JP2011226398A - Electric blower and electric vacuum cleaner mounted with the same - Google Patents

Abstract

An object of the present invention is to suppress the non-uniform flow of air from the shroud to the hub, and to match the flow with a stationary blade installed downstream of the rotating blade, thereby reducing the internal loss of the rotating blade and Reduces delamination loss inside stationary blades.
A vane 500 has a shroud shape 501 of the vane 500 in the vicinity of the entrance 503, and the shroud shape 501 of the vane 500 is inclined in the rotation direction 505, and the inclination of the shroud shape 501 is close to the hub side shape 502. The shroud-side shape 501 of the blade 500 is inclined in the counter-rotation direction when moving toward the outer edge of the blade, and further toward the outer edge portion, the inclination in the counter-rotation direction becomes smaller as the outer edge is approached. The blade has a substantially two-dimensional shape near the portion, and when viewed from the axial direction, the blade has two substantially two-dimensional shapes from the inner edge to the outer edge, and has a shape in which the tilting rotation direction changes before and after the two.
[Selection] Figure 5

Description

  The present invention relates to an electric blower including a fan blade having a shape twisted between an inner edge and an outer edge, and a vacuum cleaner equipped with the electric blower.

  A conventional electric blower is also shown in, for example, Patent Document 1 below, and generally includes a shroud, a main plate disposed at an opposing position thereof, and a plurality of blades disposed therebetween. The blade has a shroud side inclined more than the hub side and rotated at a high speed to obtain an air volume and a vacuum pressure.

  In particular, in Patent Document 1, a fan blade is sandwiched between a front shroud and a rear shroud (hub) and fixed by caulking. When comparing the radius of curvature of the fan blade near the inlet, the front shroud side is A rotating fan of an electric blower is described in which the front shroud side is inclined in the rotational direction on the inner peripheral side and tilted in the rotational direction on the inner peripheral side by tilting larger than the rear shroud side.

  Moreover, the structure of the conventional fan similar to the conventional electric blower is shown by the following patent document 2, for example. The conventional fan has a plurality of blades straddling between the outer peripheral portions of the hub and the shroud, and has a fan suction port formed in the central portion of the shroud, and a shroud side coupling portion at the rear edge portion of each blade The centrifugal fan impeller is offset by a predetermined amount in the counter-rotating direction from the position at the hub side coupling portion, and the hub side blade outlet angle and the shroud side blade outlet angle at the trailing edge of each blade A centrifugal fan impeller characterized by equalization is described.

Japanese Patent No. 2757501 (Japanese Patent Laid-Open No. 3-151598) Japanese Patent No. 2730396 (Japanese Patent Laid-Open No. 4-120753)

  In the conventional electric blower (Patent Document 1), since detailed blade angle distribution is not adjusted with respect to the air flow at the inlet, separation and backflow are likely to occur in the flow inside the impeller, resulting in energy loss (decrease in efficiency). Cause. In particular, at the suction port of the electric blower, the leakage flow generated by the pressure difference between the blade suction port and the impeller outlet is suppressed by a rotating blower and a mouth ring for guiding the suction flow. For this reason, there is a step at the connection between the rotating body and the stationary body at the suction port, and in consideration of this step flow and leakage flow, in order to match the blade inlet angle and adjust the blade load distribution, It was necessary to understand the phenomenon and optimize the whole. That is, by adjusting the blade angle distribution by matching with the leakage in the presence of the inlet leakage, it is necessary to optimize the blade load distribution, suppress separation and backflow, and achieve high efficiency. In addition, since the fan blade angle distribution is not adjusted in detail with respect to the air flow at the inlet, the inclination of the impeller blades does not coincide with the inflow direction of the air near the suction port, and the air is on the side surface of the fan blades. In this case, the collision loss may increase.

  Further, in the electric blower (Patent Document 1), when viewed from the axial direction, the blade has a large inclination with respect to the main plate, so that the blade and the caulking are easily crushed by buckling or the like in the process of assembling with the sheet metal. There was the above problem.

  Further, in the conventional electric blower (Patent Document 1), the outer peripheral side (outflow side) is substantially perpendicular to the rear shroud even though the front shroud side is inclined in the rotational direction on the inner peripheral side (inflow side). Therefore, on the outer peripheral side (outflow side), the air flow from the front shroud to the rear shroud becomes non-uniform, that is, the pressure distribution and velocity distribution from the front shroud to the rear shroud become non-uniform, resulting in increased energy loss. There is.

  Further, in the conventional fan (Patent Document 2), when a stationary blade (for example, a diffuser) installed to efficiently decelerate the flow out of the fan is formed downstream of the fan, the shroud side at the trailing edge of the blade In centrifugal fan impellers where the position of the coupling part is offset by a predetermined amount in the counter-rotating direction from the position at the hub side coupling part, the flow cannot be matched with the stationary blades. Peeling and backflow are likely to occur, causing energy loss (decrease in efficiency).

  Therefore, the present invention can optimize the shape of the blade in each cross section in the rotation axis direction, can suppress the separation and backflow of the flow in the flow path between the blades, or can reduce the average flow velocity of the flow at the blade outlet, or An object of the present invention is to provide a highly efficient electric blower and a vacuum cleaner equipped with the electric blower, which can suppress uneven flow velocity distribution from the shroud to the hub at the blade outlet.

  Another object of the present invention is to provide an electric blower that suppresses the buckling of the blade when the blade is caulked and attached to the hub and the shroud, and a vacuum cleaner equipped with the electric blower.

  In the present invention, each blade is twisted from the state of being twisted toward the rotational direction with respect to the rotational axis direction from the radially inner edge to the radially outer edge, and then twisted toward the rotational direction. It is characterized by being able to.

  Alternatively, according to the present invention, in each blade, the formation direction of the rotation axis direction from the connection portion with the hub to the connection portion with the shroud is substantially coincident with the rotation axis direction or the rotation axis direction at the radially outer edge portion of the blade. The blades are inclined to the rotational direction side with respect to the reference, and the direction of the rotational axis of each blade is the portion inclined to the rotational direction side with respect to the rotational axis direction in the radial direction intermediate portion of the blade and the rotational axis direction. And a portion inclined toward the counter-rotating direction.

  Alternatively, according to the present invention, when viewed from the rotation axis direction, the hub-side camber line at the connection portion of the blade with the hub and the shroud-side camber line at the connection portion of the blade with the shroud are arranged from the radially inner edge to the radially outer edge. Crossing at least at two places.

  Alternatively, if the angle between the perpendicular line to the straight line connecting the arbitrary position of the blade and the axis of the rotating shaft and the tangent line on the outer surface of the blade viewed from the rotating shaft direction is defined as the blade angle, the blade hub side The blade angle is smaller than the blade angle on the shroud side of the blade, particularly at the radially outer edge.

  According to the present invention, each blade is twisted from the state twisted in the rotational direction with respect to the rotational axis direction to the counter rotational direction side from the radially inner edge to the radially outer edge, and then again in the rotational direction side. By being twisted, the shape of the blade in each cross section in the rotation axis direction is optimized, and flow separation and backflow in the passage between the blades can be suppressed. Moreover, the average flow velocity of the flow at the blade outlet can be reduced. Moreover, it can suppress that the flow velocity distribution from the shroud at the blade outlet to the hub becomes non-uniform. Thereby, the efficiency of an electric blower can be improved and the suction work rate of an electric blower and a vacuum cleaner carrying it can also be improved.

