JP2010209887A - Casing for fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce pressure loss at a blow out channel while increasing a suction quantity of gas from a suction port further and increasing force pressing gas into the suction port (dynamic pressure of a fan). <P>SOLUTION: A casing body 5 includes a revolution channel 10 making gas sucked through an suction air opening part 9 opening at a part in a rotation direction of an impeller 2 on an outer side of a front wall 8 revolve in the same direction as a rotation direction of the impeller 2 and flow toward the suction port 3, and an introduction part 11 disposed at a terminal part of the revolution channel 10 and introducing gas made to flow by the revolution channel 10 to a suction port 3. A blow out channel continues to a part between an outer circumference of the impeller 2 and a blow out channel wall and is formed between a blow out channel wall and a connection wall connected toward the blow out port from a tongue part. A channel part where the tongue part faces the blow out channel wall in the blow out channel is constructed in such a manner that the channel on a side separating from a front wall in a rotary axial direction of the impeller is wider than that on a side getting close to the front wall. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a casing main body that houses a rotationally driven impeller, a front wall having a suction port for sucking gas along the direction of the rotational axis of the impeller, a rear wall disposed opposite to the front wall, A flow channel is formed between the front wall and the rear wall and the outer periphery of the impeller accommodated therein to flow gas toward a blowout opening that opens in a part of the impeller in the rotational direction. A circumferential inner wall, and the circumferential inner wall has a tongue portion having a minimum distance from the outer periphery of the impeller, and a blowout flow path to the blowout port that is continuous with the flow flow path. The present invention relates to a fan casing in which a continuous portion continuous with a flow path wall is a circulation end, and the flow path width of the flow channel is sequentially increased from the circulation start end to the circulation end.

  The fan including the fan casing as described above sucks gas (for example, air) from the suction port along the rotational axis direction of the impeller, and the sucked gas is centrifugally directed from the inside of the impeller toward the outer periphery. It is configured as a centrifugal fan that causes the discharged air to flow out from the air outlet.

In such a fan casing, a circular suction port is formed in the front wall, and gas is sucked from the suction port (see, for example, Patent Document 1). In the fan casing described in Patent Document 1, since the gas is simply sucked from the circular suction port, there is a possibility that the gas cannot be sucked efficiently from the suction port.
Therefore, in the conventional fan casing, a plurality of fixed wings for rotating the gas in the rotation direction of the impeller are disposed outside the front wall (portion before the gas is introduced into the suction port) (for example, , See Patent Document 2). In the fan casing described in Patent Document 2, the gas around the suction port is caused to flow to the front of the suction port while being guided and flowed in the rotation direction of the impeller by the fixed blades. Thereby, it becomes easy to suck in the gas around the suction port, and the flow rate of the gas sucked from the suction port can be increased.

JP 2004-68644 A JP 2002-371996 A

  In the fan casing described in Patent Document 2, the amount of gas suction at the suction port is increased as compared with that described in Patent Document 1. However, in the fan casing described in Patent Document 2, since the fixed blade only guides and flows the gas in the rotation direction of the impeller, the gas flowing in front of the suction port gradually rotates while rotating the suction port. It is sucked into the inner wall. Therefore, it is difficult to increase the force for pushing the gas into the suction port (dynamic pressure of the fan), and there is a limit to increasing the static pressure of the fan.

  Further, since the gas is sucked from the suction port along the direction of the rotational axis of the impeller, the sucked gas receives a force directed toward the side away from the front wall in the direction of the rotational axis of the impeller. Then, the gas flows through the flow passage while flowing through the flow passage while maintaining the inertial force directed toward the side away from the front wall in the direction of the rotational axis of the impeller. Therefore, in the blowout flow path, the gas flow rate tends to be higher on the side away from the front wall in the direction of the rotational axis of the impeller than on the side approaching the front wall. When more gas is sucked from the suction port, the difference in the gas flow rate between the side away from the front wall in the direction of the rotational axis of the impeller and the side approaching the front wall is significant in the blowout flow path. Become. For this reason, the pressure loss in the blowout flow path becomes large, and it is difficult to smoothly blow out more gas from the blowout port.

