JP2016130453A - Electric blower and vacuum cleaner equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower capable of preventing occurrence of a problem in welding blades of a closed type centrifugal impeller molded with a thermoplastic resin, and a shroud plate, securing airtightness among the blades, and improving efficiency of the electric blower, and to provide a vacuum cleaner equipped with the electric blower using the blower.SOLUTION: A fan casing including a centrifugal impeller composed of a plurality of blades is disposed between a shroud plate having a suction opening and a hub plate, the shroud plate has an annular portion on the suction opening portion, a curved portion is disposed in a state of being smoothly connected to the annular portion, recessed grooves are formed on positions corresponding to the blades of the centrifugal impeller from the curved portion toward an outer diameter, the blades of the centrifugal impeller are molded integrally with the hub plate, faces opposed to the curved portion of the shroud plate, of the blades are inclined to be closely kept into contact with the curved portion of the shroud plate, and the shroud plate and the blades are integrated by welding.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric blower and a vacuum cleaner equipped with the electric blower.

  As a conventional electric blower for an electric vacuum cleaner, for example, there is one disclosed in JP-A-11-336694 (Patent Document 1).

  An electric blower disclosed in Japanese Patent Application Laid-Open No. 11-336694 includes a resin rear shroud fixed to a rotating shaft of a motor, a resin front shroud facing the resin shroud, and a plurality of shrouds provided between the shrouds. It has a sheet of resin blades, and the meridian surfaces of both shrouds excluding the air inlet portion of the front shroud are configured so as to be symmetrical with each other. The rear shroud and the blade are integrally formed, and the blade and the front shroud are joined by ultrasonic welding.

  Further, as another conventional technique, for example, there is one disclosed in JP 2011-157867 A (Patent Document 2).

  An electric blower disclosed in Japanese Patent Application Laid-Open No. 2011-157867 includes an air guide having an impeller fixed to a rotating shaft of the electric motor, a plurality of guide vanes around the impeller, and the impeller and the air guide. The impeller includes a front shroud, a rear shroud, an inducer, and a plurality of blades. The rear shroud, the inducer, and the blades are integrally formed of resin. The front shroud is made of metal and is provided so as to cover the rear shroud, the inducer, and the upper portions of the plurality of blades, and the blade is provided with a plurality of protrusions. A plurality of square holes into which the protrusions are inserted are provided, and the width of the square holes is set to be larger than the thickness of the blade. A curved surface portion is provided at the joint between the protrusion and the blade.

Japanese Patent Laid-Open No. 11-336694 JP 2011-157867 A

  In the electric blower of Patent Document 1, the rear shroud and the blade are integrally formed of resin, and the blade and the front shroud are joined by ultrasonic welding. The resin material melted from the welded portion is in the flow path of the impeller. There is a possibility that the flow of the protruding air is disturbed and the efficiency of the blower is lowered.

  Moreover, in the electric blower of Patent Document 1, since the positioning at the time of welding the front shroud is not considered, the front shroud is attached eccentrically, and the blower efficiency due to the eccentricity of the intake port may be reduced. Furthermore, since the initial mass unbalance amount increases, the unbalance amount cannot be corrected, and vibration and noise may occur during operation.

  In the technique described in Patent Document 2, the front shroud can be positioned by the square hole of the front shroud and the protrusion of the blade. Further, the front shroud is fixed by thermally welding the protrusions of the blade, so that the molten resin material does not protrude into the impeller flow path.

  However, the front shroud and the blade are fixed only by the welded portion of the protrusion, and leakage between the front shroud and the blade is likely to occur, which may reduce the fan efficiency.

  The object of the present invention is to solve the above-mentioned problems, prevent the occurrence of problems during welding of a closed type centrifugal impeller molded with a thermoplastic resin and a shroud plate, and ensure airtightness between the blades. It is to improve the fan efficiency. Moreover, it is providing the vacuum cleaner which improved the output by improving the electric blower efficiency using this blower.