  According to the present invention, each blade has a rotational axis direction formed from a connecting portion with the hub to a connecting portion with the shroud substantially coincides with the rotating shaft direction or the rotating shaft direction at the radially outer edge portion of the blade. The blades are inclined to the rotational direction side with respect to the reference, and the direction of the rotational axis of each blade is the portion inclined to the rotational direction side with respect to the rotational axis direction in the radial direction intermediate portion of the blade and the rotational axis direction. On the other hand, the shape of the blade in each cross section in the rotation axis direction is optimized, and flow separation and backflow in the flow path between the blades can be suppressed. Moreover, the average flow velocity of the flow at the blade outlet can be reduced. Moreover, it can suppress that the flow velocity distribution from the shroud at the blade outlet to the hub becomes non-uniform. Thereby, the efficiency of an electric blower can be improved and the suction work rate of an electric blower and a vacuum cleaner carrying it can also be improved.

  According to the present invention, when viewed from the rotation axis direction, the hub-side camber line at the connecting portion of the blade with the hub and the shroud-side camber line at the connecting portion of the blade with the shroud are arranged from the radially inner edge to the radially outer edge. By crossing at least two points, the blades can be prevented from buckling by caulking at the intersecting portion when the blades are caulked and attached to the hub and the shroud. Furthermore, the shape of the blade | wing in each cross section of a rotating shaft direction is optimized, and the peeling and the backflow of the flow in the flow path between blade | wings can be suppressed. Moreover, the average flow velocity of the flow at the blade outlet can be reduced. Moreover, it can suppress that the flow velocity distribution from the shroud at the blade outlet to the hub becomes non-uniform. Thereby, the efficiency of an electric blower can be improved and the suction work rate of an electric blower and a vacuum cleaner carrying it can also be improved.

  According to the present invention, an angle formed by an orthogonal line to a straight line connecting an arbitrary position of the blade and the axis of the rotating shaft and a tangent line on the outer surface of the blade as viewed from the rotating shaft direction is defined as a blade angle. The blade angle on the hub side of the blade is smaller than the blade angle on the shroud side of the blade, particularly at the radially outer edge, so that the shape of the blade in each cross section in the rotation axis direction is optimized, and the flow in the flow path between the blades Peeling and backflow can be suppressed. Moreover, the average flow velocity of the flow at the blade outlet can be reduced. Moreover, it can suppress that the flow velocity distribution from the shroud at the blade outlet to the hub becomes non-uniform. Thereby, the efficiency of an electric blower can be improved and the suction work rate of an electric blower and a vacuum cleaner carrying it can also be improved.

It is a typical cross-sectional view of a cleaner body. It is sectional drawing of the electric blower for vacuum cleaners. It is a block diagram of the impeller eyeball vicinity. It is a shape figure of an impeller. It is a shape figure of a blade | wing. It is a detailed shape figure of a blade | wing. It is a figure which shows blade | wing installation angle distribution in the shroud and main plate contact surface of a blade | wing. It is a comparison figure of the efficiency of an Example and a comparative example. It is a comparison figure of axial direction distribution of an impeller exit speed of an example and a comparative example. It is a comparison figure of the speed distribution in the axial direction center cross section inside the diffuser of an Example and a comparative example. It is a figure which shows the position of crimping. It is a figure which shows the protrusion of crimping. It is a shape figure of an impeller and a diffuser. It is a shape figure of the blade | wing of a present Example and a comparative example. It is a comparison figure of velocity distribution in each section of axial height inside an impeller of an example and a comparative example.

  The present invention relates to an annular shroud, a hub disposed opposite to the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and an electric part that rotates the shroud, the hub, and the blades. Each blade is formed of a flat plate, and each blade is from the radially inner edge to the radially outer edge and is twisted to the rotational direction side with respect to the rotational axis direction as the counter rotational direction side. And then twisted again in the rotational direction.

  The present invention relates to an annular shroud, a hub disposed opposite to the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and an electric part that rotates the shroud, the hub, and the blades. Each blade is formed of a flat plate, and each blade has a rotational axis direction from the connecting portion with the hub toward the connecting portion with the shroud, at the radially outer edge of the blade, The blades substantially coincide with the rotation axis direction or are inclined toward the rotation direction side with reference to the rotation axis direction, and each blade is formed in the rotation axis direction at the intermediate portion in the radial direction of the blade. It has the part inclined to the side, and the part inclined to the anti-rotation direction side with respect to the rotating shaft direction.

  The present invention relates to an annular shroud, a hub disposed opposite to the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and an electric part that rotates the shroud, the hub, and the blades. Each blade is formed in a flat plate, and when viewed from the direction of the rotation axis, the shroud side camber in the connection portion between the hub-side camber line and the blade shroud in the connection portion between the blade and the hub The line intersects at least two points from the radially inner edge to the radially outer edge.

  The present invention relates to an annular shroud, a hub disposed opposite to the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and an electric part that rotates the shroud, the hub, and the blades. Each blade is formed of a flat plate, and a tangent line on the outer surface of the blade that is curved when viewed from the direction of the rotation axis and an orthogonal line to a straight line connecting an arbitrary position of the blade and the axis of the rotation shaft The blade angle on the hub side of the blade is characterized by being smaller than the blade angle on the shroud side of the blade at the radially inner edge and the radially outer edge.

  ADVANTAGE OF THE INVENTION According to this invention, the shape of the blade | wing in each cross section of a rotating shaft direction is optimized, and the peeling and the backflow of the flow in the flow path between blade | wings can be suppressed. Moreover, the average flow velocity of the flow at the blade outlet can be reduced. Moreover, it can suppress that the flow velocity distribution from the shroud at the blade outlet to the hub becomes non-uniform. Thereby, the efficiency of an electric blower can be improved and the suction work rate of an electric blower and a vacuum cleaner carrying it can also be improved. In addition, according to the present invention, by matching the inlet leakage and the blade angle distribution, the separation phenomenon and the backflow phenomenon in the air flow inside the impeller can be suppressed, and high efficiency can be achieved.

  Further, when the vane is caulked and attached to the hub and the shroud, the vane can be prevented from buckling by caulking at the intersection. Further, according to the present invention, the assembly accuracy can be improved by optimizing the caulking position.

  Further, according to the present invention, at the inner edge of the blade, the blade can be inclined so as to coincide with the inflow direction of the air, the air can be prevented from hitting the side surface of the blade, and the collision loss can be reduced. . In addition, according to the present invention, it is possible to match the flow with the stationary blade installed downstream of the rotating blade, and reduce the loss inside the rotating blade and the separation loss inside the stationary blade. Yes, energy loss can be reduced.