  The present invention has been made paying attention to such a point, and its purpose is to increase the amount of gas sucked at the suction port and increase the force to push the gas into the suction port (dynamic pressure of the fan). In the point which provides the casing for fans which can reduce the pressure loss in a blow-off channel.

In order to achieve this object, the fan casing according to the present invention is characterized in that the casing body that houses the rotationally driven impeller has a suction port for sucking gas along the rotational axis direction of the impeller. An opening is provided in a part in the rotational direction of the impeller between a front wall, a rear wall disposed opposite to the front wall, and an outer periphery of the impeller accommodated by connecting the front wall and the rear wall. A circulating inner wall that forms a flow channel for allowing gas to flow toward the blowout port, and the circulating inner wall has a tongue portion having a minimum distance from the outer periphery of the impeller as a circumferential start end and the flow channel. The continuous portion that continues to the blowout flow path wall that forms the blowout flow path to the blowout outlet is the circulation end, and the flow passage width of the flow channel is sequentially increased from the turn start end to the turn end. In the fan casing,
In the casing body, the gas sucked through the intake opening that opens in a part of the rotation direction of the impeller on the outside of the front wall circulates in the same direction as the rotation direction of the impeller to the suction port. A circumferential flow path that flows toward the end, and an introduction section that is disposed at a terminal portion of the circumferential flow path and introduces the gas that has flowed in the circumferential flow path to the suction port. The blowout passage is formed between a connection wall continuously connected between the outer periphery of the impeller and the blowout flow passage wall and from the tongue portion toward the blowout outlet, and the blowout flow passage wall. In the flow passage, the flow passage portion where the tongue portion and the blowout flow passage wall face each other flows more on the side away from the front wall in the direction of the rotational axis of the impeller than on the side closer to the front wall. The road width is large.

  According to this characteristic configuration, the gas around the suction port is sucked from the suction opening, and the sucked gas is circulated in the same direction as the rotation direction of the impeller by the circulation channel. As a result, the gas sucked from the intake opening is increased in flow velocity by the circulation channel and reaches the suction port. Then, the gas whose flow velocity is increased is positively introduced into the suction port by being given a force along the rotational axis direction of the impeller by the introduction portion. Therefore, the gas whose flow velocity is increased is sucked into the suction port, and the force for pushing the gas into the suction port (dynamic pressure of the fan) can be increased. In addition, since the gas around the suction port is sucked at the suction port while being guided and flowed in the circulation channel, the amount of gas sucked at the suction port can be further increased.

  By providing the intake opening, the circulation channel, and the introduction unit, more gas can be sucked from the suction port, so that the tongue portion and the blowing channel wall flow in the channel portion facing the blowing channel. The side where the gas flow rate is farther from the front wall in the direction of the rotation axis of the impeller is more, and the difference in gas flow rate between the side away from the front wall in the direction of the rotation axis of the impeller and the side approaching the front wall growing. Therefore, according to the present characteristic configuration, the flow path width of the flow path portion where the tongue portion and the blow flow path wall face in the blow-off flow path is closer to the side away from the front wall in the rotational axis direction of the impeller. By making it larger than the side approaching the front wall, the flow path width corresponding to the flow rate difference of the flowing gas can be made in the flow path portion. Therefore, it is possible to reduce the pressure loss when the tongue portion and the blowout flow passage wall pass through the flow passage portions facing each other in the blowout flow passage.

  From the above, the rotational speed of the impeller can be obtained at a low rotational speed and a higher static pressure can be obtained, and the power consumption of the motor that rotates the impeller can be reduced while the static pressure of the fan is increased. In addition, it is possible to reduce the pressure loss in the blowout flow path and to blow out more gas smoothly from the blowout port.

  A further characteristic configuration of the fan casing according to the present invention is such that the facing portion of the tongue portion that faces the blowout flow path wall is spaced from the front wall in the rotational axis direction of the impeller. It exists in the point formed in the inclined shape which leaves | separates with respect to the said blowing flow path wall rather than the side which approaches a front wall.

