape in which the downstream end (51) is positioned in the rotational direction (R) of the fan more than the upstream end (50). The blower according to claim 8, wherein the blower is formed.

Images