  Embodiments 1 and 2 of the present invention will be described below in detail with reference to the drawings.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, the whole vacuum cleaner will be described with reference to FIG. The configuration of the vacuum cleaner main body 100 will be described with reference to a cross-sectional view seen from above of the vacuum cleaner main body 100 schematically shown in FIG. If the side to which the hose joint 101 of the vacuum cleaner body 100 is attached is the front side of the vacuum cleaner body 100, the vacuum cleaner body 100 includes a detachable hose joint 101 at the front end. A dust collection chamber 102 for holding the paper pack 103 is provided on the front side of the vacuum cleaner main body 100, and a motor chamber 105 for housing the electric blower 106 is provided on the rear side of the vacuum cleaner main body 100. A filter unit 104 is provided between the chamber 102 and the motor chamber 105 to prevent dust in the dust collection chamber 102 from flowing into the motor chamber 105. The dust collection chamber 102 and the motor chamber 105 communicate with each other via the filter unit 104. The dust collection chamber 102 includes a detachable paper pack 103. The opening of the paper pack 103 communicates with the hose joint 101. As dust accumulates in the paper pack 103, the paper pack 103 swells, and the bottom located on the opposite side to the opening of the paper pack 103 comes into contact with the filter unit 104. The motor chamber 105 includes an electric blower 106 that generates a suction force. Anti-vibration rubber 107 (anti-vibration member) for suppressing the vibration of the electric blower 106 from being transmitted to the electric vacuum cleaner main body 100 between the front both ends of the electric blower 106 and the inner wall surface on the front side of the motor chamber 105. Is provided. The vibration isolation member may be a spring instead of rubber. The electric blower 106 includes a blower inlet 108 for sucking air at the front end, and a blower outlet 109 for discharging air on the rear side. The blower inlet 108 is open to the filter unit 104. A cord reel 110 is provided on the side of the motor chamber 105 to wind and store a power cord. Wheels are provided on both sides of the rear side of the electric blower 106. Although not shown, a hose is connected to the hose joint 101, an operation tube for receiving operations such as ON / OFF of the vacuum cleaner main body 100 is connected to the hose, and the operation tube is extendable. An extension pipe is connected, and a suction tool is connected to the extension pipe. The side where the hose joint 101 exists (upstream side) is the front side of the vacuum cleaner body 100, and the opposite side is the rear side of the vacuum cleaner body 100. The hose joint 101, the hose, the operation tube, and the extension tube are not essential components, and an operation unit and a suction tool formed on the operation tube may be directly formed on the electric blower 106. The direction orthogonal to the front-rear direction of the vacuum cleaner body 100 when the vacuum cleaner body 100 is viewed from above is the left-right direction of the vacuum cleaner body 100. The side means a side closer to the left side or the right side than the center of the electric vacuum cleaner main body 100 in the left-right direction. The electric blower 106 may be placed in a horizontal direction in which the blower inlet 108 faces the front side of the electric vacuum cleaner main body 100 (horizontal placement), or the vertical direction in which the blower inlet 108 faces the upper side of the electric vacuum cleaner main body 100. May be placed (vertical).

  Next, the air flow in the vacuum cleaner main body 100 will be described. Air flowing in from the hose joint 101 enters the dust collection chamber 102. In FIG. 1, a paper pack 103 is shown as the dust collecting means, but the material of the pack is not limited. In the case of the cyclone method, a cyclone chamber (a cyclone dust collecting case) is accommodated instead of the paper pack 103. The air from which most of the dust has been removed by the paper pack 103 further passes through the filter unit 104, but fine dust is also removed here. Thereafter, the air flow flows into the motor chamber 105. The electric blower 106 is suspended in the motor chamber 105 via an anti-vibration rubber 107, and the air flowing from the blower inlet 108 is pressurized by the electric blower 106 and then exhausted from the blower outlet 109.

  Next, the electric blower 106 will be described with reference to FIG. The electric blower 106 includes a blower 201 (fan unit) for sucking air and an electric motor 202 (drive unit) for driving the blower 201.

  In the electric motor 202, a rotating shaft 205 is supported on an electric motor outer shell including a housing 203 and an end bracket 204, and a rotor 206 is attached to the rotating shaft 205. A fixed portion stator 207 is arranged on the outer periphery of the rotor 206. The supply of electricity to the rotor 206 of the rotating part is transmitted by a brush 208 and a commutator 209 that contacts the brush 208.

  The blower 201 includes an impeller 210 directly connected to the rotation shaft 205, a diffuser 211 installed on the outer peripheral side of the impeller 210, and a return guide 213 arranged facing the diffuser 211 with a partition plate 212 interposed therebetween. The fan casing 214 is configured to be accommodated. A plurality of blades (moving blades) are formed on the impeller 210. The diffuser 211 does not rotate because it is not connected to the rotating shaft 205. A plurality of blades (stator blades) are also formed in the diffuser 211. The impeller 210 is substantially in contact with a sealing material 216 provided on the fan casing 214 side in an annular centerpiece 215, and has a structure that prevents air leakage.

  Air that has passed through the electric blower inlet 217 corresponding to the blower inlet 108 in FIG. 1 first passes through the vicinity of the eyeball 215, and then is boosted and accelerated by the impeller 210. Thereafter, the flow passes through the diffuser 211 and turns approximately 180 ° and flows into the return guide 213. In this process, the flow is decelerated and the pressure rises accordingly. The flow that has passed through the return guide 213 flows into the motor housing 203 and cools the rotor 206, the stator 207, the brush 208, the commutator 209, and the like before being exhausted. The axial direction of the rotating shaft 205 substantially coincides with the front-rear direction of the electric vacuum cleaner main body 100. A direction perpendicular to the axial direction with respect to the rotation shaft 205 is a radial direction.

  The outer diameter of the electric fan for the vacuum cleaner targeted by the present invention is in the range of about φ60 mm to φ120 mm, the height of the blade outlet is in the range of about 6 to 12 mm, and the thickness of the blade is about 0.5 to 1. In the range of .5mm, the number of blades is in the range of about 6-9, the input is in the range of about 500W to 1500W, and the maximum speed is in the range of about 35,000 to 50,000 revolutions per minute. .

  Next, the structure in the vicinity of the centerpiece 300 of the electric blower of this embodiment will be described with reference to FIG. FIG. 3 is an enlarged view of the vicinity of the eyeball 215 in FIG. A sealing material 302 corresponding to the sealing material 216 in FIG. 2 is fixed via a sealing material fixing component 301 attached to a fan casing 309 corresponding to the fan casing 214 in FIG. An impeller eyeball 315 bites into the sealing material 302 to form a sealing mechanism. Although it is important that this sealing mechanism is in this position, it is not limited to this method. The vane 306 is fixed to the axially front shroud wall 304 and the axially rear hub wall 305 by caulking 317. However, the blades 306 may be fixed by means other than caulking. The blade 306 is formed of a flat plate made of a material whose main component is aluminum having a substantially uniform thickness. Here, “substantially uniform” includes thickness due to deformation during processing and thermal deformation, and thickness due to surface irregularities. The shroud is constituted by a flat plate made of a material whose main component is aluminum having a substantially uniform thickness, and has an annular shape. That is, the shroud has a circular opening at the center. The side wall surface of the shroud blade 306 is the shroud wall 304. As shown in FIG. 3, the outer edge (radially outermost circumference) of the shroud faces in the radial direction, and the inner edge (radially innermost circumference) of the shroud faces in the axial direction. As shown in FIG. 3, the direction is gradually changed from the radial direction to the axial direction in the vicinity of the inner edge of the shroud. The hub is also composed of a flat plate made of a material whose main component is aluminum having a substantially uniform thickness, and has a circular shape or an annular shape. A hub blade 306 side wall surface is a hub wall 305. As shown in FIG. 3, both the outer edge and the inner edge of the hub are oriented in the radial direction. Therefore, the outer edge of the shroud and the outer edge of the hub are substantially parallel and spaced apart. The blade 306, the shroud, and the hub may be an alloy containing aluminum, a metal other than aluminum (for example, iron, stainless steel, titanium), or ceramics. In general, a plurality of crimps are prepared along both the end surfaces of the blades 306 on the shroud wall 304 side and on the hub wall 305 side. However, here, attention is paid only to the shroud wall 304 side and the innermost diameter side (inner edge side). And illustrated. The caulking 317 is preferably formed integrally with the blade 306. For example, when the blade 306 is die-cut from the flat plate, the caulking 317 can be integrally formed with the blade 306 if the caulking 317 is also die-cut together. Alternatively, the caulking 317 can be integrated with the vane 306 by cutting the vane 306 from the flat plate and cutting the caulking 317 together. The end surface on the shroud wall 304 side of the blade 306 has a shape along the shroud wall 304, and the end surface on the hub wall 305 side of the blade 306 has a shape along the hub wall 305. A line on the shroud wall 304 side end surface of the blade 306 is referred to as a shroud side camber line, and a line on the hub wall 305 side end surface of the blade 306 is referred to as a hub side camber line. An impeller 303 is constituted by a shroud, a hub, and a plurality of circumferentially arranged blades 306. The hub is fixed to a rotation shaft 308 corresponding to the rotation shaft 205 in FIG. 2, and as a result, the impeller 303 is fixed to the rotation shaft 308. As a result, the impeller 303 rotates with the rotation of the rotating shaft 308. The inner edge of the blade 306 protrudes forward and forms a blade leading edge 307. There is a space between the blade leading edge 307 and the rotating shaft 308, and forms a flow path. The position of the stationary portion tip 314 on the inner periphery of the fan casing 309 and the position of the blade leading edge 307 of the blade 306 do not coincide with each other, and the stationary portion leading end 314 is positioned on the front side of the blade leading edge 307 in the axial direction. A step 316 is provided. That is, there is a step in the axial direction between the fixed portion and the rotating portion. The position of the stationary part tip 314 on the inner periphery of the fan casing 309 and the position of the shroud impeller eyeball 315 do not coincide with each other, and the stationary part tip 314 is located on the inner circumference side of the impeller eyeball 315. And a radial step 310. That is, there is a step in the radial direction between the fixed portion and the rotating portion. The thick arrow indicates the air flow direction 313. Air enters the entrance of the eyeball portion 215 and flows into a space (flow path) formed between two circumferentially adjacent blades 306. The presence of the radial step 310 causes a leak in the flow.