  According to this characteristic configuration, for example, a simple configuration in which the outlet channel wall is a straight upright wall, and the opposing portion of the tongue portion that faces the outlet channel wall is also formed in an inclined shape. With this configuration, the flow width of the flow path portion where the tongue portion and the blow flow path wall face each other in the blow flow path is closer to the front wall in the direction away from the front wall in the rotational axis direction of the impeller. Can be larger than the side. Furthermore, by making the facing part facing the blowout flow path wall in the tongue part into an inclined shape, the time until the gas that has flowed out to the outer periphery of the impeller hits the tongue part is sequentially increased from the side approaching the front wall. become longer. Therefore, a phase difference is generated in the sound generated when the gas hits the tongue, and the sounds generated by each other interfere with each other, thereby suppressing the generation of noise.

  A further characteristic configuration of the fan casing according to the present invention is that the connecting wall is configured such that a distance between the connecting wall and the outlet passage wall increases as the side approaches the outlet.

  According to this characteristic configuration, the flow path portion between the connection wall and the blow flow path wall in the blow flow path becomes lower in pressure as it approaches the blow outlet, so that the pressure difference is used to make the flow between the connection wall and the blow flow path. The gas can smoothly flow through the channel portion between the channel walls.

Perspective view of the casing body as seen from the front side Perspective view of the casing body viewed from the rear side Sectional view of the casing body taken longitudinally along the rotational axis direction of the impeller The figure which shows the casing body seen from the front side The figure which shows the casing body seen from the back side in the state where the back wall was removed The figure which shows the casing main body seen from the back side in the state which removed the rear wall and the impeller Side view of the casing body viewed from the direction in which the air outlet opens Perspective view of the casing body as seen from the front side Perspective view of the casing body viewed from the rear side The figure which shows the casing main body seen from the back side in the state which removed the rear wall and the impeller The figure which shows the casing main body seen from the back side in the state which removed the rear wall and the impeller

An embodiment of a fan provided with a fan casing according to the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 6, the fan 1 includes an impeller 2 that is rotationally driven by a motor (not shown), and a casing body that accommodates the impeller 2 by forming a suction port 3 and an outlet 4. 5. The suction port 3 opens along the rotational axis direction X of the impeller 2 (hereinafter simply referred to as “rotational axis direction X”), and the blowout port 4 rotates in the rotational direction Y of the impeller 2 (hereinafter referred to as “rotational axis direction X”). , Simply abbreviated as rotation direction Y). The impeller 2 is provided with a plurality of blades 2a arranged side by side on the periphery, and is a suction plate having one end opened in the rotational axis direction X and a bottom plate closed at the other end. The impeller 2 is housed in the housing space in such a manner that the suction portion faces the front wall 8 of the casing body 5 and the bottom plate faces the rear wall 13 of the casing body 5. Thereby, the air sucked from the suction port 3 is taken into the impeller 2 through the suction portion of the impeller 2, and the air inside the impeller 2 is centrifugally driven by the blades 2a by the rotational drive and the bottom plate of the impeller 2. It is configured to be leaked.

  The fan 1 sucks air (gas) from the suction port 3 along the rotational axis direction X, and causes the sucked air to flow out in the centrifugal direction from the inside of the impeller 2 to the outer periphery. The centrifugal fan is blown out from the outlet 4. For example, such a fan 1 is used as a fan for a ventilation fan.

  The fan casing according to the present invention is configured by a casing body 5 formed in a rectangular parallelepiped, and the casing body 5 includes an intake side forming portion 6 that forms an intake structure for sucking air at the suction port 3. A blow-out side forming portion 7 that forms a blow-out structure for blowing out air sucked in from the blow-out opening 3 from the blow-out opening 4 is provided. In the casing body 5, the suction side forming portion 6 is formed in front of the front wall 8 (left side in FIGS. 1 to 3) with respect to the front wall 8 in which the air inlet 4 is formed in the rotation axis direction X. The blowing side forming portion 7 is formed on the rear side (right side in FIGS. 1 to 3) of the front wall 8.