  In addition, when a brushless motor driven by a low-voltage battery is used, the efficiency of the blower is improved, so that the electric blower input can be lowered to obtain the same output, and a vacuum cleaner with a longer operating time is provided. There is to do.

  In order to solve the above problems, one of the representative electric blowers of the present invention includes an electric motor, a shroud plate having a suction opening, a hub plate fixed to the rotating shaft of the electric motor, the shroud plate and the hub. A fan casing containing a centrifugal impeller composed of a plurality of blades between the plate and the shroud plate having an annular portion in the suction opening and connected to the annular portion A curved surface portion is provided, and a concave groove is formed at a position where the blade is joined to the blade from the curved surface portion to the outer diameter of the shroud plate, the blade is integrally formed with the hub plate, and the concave groove has a plurality of through holes. The blades have projection-like claws at positions corresponding to the through holes, weld ribs are formed at the blade end portions corresponding to the concave grooves, and face the curved surface portion of the shroud plate. The surface is the shroud An electric blower that is inclined so as to be in intimate contact with the curved surface portion of the plate, and the shroud plate, the protruding claw, and the welding rib are melted and joined, and a vacuum cleaner including the electric blower. Achieved.

  One of the electric blowers of the invention includes an electric motor, a shroud plate having a suction opening, a hub plate fixed to the rotating shaft of the electric motor, and a plurality of blades between the shroud plate and the hub plate. A fan casing containing the constructed centrifugal impeller, wherein the electric motor operates at a maximum rotational speed of 80,000 to 100,000 revolutions per minute, and the electric blower input is in a range of approximately 200 W to 500 W, The outer diameter of the centrifugal impeller is in the range of φ35 mm to φ55 mm, the blade outlet height of the centrifugal impeller is in the range of about 3 mm to 6 mm, and the blade thickness of the centrifugal impeller is about 0.5 mm to 1.5 mm, the number of blades of the centrifugal impeller is in the range of approximately 6 to 9, and the shroud plate has an annular portion at the suction opening, and is connected to the annular portion. Song to do A surface portion is provided, and a concave groove is formed at a position joining the blade from the curved surface portion to the outer diameter of the shroud plate, the blade is integrally formed with the hub plate, and the concave groove has a plurality of through holes. The blade has a projection-like claw at a position corresponding to the through hole, a welding rib is formed at the blade end corresponding to the concave groove, and the surface facing the curved surface portion of the shroud plate Is an electric blower that is a closed type centrifugal impeller that is inclined so as to be in close contact with the curved surface portion of the shroud plate, and the shroud plate, the protruding claws, and the welding rib are melted and joined, This is achieved by providing a vacuum cleaner equipped with an electric blower.

  ADVANTAGE OF THE INVENTION According to this invention, the electric blower which can improve fan efficiency reliably compared with a conventional one, and a vacuum cleaner provided with the same can be provided.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is the perspective view represented with the cross section of one Example of the centrifugal impeller by this invention. It is a block diagram of one Example of the centrifugal impeller by this invention. It is an external view of the shroud board which comprises the centrifugal impeller in one Example of this invention. It is a cylinder development view of the pressure side of one blade which constitutes a centrifugal impeller in one example of the present invention. It is a longitudinal cross-sectional view of the electric blower in one Example of this invention. It is an external appearance perspective view of the vacuum cleaner to which the electric blower in one Example of this invention is applied. It is sectional drawing which showed typically the vacuum cleaner main body in the vacuum cleaner of FIG.

  An embodiment of the present invention will be described below with reference to the drawings.

  A vacuum cleaner according to an embodiment of the present invention will be described with reference to FIGS. FIG. 6 shows an external perspective view of a vacuum cleaner to which the electric blower of the present embodiment is applied.