  Next, the shape of the impeller 400 will be described with reference to FIG. Fig.4 (a) is the front view which looked at the impeller 400 from the axial direction front side. FIG. 4B is a side view of the impeller 400 viewed from the side perpendicular to the rotation axis. As shown in FIG. 4A, eight blades 401 corresponding to the blades 306 in FIG. 3 are installed at equal intervals in the circumferential direction, and in the rotational direction as they go radially outward from the impeller centerpiece 404. And the anti-rotation direction and once again the shape twisted in the rotation direction. Further, as shown in FIG. 4B, the maximum diameter of the shroud wall 402 installed on the front surface of the blade 401 is larger than the maximum diameter of the hub wall 403 installed on the rear surface of the blade 401. That is, the outer periphery of the shroud is larger than the outer periphery of the hub. Therefore, the outer edge of the shroud is located on the outer peripheral side of the outer edge of the hub. Moreover, the outer edge which the shroud wall 402 and the blade | wing 401 contact is the same diameter, and the outer edge which the hub wall 403 and the blade | wing 401 contact also has the same diameter. Therefore, the shroud side outer edge of the blade 401 is larger than the hub side outer edge.

  Next, the shapes of the impeller 400 and the diffuser 211 will be described with reference to FIG. The diffuser 211 is formed so as to cover the outer peripheral side of the impeller 400. The inner edge of the diffuser 211, which is a stationary body, is positioned with a gap that allows the impeller 400 to rotate with respect to the outer edge of the impeller 400, which is a rotating body. The diffuser 211 is formed by sandwiching a plurality of (for example, 13) blades (static blades) 406 in the circumferential direction between an annular member on the front surface side and an annular member on the bottom surface side. The vanes 406 of the diffuser 211 are not uniform in thickness and are made of a resin material. The blades 401 of the impeller 400 are twisted to have a three-dimensional shape, whereas the blades 406 of the diffuser 211 have a two-dimensional shape because they are merely twisted or curved without being twisted. The number of blades 406 of the diffuser 211 is larger than the number of blades 401 of the impeller 400. The blades 401 of the impeller 400 are inclined or curved from the inner edge to the outer edge in the counter-rotation direction opposite to the rotation direction 405 with respect to the radial direction centered on the axis of the rotation shaft. On the other hand, the blades 406 of the diffuser 211 are inclined or curved toward the rotation direction 405 of the impeller 400 from the inner edge to the outer edge with respect to the radial direction centering on the axis of the rotation shaft. Therefore, when viewed from the axial direction, the inclination / curvature direction of the blade 401 of the impeller 400 is opposite to the inclination / curvature direction of the blade 406 of the diffuser 211, and the outer edge (exit) of the blade 401 of the impeller 400 ) In the axial direction substantially coincides with the axial formation direction of the inner edge (inlet) of the blade 406 of the diffuser 211. For example, when the axial formation direction of the blades 406 of the diffuser 211 is substantially coincident with the axial direction, the axial formation direction of the outer edge of the vane 401 of the impeller 400 is also substantially coincident with the axial direction or in the rotational direction. A slight inclination is preferred. As a result, the flow of air flowing out from the impeller 400 flows smoothly into the diffuser 211 with little disturbance.

  Next, the shape of the blade 500 will be further described with reference to FIG. FIG. 5 is a front view of one blade 500 as viewed from the front side in the axial direction. When viewed in an absolute coordinate space based on the rotation axis direction, the formation direction of the rotation axis direction from the hub wall to the shroud wall of the blade 500 is inclined in the rotation direction 505 in the vicinity of the inlet 503 including the inner edge, and the outer edge of the blade Toward the rotation direction, the inclination in the rotation direction decreases, and substantially coincides with the rotation axis direction to form a substantially two-dimensional shape 506. Further, the direction of formation of the rotation axis direction from the hub wall to the shroud wall of the blade 500 is inclined in the counter-rotation direction rather than the rotation axis direction toward the outer edge of the blade, and after reaching the maximum inclination in the counter-rotation direction. As the outer edge is further approached, the inclination in the counter-rotation direction becomes smaller, and substantially coincides with the rotation axis direction in the vicinity of the exit 504 to become a substantially two-dimensional shape 507. The formation direction of the rotation axis direction from the hub wall to the shroud wall of the blade 500 is further slightly inclined (about several degrees) in the rotation direction again at the outer edge portion. That is, when viewed from the axial direction, the blade 500 is twisted in the counter-rotating direction from the state twisted in the rotating direction from the inner edge to the outer edge, and then twisted again in the rotating direction. When viewed from the axial direction, the blade 500 has two substantially two-dimensional shapes 506 and 507 from the inner edge to the outer edge, and has a shape in which the inclination direction changes before and after the two. Here, the substantially two-dimensional shape means that it is in a plane including the rotation axis direction. Specifically, the connection portion between the shroud wall of the blade 500 and the connection portion between the hub wall of the blade 500 and the rotation shaft. It exists in the direction. The entrance end of the entrance vicinity 503 is an inner edge in the radial direction and a front edge in the circumferential direction (the foremost end in the rotation direction 505). The exit end in the vicinity of the exit 504 is an outer edge in the radial direction and a rear edge (the last end in the rotation direction 505) in the circumferential direction. In other words, the vicinity of the inlet 503 and the vicinity of the outlet 504 are inclined in the rotational direction, but the inner edge and the outer edge have two substantially two-dimensional shapes, and the inclination direction changes before and after the substantially two-dimensional shape. ing. The blade 500 is formed by bending a flat plate, and the thickness of the blade 500 is not particularly thick at the middle portion but is substantially uniform. The inclination from the end surface of the hub side 502 to the end surface of the shroud 501 at the intermediate portion of the blade 500 may be linear or curved (may be warped). The formation direction of the rotation axis direction from the hub wall to the shroud wall of the blade 500 may substantially coincide with the rotation axis direction at the outer edge portion. The direction of formation of the rotation axis direction of the blade 500 at the inner edge portion depends on the incident angle of air to the blade 500. The formation direction of the rotation axis direction of the blades 500 at the outer edge portion depends on matching with the incident angle of air to the diffuser 211. Therefore, it is preferable that the formation direction in the rotation axis direction of the blade 500 at the outer edge portion substantially coincides with the formation direction in the rotation axis direction of the blade 406 of the diffuser 211.