  FIG. 1 mainly shows the suction side forming part 6, shows an exploded perspective view of the casing body 5 as seen from the front side of the suction port 3, and FIG. 2 mainly shows the outlet side forming part 7. The exploded perspective view of casing body 5 seen from the back side of inlet 3 is shown. FIG. 3 shows a cross-sectional view of the casing body 5 as viewed from the side when the casing body 5 is longitudinally cut along the rotational axis direction X. 4 is a view showing the casing body 5 as seen from the front side of the suction port 3, and FIG. 5 is a view showing the casing body 5 as seen from the rear side of the suction port 3 with the rear wall 13 removed. FIG. 6 is a view showing the casing body 5 as seen from the rear side of the suction port 3 with the rear wall 13 and the impeller 2 removed.

(Suction side forming part)
The suction side forming part 6 is integrally formed on the outer side (front side) from the outer wall of the front wall 8. The suction side forming portion 6 is caused to flow in the suction passage 9 for sucking air, the circulation passage 10 for flowing the air sucked in the suction opening 9 toward the suction port 3, and the circulation passage 10. And an introduction portion 11 for introducing the air into the suction port 3.

The intake opening 9 opens to a part of the rotation direction Y (the left side in FIG. 4) outside the front wall 8, and is disposed outside the suction port 3 in the radial direction of the impeller 2.
The circulation channel 10 is formed in a spiral shape that circulates the air taken in through the intake opening 9 in the same direction as the rotation direction Y and flows toward the suction port 3. And the circulation channel | path 10 becomes a shape which approaches the suction inlet 3 fundamentally, and the flow path width is comprised narrowly, so that the side which approaches the suction inlet 3 is approached. The circumferential flow path 10 is formed between the circumferential flow path walls 12 erected on the outer side (front side) from the front wall 8, and the side away from the front wall 8 in the rotational axis direction X is open. Thereby, air can be sucked along the rotational axis direction X even in the middle of the circulation flow path 10, and a larger amount of air can be flowed to the suction port 3.

  The introduction part 11 is disposed at the terminal part of the circulation channel 10 and introduces the air that has flowed in the circulation channel 10 into the suction port 3. The introduction portion 11 is continuous from the opening end portion of the suction port 3 continuously to the circumferential flow channel wall 12 positioned on the radially outer side of the suction port 3 among the pair of circumferential flow channel walls 12 forming the circumferential flow channel 10. It is formed in the shape of a wall extending on the side, and its tip extends to the vicinity of the center of the suction port 3. The introduction part 11 is formed in a curved shape along the rotation direction Y from the distal end side toward the proximal end side. As a result, the introduction part 11 applies a force along the rotational axis direction X to the air that has flowed in the circulation channel 10 to positively introduce the air into the circulation channel 10. The air thus flowed is introduced into the suction port 3.

  As described above, the casing body 5 of the fan casing according to the present invention includes the intake opening 9, the circulation channel 10, and the introduction unit 11, so that the air sucked through the intake opening 9 can be supplied to the circulation channel 10. And the flow velocity of the air in the rotational direction Y can be increased to flow into the suction port 3. And since the air which flowed in the circulation channel 10 is given the force along the rotation axis direction X by the introduction part 11 and is actively flowed to the suction port 3 side, the air in the suction port 3 While increasing the amount of suction, air with an increased flow rate can be pushed into the suction port 3. Thereby, when blowing out the flow volume of the same air from the blower outlet 4, even if it does not set the rotational speed of the impeller 2 to a high rotational speed, the force which pushes more air into the suction inlet 3 can be inhaled, The power consumption of the motor can be reduced. As a result, for example, the fan 1 that can achieve a high static pressure (for example, 200 to 300 Pa) and a high flow rate (for example, 100 m <3> / h) can be configured.

[Blow-off side forming part]
The blow-out side forming portion 7 is connected between the rear wall 13 opposed to the front wall 8 and the outer periphery of the impeller 2 housed in the casing body 5 by connecting the front wall 8 and the rear wall 13. And a circulating inner wall 15 for forming a flow passage 14 for allowing air to flow toward the bottom.
The rear wall 13 is formed separately from the front wall 8 in a plate shape, and an accommodation space for accommodating the impeller 2 between the front wall 8 and the rear wall 13 is formed. The impeller 2 accommodated in the accommodating space has the rotation axis of the impeller 2 and the center of the suction port 3 aligned with each other, and is separated from the bell mouth portion 19 of the suction port 3 by a set distance (for example, 2 mm). Has been placed.

  The circling inner wall 15 is composed of a straight standing wall integrally formed on the inner side (rear side) of the front wall 8 and surrounds the outer periphery of the impeller 2 accommodated in the accommodating space. A flow channel 14 is formed between the outer periphery. As shown in FIG. 5, the inner circumferential wall 15 is formed in a shape that draws an enlarged curve (for example, an involute curve) that sequentially increases the flow path width of the flow channel 14 from the circulation start end S <b> 1 toward the circulation end S <b> 2. Then, the circulating inner wall 15 forms the blowing passage 17 to the outlet 4 continuously from the flow passage 14 with the tongue portion 16 having the smallest distance from the outer periphery of the impeller 2 as the starting end S1. A continuous portion R continuing to the blowout flow path wall 18 is defined as a circulation end S2.

(Convex)
In this fan 1, the inner wall of the front wall 8 is formed in a flat shape. However, as shown in FIGS. 3 and 6, the inner wall of the front wall 8 is interposed between the suction port 3 and the rotating inner wall 15 (see FIG. On the right side in FIG.
The convex portion 20 extends in the rotation direction Y from the protrusion start end T1 to the protrusion end T2, and is not disposed over the entire circumference of the rotation direction Y, and a part of the rotation direction Y is opened. . And the convex part 20 makes the downstream side of the rotation direction Y the protrusion start end T1 rather than the tangent L1 of the circular shaped suction inlet 3 which passes the tongue part 16 toward the rotation direction Y, and the suction inlet 3 and the convex part 20 A permissible position that allows the air flowing between the two to flow toward the air outlet 4 is defined as a projecting end T2. The protrusion start end T1 of the protrusion 20 is downstream of the tangent L1 in the rotation direction Y, and a straight line L2 connecting the rotation end S2 of the rotation inner wall 15 and the center P of the suction port 3 and the protrusion start end T1 of the protrusion 20. And an angle α formed by a straight line L3 connecting the center P of the suction port 3 is disposed at a position where the angle α is not less than 0 degrees and not more than 90 degrees. The protruding end T2 of the convex portion 20 is disposed with the circumferential end S2 of the circumferential inner wall 15 as an allowable position. Moreover, the convex part 20 is formed in the shape which draws the expansion curve (for example, involute curve) located in the radial direction outer side of the impeller 2 toward the protrusion termination | terminus T2 from the protrusion start end T1. Thereby, the distance (distance in the radial direction of the impeller 2) between the suction port 3 and the convex portion 20 is configured such that the protruding end T2 side of the convex portion 20 is larger than the protruding start end T1 side. .

  By providing such a convex portion 20, air flowing between the suction port 3 and the convex portion 20 is blown out while preventing a back flow to the suction port 3 even when the pressure of the flow passage 14 increases. The flow can be positively made to flow in the flow path 17, and the air can be made to flow toward the outlet 4 through the blow-out flow path 17. Moreover, since the convex portion 20 does not exist in the tongue portion 16 and the region adjacent to the upstream side in the rotational direction Y from the tongue portion 16, the presence of the convex portion 20 prevents further increase in the pressure of the flow passage 14. Thus, it is possible to prevent the backflow to the suction port 3 from being easily generated. Further, the distance between the suction port 3 and the convex portion 20 (the distance in the radial direction of the impeller 2) is larger on the protruding end T2 side of the convex portion 20 than on the protruding start end T1 side. The pressure difference is utilized not only for the air flowing between the protrusion 20 and the convex portion 20, but also for the tongue 16 adjacent to the protrusion start end T1 and the air that has flowed out to the region adjacent to the upstream side in the rotational direction Y. Thus, it is possible to positively flow through the space between the suction port 3 and the convex portion 20 toward the protruding end T2 of the convex portion 20. Therefore, the air flowing between the suction port 3 and the convex portion 20 is effectively prevented while preventing the backflow to the suction port 3 in the region adjacent to the tongue portion 16 and the upstream side in the rotational direction Y. It can be made to flow toward the blower outlet 4.