  When viewed in a relative coordinate space based on the shape of the hub side 502 (hub side camber line), the shape of the shroud side 501 (the shroud side camber line) with respect to the shape of the hub side 502 is formed on the inner edge side in the radially intermediate portion. ) Is curved in the rotational direction, and the shape of the shroud side 501 is curved in the counter-rotating direction with respect to the shape of the hub side 502 on the outer edge side in the radially intermediate portion, and the shape of the hub side 502 is curved in the vicinity of the outlet 504. On the other hand, the shape of the shroud side 501 slightly protrudes in the rotation direction. That is, the position of the connection portion with the shroud wall with respect to the connection portion with the hub wall of the blade 500 is on the anti-rotation direction side on the outer edge side in the radially intermediate portion, and further on the outer edge portion, The position of the connection portion with the shroud wall with respect to the connection portion with the hub wall of the blade 500 is on the rotational direction side with respect to the connection portion with the hub wall of the blade 500 rather than the outer edge side located on the inner peripheral side with respect to the outer edge portion. As a result, from the inner edge to the outer edge of the blade 500, the shape of the hub side 502 (hub side camber line) and the shape of the shroud side 501 (shroud side camber line) intersect at two places.

  Next, a specific shape of the blade 601 will be described with reference to FIG. FIG. 6 is a front view of the impeller 600 viewed from the front side in the axial direction, and shows only one blade 601 that is installed as a representative. Note that R1 to R7 in FIG. 6 are circles that are concentric with the diameter of the eyeball centered on the rotation axis, and each axis intersects each point where the shape of the shroud side 602 and the shape of the hub side 603 intersect. Let the angle formed by be the inclination angle θ. It can be said that the inclination angle θ is an inclination angle of the impeller 600 in the circumferential direction with respect to the axial direction. The inclination angle θ is positive when the shroud-side shape is inclined in the rotational direction and negative when it is inclined in the counter-rotating direction. The blade 601 has the same diameter R1 (inner edge) as the eyeball diameter, and the shape of the shroud side 602 of the blade 601 is inclined by θ1 in the rotational direction 604 compared to the shape of the hub side 603, and is directed to the outer edge of the blade. Then, the amount of inclination in the rotational direction is θ2, and further, in R3 (inner edge side approximately two-dimensional shape portion) toward the outer edge of the blade, the shape of the shroud side 602 and the shape of the hub side 603 intersect, It has a substantially two-dimensional shape. In the present invention, θ1 is 11 °, θ2 is 9 °, and θ1> θ2> θ3 (θ3 = 0). That is, the blade 601 is inclined at the maximum in the rotation direction at the inner edge. However, the portion having the maximum inclination may not be the inner edge portion, but may be a portion located slightly on the outer edge side from the inner edge portion. Further, in R4 further from R3 toward the outer edge of the blade, the shape of the shroud side 602 of the blade 601 is inclined by θ4 in the counter-rotating direction compared to the shape of the hub side 603, and R5 ( In the maximum inclination portion in the counter-rotation direction, the amount of inclination in the counter-rotation direction is θ5, and in R6 (outer edge side approximately two-dimensional shape portion) toward the outer edge of the blade, the shape of the shroud side 602 The shape of the hub side 603 intersects again to form a substantially two-dimensional shape. In the present invention, θ4 is −3 °, θ5 is −4 °, and θ4> θ5> θ6 (θ6 = 0). Further, the maximum inclined portion is formed slightly from R5 toward the inner edge side. Further, at R7 (outer edge portion) further from R6 toward the outer edge of the blade, the shape of the shroud side 602 of the blade 601 is inclined by θ7 in the rotational direction as compared with the shape of the hub side 603. In the present invention, θ7 is 0.5 °. That is, in R1 to R2, the shape of the shroud side 602 is inclined in the rotation direction compared to the shape of the hub side 603, becomes a substantially two-dimensional shape in R3, and inclines in the counter-rotation direction as R3 changes to R4 and R5. , R6 again becomes a substantially two-dimensional shape, and the outer edge is again inclined in the rotational direction. That is, when the circles passing on the rotation axis are arranged in order from the inner edge to the outer edge of the blade, the respective circles and the inclination angle θ are in the order of θ1> θ2> θ7> θ3 = θ6> θ4> θ5. The maximum inclination angle of each blade in the shroud formation direction with respect to the hub on the concentric circle is preferably 5 ° to 15 °.

  Of the two substantially two-dimensional shapes, the substantially two-dimensional shape on the inner edge side is located closer to the inner edge side than the intermediate point in the radial direction. On the inner edge side of the substantially two-dimensional shape on the inner edge side, the blade 601 is inclined in the rotational direction, and on the outer edge side of the substantially two-dimensional shape on the inner edge side, the blade 601 is inclined in the counter-rotating direction. The absolute value of the maximum inclination angle (for example, θ1 = 11 °) is larger than the absolute value of the maximum inclination angle in the counter-rotation direction (for example, θ5 = −4 °). Of the two substantially two-dimensional shapes, the substantially two-dimensional shape on the outer edge side is located in the vicinity of the outer edge portion (the inner edge side about several mm from the outer edge portion).

  Next, the blade angle distribution of the blade according to the present invention will be described with reference to FIG. In FIG. 7, an orthogonal line is drawn to a straight line connecting an arbitrary position of the blade and the central axis (the axis of the rotation shaft 308), and an angle formed by the orthogonal line and a tangent line on the outer surface of the blade is a blade attachment angle or The blade angle is “β”. The horizontal axis is the radius. As shown in FIG. 7, the shroud blade angle is set larger than the hub blade angle at the inner edge having the smallest radius. More specifically, when the blade shroud diameter is D and the shroud inner diameter is 0.387D and the hub inner diameter is 0.357D, the shroud blade angle is set to about 25 degrees, and the hub blade angle is about 22 degrees. Set to degrees. That is, at the inner edge, the blade angle on the shroud side is slightly larger than the hub side, and the inner diameter of the shroud is larger than the inner diameter of the hub. At the outer edge having the largest radius, the shroud blade angle is set larger than the hub blade angle, and the shroud side outer diameter of the outer edge of the blade is set larger than the hub side of the outer edge. More specifically, when the shroud diameter at the blade outer edge is D, when the hub side diameter of the trailing edge is 0.996D, the shroud blade mounting angle is about 35 degrees and the hub blade mounting angle is about It is set to 20 degrees.

  Further, the blade angle distribution of the blades in contact with the hub wall increases as it goes from the inner edge to the outer edge of the hub surface as shown by the solid curve in FIG. 7, and reaches the inflection point 702 on the hub side on the inner edge side. The blade angle gradually decreases toward the outer edge and reaches the inflection point 702 on the hub side on the outer edge side. Then, after passing the inflection point 702 on the hub side on the outer edge side, the blade angle decreases again as it goes toward the outer edge. That is, the angular distribution of the blades in contact with the hub is set to have two inflection points 702 on the hub side toward the outer edge. It is possible to have one inflection point depending on the entrance condition.

  Further, as shown by the broken line curve in FIG. 7, the blade angle distribution on the shroud side reaches the inflection point 701 on the shroud side on the inner edge side without increasing the angle immediately after the inner edge as it goes from the inner edge to the outer edge. The blade angle increases toward the outer edge and reaches the inflection point 701 on the shroud side on the outer edge side. Then, after passing the inflection point 701 on the shroud side on the outer edge side, the blade angle of the outer edge is gradually reached toward the outer edge. That is, the angular distribution of the blades in contact with the hub is set so as to have two inflection points 701 on the shroud side toward the outer edge.

  Furthermore, the broken line curve of the blade angle distribution on the shroud side and the solid line curve of the blade angle distribution on the hub side intersect on the outer edge side from the approximate center in the radial direction. On the inner edge side from the intersection 703, the shroud blade angle is smaller than the hub blade angle, and on the outer edge side from the intersection, the shroud blade angle is larger than the hub blade angle. The maximum angle of the blade angle distribution is such that the blade angle of the hub is larger than the blade angle of the shroud. The inflection point of the shroud and the hub is located on the inner edge side with respect to the intersection 703. The intersection 703 may be closer to the inner edge than the substantially central position, or may be closer to the outer edge. The position of the intersection 703 depends on, for example, the flow velocity and the incident angle that flows into the impeller 303.

  Next, FIG. 8 shows a comparison of the efficiency in the design point air volume between the blower according to this embodiment and the comparative example. FIG. 8 compares the numerical analysis results obtained by changing the impeller only in the comparative example and the present embodiment in a state where the diffuser is fixed and the axial power of the blade is constant. As shown in FIG. 8, it can be seen that, according to the blower according to the above-described embodiment, the efficiency of the impeller is slightly increased as compared with the comparative example. In addition, it can be seen that the diffuser efficiency is improved in this embodiment as compared with the comparative example. Furthermore, also in the efficiency of the blower including the impeller and the diffuser, it can be seen that the efficiency of the present example can be improved as compared with the comparative example. According to the air blower which becomes a present Example, compared with a comparative example, a diffuser efficiency improvement is larger than the efficiency improvement of an impeller, and the diffuser efficiency improvement has contributed to the fan efficiency improvement.

  Here, in FIG. 14, the shape figure of the blade | wing of a present Example and the blade | wing of a comparative example is shown. Only a plurality of blades viewed from the front side in the axial direction are shown. FIG. 14A shows the blade of this embodiment, and FIG. 14B shows the blade of this embodiment. In the comparative example, the position of the shroud side coupling portion at the trailing edge of the blade is set in the counter-rotating direction from the position of the hub side coupling portion, and the hub side blade outlet angle and the shroud side blade outlet angle at the trailing edge of the blade are Are the same form. That is, the blade has one substantially two-dimensional shape from the inner edge to the outer edge of the blade. The inclination angle of the inner edge portion of the comparative example in the rotation direction is adjusted to the inclination angle of the inner edge portion of this embodiment in the rotation direction, and the position of one substantially two-dimensional shape of the comparison example (radial position from the axial center). ) Is matched with the position of the substantially two-dimensional shape on the inner edge side of the two substantially two-dimensional shapes of the present embodiment. The air conditioner and the electric blower of the vacuum cleaner are different in size, rotation speed, presence / absence of a diffuser, etc., but the comparative example is, for example, the centrifugal fan of the air conditioner disclosed in Patent Document 2 It is an example applied to the electric blower of the vacuum cleaner.

  In order to investigate the effect that the impeller efficiency of the design point air volume is improved for the electric blower according to this embodiment described above, a comparison of the axial distribution of the wind speed at the impeller exit (from the trailing edge) ( (Numerical analysis results) are shown in FIG. The vertical axis in FIG. 9 indicates the impeller exit speed, and the horizontal axis indicates the axial position from the hub side to the shroud. The average speed at the exit of the impeller is shown at the maximum position on the horizontal axis. In the impeller, the smaller the impeller exit speed, the greater the pressure increase in the impeller and the higher the efficiency. Moreover, in the electric blower of a vacuum cleaner, since a diffuser exists in an impeller exit, distribution of an impeller exit speed is important from the flow matching with a diffuser. From FIG. 9, it can be seen that the average speed is reduced in the present embodiment as compared with the comparative example. Further, comparing the uniformity of the speed in the axial direction, the present embodiment also has a smaller speed difference between the shroud side and the hub side than the comparative example. From the above, the velocity distribution inside the impeller has been improved, and an improvement in efficiency can be seen. In this embodiment, the impeller exit speed increases after decreasing from the hub side to the axial center, and increases after decreasing from the axial center to the shroud. Further, the impeller exit speed is smaller at the axially central portion than at the hub end and the shroud end. Compared with the comparative example, the present example has a lower impeller exit speed in the axially central portion from the hub side.

  Furthermore, FIG. 15 shows a comparison (numerical analysis result) of the internal flow in each cross section in the axial direction of the blade. FIG. 15 shows only two blades 401 out of eight blades 401 that exist on the entire circumference. The lighter the color, the higher the value and the higher the speed. The speed distribution shown in FIG. 15 is not a speed distribution in absolute coordinates based on the electric blower 106 or the diffuser 211 that is a stationary body, but a speed distribution in relative coordinates based on the impeller that is a rotating body. . Therefore, a portion with a low speed (dark portion) in FIG. 15 has a high speed with respect to the diffuser 211, and a portion with a high speed (light portion in FIG. 15) has a high speed with respect to the diffuser 211. The speed is small. FIGS. 15A, 15B, and 15C show the speed distribution of this example, and FIGS. 15D, 15E, and 15F show the speed distribution of the comparative example. 15 (a) and 15 (d) show the velocity distribution in the axial cross section of the hub (connecting portion with the hub wall), and FIGS. 15 (c) and 15 (f) show the axial shroud cross section ( FIG. 15B and FIG. 15E show the axial central cross section (center between the hub wall and the shroud wall).

  Comparing the shroud cross-sections, there is not much difference between the velocity distribution of this example (FIG. 15C) and the velocity distribution of the comparative example (FIG. 15F). This is considered to be because the angular distribution of the shape of the shroud side 501 is both optimized. Even if the central cross-sections are compared, there is no significant difference between the velocity distribution of the present embodiment (FIG. 15B) and the velocity distribution of the comparative example (FIG. 15E). This is also considered to be due to the fact that the angular distribution of the shape at the center in the axial direction is optimized. On the other hand, when the hub cross-sections are compared, the speed distribution (FIG. 15 (a)) of the present embodiment is particularly opposite to the speed distribution of the comparative example (FIG. 15 (d)). The dark part seen in the rotation direction side, that is, the low speed region is small (A part in FIG. 15). As shown in FIG. 7, as a result of reducing the blade angle at the rear edge of the hub, it is considered that the shape of the rear edge of the hub becomes a shape along the flow, and the low speed region can be reduced. As described with reference to FIG. 9, the present embodiment can reduce the speed on the hub side and can also reduce the average speed as a result of the reduction in the low speed region on the hub side as compared with the comparative example.

  Furthermore, in order to investigate the effect that the diffuser efficiency of the design point air volume is improved for the electric blower according to this embodiment described above, a comparison (numerical analysis result) of the internal flow in the axial center cross section of the diffuser is shown in FIG. Show. FIG. 10 shows only two blades 1001 among the 13 diffusers present on the entire circumference. The lighter the color, the higher the value and the higher the speed. That is, if the flow in the diffuser changes uniformly from a light color to a dark color, the pressure is efficiently reduced and the pressure is increased inside the diffuser. From FIG. 10, it can be seen that in the comparative example, the diffuser outlet 1004 has a high speed region 1002 and a low speed region 1003, and the flow from the impeller is not uniformly decelerated. That is, it can be seen that peeling occurs at the diffuser outlet portion 1004 and the loss increases. On the other hand, in the embodiment, it can be seen that there is no high speed region or low speed region in the diffuser outlet portion 1004, and the speed is uniformly reduced. That is, in the example, it can be seen that the pressure increase inside the diffuser is improved as compared with the comparative example, energy loss is reduced, and the efficiency is improved. In addition, the velocity distribution of the hub side cross section and the shroud side cross section of the diffuser of the present example was not significantly different from the velocity distribution of the hub side cross section and the shroud side cross section of the diffuser of the comparative example.