(Blowout channel)
In this fan 1, as shown in FIG. 5, the blowout flow path 17 is formed continuously with the flow flow path 14, and is formed in a straight line shape from the end portion of the flow flow path 14 toward the blowout outlet 4. Yes. The blowout flow path 17 is continuously connected between the outer periphery of the impeller 2 and the blowout flow path wall 18, and is connected to the connection wall 21 and the blowout flow path wall 18 connected from the tongue portion 16 toward the blowout port 4. Is formed between.

  As shown in FIG. 7, the blowout flow path wall 18 is formed continuously with the circulating inner wall 15, and is configured by a straight standing wall like the rotating inner wall 15. On the other hand, the facing portion 16a facing the blowout flow path wall 18 in the tongue portion 16 is closer to the front wall 8 on the side away from the front wall 8 in the rotational axis direction X (lower side in FIG. 6). It is formed in an inclined shape that is farther from the outlet flow path wall 18 than the side. FIG. 7 shows a side surface portion of the casing body 5 when the inner side of the casing body 5 is viewed from the direction in which the air outlet 4 opens. As a result, the flow path portion where the tongue portion 16 and the blow flow path wall 18 face each other in the blow flow path 17 is closer to the front wall 8 on the side away from the front wall 8 in the rotational axis direction X. Also, the channel width is large. Further, as shown in FIGS. 5 and 6, the connecting wall 21 is formed in an inclined shape in which the distance from the blowing channel wall 18 increases toward the side closer to the blowing port 4.

  Since the casing body 5 of the fan casing according to the present invention is provided with such a blowout flow path 17, a large amount of air is flowed to the side away from the side approaching the front wall 8 in the rotational axis direction X. In addition, the flow path width of the blowout flow path 17 according to the flow rate difference of the air can be set, and the air can flow while reducing the pressure loss. Moreover, as described above, since a large amount of air can be sucked from the suction port 3 by the circulation channel 10 and the introduction portion 11, a larger amount of air is provided on the side away from the side approaching the front wall 8 in the rotational axis direction X. However, even a larger amount of air can smoothly flow through the blowout flow path 17 and be led to the blowout port 4. And since the distance between the connection wall 21 and the blowing flow path wall 18 is so large that it approaches the blower outlet 4, the air which flows through the blower flow path 17 can be actively guide | induced to the blower outlet 4. FIG. it can. Further, since the tongue portion 16 is formed in an inclined shape, the time until the air that has flowed out to the outer periphery of the impeller 2 hits the tongue portion 16 is gradually increased from the side approaching the front wall 8 to the side away from it. Therefore, a phase difference is generated in the sound generated when air hits the tongue portion 16, and the sounds generated by each other interfere with each other, thereby suppressing the generation of noise.