  As described above, this embodiment optimizes the shape of the blade shroud side 501, the shape at the axial center, and the shape of the hub side 502, that is, the shape from the inner edge to the outer edge of each axial cross section. By optimizing, the average speed at the exit of the impeller could be reduced, not only improving the efficiency at the impeller, but also improving the efficiency especially at the diffuser. In particular, as a result of reducing the angle distribution particularly at the rear edge of the hub side 502, the shape of the blade shroud side 501 and the shape of the hub side 502 are not only the inner edge side but also the outer edge when viewed from the rotational axis direction. Crossing even in the vicinity of the part.

  Hereinafter, the manufacturing method of the electric blower of this invention is demonstrated.

  The caulking will be described with reference to FIG. A plurality of caulking projections 1105 (rivets) are respectively installed on the upper end portion (axial front side) on the shroud side and the lower end portion (axial rear side) on the hub side of the blade 1104 corresponding to the blade 306 in FIG. The As described above, the caulking projection 1105 is preferably formed integrally with the blade 1104. A plurality of caulking holes 1102 are provided in the shroud wall 1103 and the hub wall 1101 so as to match the position and number of the caulking projections 1105 of the blades. Accordingly, the relative position between the plurality of caulking holes 1102 of the shroud wall 1103 is a position along the shape of the upper end portion of the blade 1104, and the relative position between the plurality of caulking holes 1102 of the hub wall 1101 is the blade 1104. It is a position along the shape of the lower end of the. The caulking hole 1102 is a through hole. For example, when all are substantially two-dimensional, the relative position between the plurality of caulking holes 1102 of the shroud wall 1103 and the relative position between the plurality of caulking holes 1102 of the hub wall 1101 are substantially the same. Then, on the inner edge side of the blade, the upper end portion of the blade 1104 of the blade 1104 is tilted to the front side in the rotation direction 405 with respect to the lower end portion, so that the relative position between the plurality of caulking holes 1102 of the shroud wall 1103 is Compared to the relative position between the plurality of caulking holes 1102, the position swells forward in the rotational direction 405. In FIG. 11, the shroud and the hub side have three caulking structures. The positions of the caulking protrusions 1105 at the upper end of the blade 1104 correspond to the positions of the caulking protrusions 1105 at the lower end of the blade 1104. By inserting the caulking projection 1105 of the blade 1104 into the caulking hole 1102 of the shroud wall 1103 and the hub wall 1101 and caulking from the outside, the blade 1104 is assembled integrally with the shroud wall 1103 and the hub wall 1101. The blade shape shown in FIG. 11 is a flat blade shape having a blade outer diameter D2 of 89 mm, a blade width b2 of 6.8 mm, and b2 / D2 = about 0.08. Here, caulking means that a caulking projection 1105 is inserted into the caulking hole 1102 and protrudes through the caulking hole 1102 to the opposite side by using a dedicated tool or dedicated equipment. The act of crushing. After the caulking projection 1105 of the blade 1104 is inserted into the caulking hole 1102 of the hub wall 1101 and caulked to fix the vane 1104 to the hub wall 1101, the caulking projection 1105 of the vane 1104 into the caulking hole 1102 of the shroud wall 1103. May be inserted and caulked, or vice versa. Further, the caulking protrusion 1105 of the blade 1104 may be caulked after the caulking hole 1102 of the hub wall 1101 and the caulking hole 1102 of the shroud wall 1103 are inserted.

  Compared with the comparative example, in this embodiment, the blade 1200 is inclined forward in the rotational direction, particularly on the inner edge side of the blade 1200, so that the space between the blade 1200 and the shroud wall 304 and the space between the blade 1200 and the hub wall 305. It becomes difficult to maintain airtightness. Therefore, it is preferable to cover the caulking portion (connection portion) between the blade 1200 and the shroud wall 304 and the caulking portion (connection portion) between the blade 1200 and the hub wall 305 with electrodeposition coating or an adhesive. In particular, those having a lower viscosity than the electrodeposition coating or adhesive used for the comparative examples are preferred. Thereby, it is possible to prevent a gap from being formed in the caulking portion (connecting portion) between the blade 1200 and the shroud wall 304 and the caulking portion (connecting portion) between the blade 1200 and the hub wall 305, and to suppress the disturbance of the air flow, Reduction in efficiency can be suppressed.

  Since the basic configuration is the same as that of the first embodiment, the same elements are denoted by the same reference numerals and the description thereof is omitted.

  In the manufacturing method by caulking described above, when the blades are inclined in the rotational direction, the assembly accuracy is reduced because the blades easily slide in the rotational direction when caulking due to the difference in the rotational direction of the shroud and the hub. There was a problem to do.

  On the other hand, as shown in FIG. 12, in Example 2, the shroud forming direction of each blade relative to the hub is inclined in the rotational direction at the inner edge of the blade, as described above, and the inner edge and the outer edge of the blade are As it goes in between, it inclines in the counter-rotating direction and becomes a substantially two-dimensional shape with the hub side, then further in the counter-rotating direction, again becomes an approximately two-dimensional shape inside the outer edge of the blade, and again at the outer edge of the blade, The blade is inclined in the rotation direction and has a substantially two-dimensional shape with two points from the inner edge to the outer edge of the blade. For this reason, as shown in FIG. 12, by using the caulking projection 1205 on the shroud side 1201 and the hub side 1202 in a substantially two-dimensional shape as shown in FIG. 12, sliding of the blades during caulking can be prevented. The distance b on the hub side 1202 can be manufactured with a predetermined dimension. Further, since the direction in which the blades incline changes on the inner edge side and the outer edge side of the two-point substantially two-dimensional shape, there is also an effect of canceling out the stress during caulking. In order to obtain the effect, a caulking projection may be provided so as to have a substantially two-dimensional shape.

  Compared with the comparative example, in this embodiment, the blade 1200 is inclined forward in the rotational direction, particularly on the inner edge side of the blade 1200, so that the space between the blade 1200 and the shroud wall 304 and the space between the blade 1200 and the hub wall 305. It becomes difficult to maintain airtightness. Therefore, it is preferable to cover the caulking portion (connection portion) between the blade 1200 and the shroud wall 304 and the caulking portion (connection portion) between the blade 1200 and the hub wall 305 with electrodeposition coating or an adhesive. In particular, those having a lower viscosity than the electrodeposition coating or adhesive used for the comparative examples are preferred. Thereby, it is possible to prevent a gap from being formed in the caulking portion (connecting portion) between the blade 1200 and the shroud wall 304 and the caulking portion (connecting portion) between the blade 1200 and the hub wall 305, and to suppress the disturbance of the air flow, Reduction in efficiency can be suppressed.

DESCRIPTION OF SYMBOLS 100 Vacuum cleaner main body 101 Hose coupling 102 Dust collection chamber 103 Paper pack 104 Filter part 105 Motor chamber 106 Electric blower 107 Anti-vibration rubber 108 Blower inlet 109 Blower outlet 110 Code reel 111 Wheel 201 Blower 202 Electric motor 203 Housing 204 End bracket 205, 308 Rotating shaft 206 Rotor 207 Stator 208 Brush 209 Commutator 210, 303, 400, 600 Impeller 211 Diffuser 212 Partition plate 213 Return guide 214, 309 Fan casing 215, 300 Eyepiece portion 216, 302 Sealing material 217 Electric blower inlet 301 Sealing material Fixed parts 304, 402, 1103 Shroud walls 305, 403, 1101 Hub walls 306, 401, 601, 1104, 1200 Blades 307 Root leading edge 310 Radial step 313 Air flow direction 314 Stationary tip 315, 404 Impeller eyeball 316 Axial step 317 Caulking 405, 505, 604, 1203 Rotation direction
501, 602, 1201 Shroud side 502, 603, 1202 Hub side 503 Near entrance 504 Near exit 506, 507 Approximate two-dimensional shape 701 Shroud side inflection point 702 Hub side inflection point 703 Intersection 1001 Blade 1002 High speed range 1003 Low speed Area 1004 Diffuser outlet 1102 Caulking holes 1105 and 1205 Caulking protrusions

Claims (18)

An annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and the shroud, the hub, and the blades are rotated. In the electric blower provided with the electric part,
Each blade is formed of a flat plate,
Each of the blades is twisted from the state twisted in the rotational direction with respect to the rotational axis direction from the inner edge in the radial direction to the outer edge in the radial direction, and then twisted in the anti-rotation direction side, and then twisted again in the rotational direction side. A featured electric blower. An annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and the shroud, the hub, and the blades are rotated. In the electric blower provided with the electric part,
Each blade is formed of a flat plate,
Each of the blades has a rotational axis direction formed from a connecting portion with the hub to a connecting portion with the shroud substantially coincides with the rotating shaft direction at a radially outer edge portion of the blade or is based on the rotating shaft direction. Inclined to the rotation direction side,
Each of the blades has a rotational axis direction formed in the radial intermediate portion of the blade that is inclined to the rotational direction side with respect to the rotational axis direction and to the counter-rotational direction side with respect to the rotational axis direction. The electric blower characterized by having a part. In the electric blower according to claim 2,
The electric blower characterized in that the portion inclined toward the counter-rotation direction is located on the outer edge side in the radial direction than the portion inclined toward the rotation direction. In the electric blower according to claim 2 or 3,
The electric blower characterized in that the maximum inclination angle of the portion inclined to the rotation direction side is 5 degrees to 15 degrees. In the electric blower according to any one of claims 2 to 4,
The electric blower characterized in that a maximum inclination angle of a portion inclined toward the rotation direction side is larger than a maximum inclination angle of a portion inclined toward the counter rotation direction side. An annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and the shroud, the hub, and the blades are rotated. In the electric blower provided with the electric part,
Each blade is formed of a flat plate,
When viewed from the rotational axis direction, there are at least two hub side camber lines at the connecting portion of the blade with the hub and shroud side camber lines at the connecting portion of the blade with the shroud from the radially inner edge to the radially outer edge. Electric blower characterized by crossing at In the electric blower according to any one of claims 1 to 6,
The blade is composed of a material mainly composed of aluminum. The electric blower according to any one of claims 1 to 7, wherein an outer diameter of an impeller composed of the shroud, the hub, and the blades is in a range of φ60 mm to φ120 mm,
The height relative to the hub at the outer edge of the blade is in the range of 6-12 mm;
The thickness of the blade is in the range of 0.5 to 1.5 mm,
The number of blades included in the impeller is in the range of 6 to 9,
The input of the electric blower is in the range of 500W-1500W,
The electric blower characterized in that the maximum rotational speed of the impeller is in the range of 35,000 to 50,000 revolutions per minute. In the electric blower according to any one of claims 1 to 8,
At least one of the connecting portion between the blade and the shroud and the connecting portion between the blade and the hub is covered with an electrodeposition coating or an adhesive. In the electric blower according to any one of claims 1 to 9,
The blade and the shroud are connected by caulking,
The electric blower, wherein the blade and the hub are connected by caulking. In the electric blower according to any one of claims 1 to 10,
The electric blower characterized in that the maximum diameter of the shroud is larger than the maximum diameter of the hub. An annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, and the shroud, the hub, and the blades are rotated. In the electric blower provided with the electric part,
Each blade is formed of a flat plate,
When the angle between the perpendicular line to the straight line connecting the arbitrary position of the blade and the axis of the rotation axis and the tangent line on the outer surface of the blade viewed from the rotation axis direction is defined as the blade angle,
The electric fan according to claim 1, wherein the blade angle on the hub side of the blade is smaller than the blade angle on the shroud side of the blade at the radially inner edge and the radially outer edge. In the electric blower described in claim 12,
The distribution of the blade angle on the shroud side of the blade has two inflection points,
The electric fan according to claim 1, wherein the blade angle distribution on the hub side of the blade has two or one inflection point. In the electric blower according to claim 12 or 13,
The electric fan according to claim 1, wherein the blade angle on the shroud side of the blade is smaller than the blade angle on the hub side of the blade on the radially inner edge side excluding the radially inner edge portion. In an electric vacuum cleaner comprising an electric blower that generates a suction force, a dust collection chamber that communicates with the electric blower, and a suction tool that communicates with the dust collection chamber,
The electric blower includes an annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, the shroud, the hub, and the hub. An electric part that rotates the blade,
Each blade is formed of a flat plate,
Each of the blades is twisted from the state twisted in the rotational direction with respect to the rotational axis direction from the inner edge in the radial direction to the outer edge in the radial direction, and then twisted in the anti-rotation direction side, and then twisted again in the rotational direction side. Characterized vacuum cleaner. In an electric vacuum cleaner comprising an electric blower that generates a suction force, a dust collection chamber that communicates with the electric blower, and a suction tool that communicates with the dust collection chamber,
The electric blower includes an annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, the shroud, the hub, and the hub. An electric part that rotates the blade,
Each blade is formed of a flat plate,
Each of the blades has a rotational axis direction formed from a connecting portion with the hub to a connecting portion with the shroud substantially coincides with the rotating shaft direction at a radially outer edge portion of the blade or is based on the rotating shaft direction. Inclined to the rotation direction side,
Each of the blades has a rotational axis direction formed in the radial intermediate portion of the blade that is inclined to the rotational direction side with respect to the rotational axis direction and to the counter-rotational direction side with respect to the rotational axis direction. And a vacuum cleaner. In an electric vacuum cleaner comprising an electric blower that generates a suction force, a dust collection chamber that communicates with the electric blower, and a suction tool that communicates with the dust collection chamber,
The electric blower includes an annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, the shroud, the hub, and the hub. An electric part that rotates the blade,
Each blade is formed of a flat plate,
When viewed from the rotational axis direction, there are at least two hub side camber lines at the connecting portion of the blade with the hub and shroud side camber lines at the connecting portion of the blade with the shroud from the radially inner edge to the radially outer edge. A vacuum cleaner characterized by crossing at In an electric vacuum cleaner comprising an electric blower that generates a suction force, a dust collection chamber that communicates with the electric blower, and a suction tool that communicates with the dust collection chamber,
The electric blower includes an annular shroud, a hub disposed opposite the shroud, a plurality of blades disposed in a circumferential direction between the shroud and the hub, the shroud, the hub, and the hub. An electric part that rotates the blade,
Each blade is formed of a flat plate,
When the angle between the perpendicular line to the straight line connecting the arbitrary position of the blade and the axis of the rotation axis and the tangent line on the outer surface of the blade viewed from the rotation axis direction is defined as the blade angle,
The blade angle on the hub side of the blade is smaller than the blade angle on the shroud side of the blade at the radially inner edge and the radially outer edge.

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