〔the flow of air〕
As shown by the arrows in FIG. 1 and FIG. 8, the air taken in through the intake opening 9 is swirled in the circulation channel 10 to reach the introduction part 11, and the introduction part 11 sucks the suction port 3. To be introduced. As shown by the arrows in FIGS. 2 and 9, the air introduced into the suction port 3 flows in the flow channel 14 along the rotation direction Y and flows toward the outlet 4 through the outlet channel 17. And blown out from the outlet 4.
Here, since air is blown out from the blower outlet 4 through the blowout flow path 17, more air is supplied from the suction port 3 in the vicinity of the region adjacent to the upstream side in the rotational direction Y with respect to the location of the blowout flow path 17. Will be sucked. Therefore, the introduction portion 11 is disposed in the vicinity of the region adjacent to the upstream side in the rotation direction Y with respect to the location where the blowout flow path 17 is disposed, and is disposed in a region where a large amount of air is sucked from the suction port 3. Has been. For example, as shown in FIG. 10, the introduction portion 11 includes a straight line L4 connecting the tongue portion 16 and the center P of the suction port 3 and the arrangement position of the introduction portion 11 (the center position of the introduction portion 11 in the rotation direction Y). An angle β formed by a straight line L5 connecting the center P of the suction port 3 is disposed at a position where the angle β is not less than 0 degrees and not more than 90 degrees.

(Partition section)
As described above, air flows through the circulation channel 10 outside the front wall 8, and air flows due to the rotational drive of the impeller 2 inside the front wall 8. Therefore, as shown in FIGS. 4 and 6, a partition 22 is provided in the suction port 3 to partition the air flow inside the front wall 8 and the air flow outside the front wall 8. The partition part 22 is configured in a plate shape extending inward from the opening end of the suction port 3. And the partition part 22 is arrange | positioned on the opposite side of the introducing | transducing part 11 and the rotation direction Y. FIG. As a result, the outside and the inside of the front wall 8 are communicated with each other through the suction port 3, but the suction port 3 is connected to the front wall by the partition portion 22 at a place away from the place where the introduction part 11 is disposed in the rotation direction Y. 8 and the inside of the front wall 8 can be divided. Therefore, the partition part 22 can prevent the air flowing in the circulation channel 10 from being short-circuited in the middle and being sucked from the suction port 3. On the contrary, it is possible to prevent the air inside the front wall 8 from flowing back to the outside of the front wall 8 through the suction port 3 by the partition portion 22. The flow of air in the rotational direction Y by the circumferential flow path 10 outside the front wall 8 and the flow of air in the rotational direction Y by the rotational drive of the impeller 2 inside the front wall 8 are separated from each other. It can be suppressed by the portion 22. Therefore, a larger amount of air can be sucked in at the suction port 3, and the air sucked in at the suction port 3 can be efficiently flowed to the flow channel 14 by the rotational drive of the impeller 2. Air can be flowed toward the outlet 4.

As shown in FIG. 11, on the side facing the inner side of the front wall 8 of the partition portion 22, the first negative pressure region 23 is located on the downstream side in the air flow direction toward the air outlet 4 (on the downstream side in the rotational direction Y). The first negative pressure region forming part 24 is formed. For example, on the upstream side in the air flow direction toward the outlet 4 with respect to the partition portion 22 when air collides with the partition portion 22 (a region adjacent to the downstream side in the rotational direction Y with respect to the partition portion 22). A vortex flow W1 may occur. Since the first negative pressure region 23 is formed in the first negative pressure region forming part 24, air can be actively flowed into the first negative pressure region 23 using the negative pressure. Thereby, generation | occurrence | production of the vortex | eddy_current W1 can be suppressed and it can prevent that air stops flowing smoothly by the vortex | eddy_current W1.
Moreover, the partition part 22 is formed in the shape extended from the arrangement | positioning location of the 1st negative pressure area | region formation part 24 to the downstream of the flow direction of the air which goes to the blower outlet 4 (downstream side of the rotation direction Y). As a result, the air that has flowed to the first negative pressure region 23 flows toward the outlet 4 while being guided by the partition portion 22, and the air can smoothly flow toward the outlet 4. it can.

[Second negative pressure region forming section]
As shown in FIG. 11, on the side facing the inner side of the front wall 8 of the introduction portion 11, the second negative pressure region 25 is located downstream in the flow direction of air toward the blowout port 4 (downstream in the rotational direction Y). The second negative pressure region forming part 26 is formed. Similarly to the first negative pressure region forming unit 24 described above, the second negative pressure region forming unit 26 is also downstream of the air flow direction toward the outlet 4 with respect to the introduction unit 11 (relative to the introduction unit 11). Even if there is a possibility that a vortex W2 may be generated in a region adjacent to the downstream side in the rotation direction Y), the vortex W2 is generated by positively flowing air to the second negative pressure region 25 using negative pressure. Is suppressed, and the vortex W2 prevents the air from flowing smoothly.

[Another embodiment]
(1) In the above embodiment, the introduction part 11 is configured by a straight standing wall. For example, the introduction part 11 is closer to the inlet 3 in the rotational axis direction X of the impeller 2. It can also be constituted by an inclined wall having a narrow width. In this case, a larger force can be applied to the air flowing in the circulation channel 10 on the side approaching the suction port 3 in the rotational axis direction X of the impeller 2, and the air is pushed into the suction port 3. The power can be further improved.

(2) In the above-described embodiment, the blowing channel wall 18 is configured with a straight upstanding wall and a portion facing the tongue 16 and a portion facing the connecting wall 21 continuously, for example, The side away from the front wall 8 in the rotational axis direction X of the impeller 2 can be formed so as to be inclined away from the tongue 16 and the connecting wall 21 than the side approaching the front wall 8.

  In the present invention, the casing body includes a front wall having a suction port for sucking gas along the direction of the rotation axis of the impeller, a rear wall disposed opposite to the front wall, the front wall, and the rear wall. A circumferential inner wall that forms a flow passage for allowing gas to flow toward a blowout opening that opens in a part of the rotation direction of the impeller between the outer periphery of the impeller that is connected and accommodated; It can be applied to various fan casings that can reduce the pressure loss in the blowout flow path while increasing the force to push the gas into the suction port (dynamic pressure of the fan) by increasing the amount of gas suction is there.

DESCRIPTION OF SYMBOLS 1 Fan 2 Impeller 3 Intake port 4 Outlet 5 Casing main body 8 Front wall 9 Intake opening part 10 Circulation flow path 11 Introduction part 13 Rear wall 14 Flow path 15 Circulation inner wall 16 Tongue part 16a Opposing part 17 Blowout flow path 18 Blowout Channel wall 21 Connecting wall

Claims (3)

A casing body that accommodates a rotationally driven impeller includes a front wall having a suction port for sucking gas along the direction of the rotational axis of the impeller, a rear wall disposed opposite to the front wall, and the front wall, A circulating inner wall that forms a flow channel that allows gas to flow toward a blowout opening that opens in a part of the rotation direction of the impeller between the rear wall and the outer periphery of the impeller accommodated. Prepared,
The inner circumferential wall is continuous with a blowout channel wall that forms a blowout channel to the blower outlet, with a tongue portion having a minimum distance from the outer periphery of the impeller as a circumferential start end. A fan casing in which a continuous portion is a circulation end, and the flow passage width of the flow channel is sequentially increased from the circulation start end toward the circulation end,
In the casing body, the gas sucked through the intake opening that opens in a part of the rotation direction of the impeller on the outside of the front wall circulates in the same direction as the rotation direction of the impeller to the suction port. A circulation channel that flows toward the end, and an introduction unit that is disposed at a terminal portion of the circulation channel and introduces the gas that has flowed in the circulation channel to the suction port,
The blowing channel is continuously between the outer periphery of the impeller and the blowing channel wall, and is connected between the connecting wall connected from the tongue portion toward the outlet and the blowing channel wall. Formed,
In the blowout flow path, the flow path portion where the tongue portion and the blowout flow path wall face each other is closer to the front wall on the side away from the front wall in the rotational axis direction of the impeller. The fan casing has a large flow path width.   The facing portion of the tongue that faces the blowing channel wall is closer to the blowing channel wall on the side away from the front wall in the rotational axis direction of the impeller than on the side approaching the front wall. The fan casing according to claim 1, wherein the fan casing is formed in an inclined shape that is separated from the fan casing.   3. The fan casing according to claim 1, wherein the connecting wall is configured such that a distance between the connecting wall and the outlet channel wall increases as the side approaches the outlet.

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