  As shown in FIG. 6, 100 is a vacuum cleaner body that houses a dust collection chamber for collecting dust and an electric blower 200 (FIG. 6) that generates a suction airflow necessary for collecting dust, and 101 is a vacuum cleaner body at one end. Hose connected to 100, 102 is a hand operating part with one end connected to the other end of the hose 101, 103 is an extension pipe with one end connected to the other end of the hand operating part 102, and 104 and 105 are extension pipes 103. It is the 1st and 2nd suction mouth connected to the other end. Reference numeral 106 denotes a switch unit for turning on and off the electric blower 200 provided in the hand operation unit 102.

  In the above configuration, when the switch unit 106 of the hand operation unit 102 is operated, the electric blower 200 housed in the cleaner body 100 is operated to generate a suction airflow. Then, dust is sucked from the suction body 105 and collected in the dust collection chamber of the cleaner body 100 through the extension pipe 103, the hand operation unit 102, and the hose 101.

  Next, the cleaner body 100 will be described using a cross-sectional view schematically showing the cleaner body 100 in the electric vacuum cleaner shown in FIG.

  An electric blower 200 that generates suction force, a battery unit 107 that drives the electric blower 200, a drive circuit 108, and a dust collection chamber 109 are disposed inside the vacuum cleaner main body 100, and are sucked by the suction force of the electric blower 200. A paper pack 110 (collecting member) that collects dust, and a filter 111 through which air from which dust has been removed by the paper pack 110 pass are disposed. The electric blower 200 is accommodated in the electric blower chamber 112 of the vacuum cleaner main body 100 via the anti-vibration rubber 113. In the present embodiment, a paper pack dust collector term in which the paper pack 110 is attached to the dust collection chamber 109 is used, but a cyclone dust collection mechanism may be used.

  Next, the electric blower 200 will be described with reference to a longitudinal sectional view of the electric blower shown in FIG. The electric blower 200 is roughly divided into a blower unit 201 and an electric motor unit 202. The blower unit 201 includes a centrifugal impeller 203, a fan casing 204 that houses the centrifugal impeller 203, a diffuser 205, and a stationary flow path unit having a return guide 206 on the back surface of the diffuser 205. The fan casing 204 is provided with an air suction port 204a, is provided with a seal portion 204b, and a seal member 207 is provided. The centrifugal impeller 203 has a suction opening 203a, and the suction opening 203a and the seal member 207 are substantially in contact with each other to prevent leakage. The centrifugal impeller 203 is made of a thermoplastic resin and is directly connected to the rotating shaft 208.

  A metal support sleeve 209 formed by sintering or the like is attached to the central portion of the centrifugal impeller 203. The support sleeve 209 has an inner peripheral surface into which the rotary shaft 208 is press-fitted. Such a support sleeve 209 is insert-molded in the centrifugal impeller 203. The centrifugal impeller 203 is fixed by press-fitting the rotation shaft 208 into the support sleeve 209. In this embodiment, the centrifugal impeller 203 is press-fitted and fixed to the rotary shaft 208, but a screw may be provided at the end of the rotary shaft 208 and the centrifugal impeller 203 may be fixed using a fixing nut.

  The electric motor unit 202 includes a rotor 211 fixed to a rotary shaft 208 housed in the housing 210 and a stator 212 fixed to the housing 210. A conductor (not shown) is wound around the stator 212 and forms a phase winding together. The phase winding is electrically connected to a circuit unit (not shown) provided in the electric blower 200.

  The rotor 211 is formed on the end side of the anti-centrifugal impeller 203 of the rotating shaft 208 and is made of a rare earth bond magnet. A rare earth bond magnet is made by mixing a rare earth magnetic powder and an organic binder. As the rare-earth bond magnet, for example, a samarium iron nitrogen magnet or the like can be used. In this embodiment, a permanent magnet is used for the rotor 211, but it is not trapped by this, and for example, reluctance is a kind of a non-commutator motor that can rotate at a high speed of 80,000 or more per minute. A motor or the like may be used.

  The housing 210 has a support portion 210 a that fixes a cylindrical bearing cover 214 that contains the bearing 213. A bearing 213, a sleeve 215, and a spring 216 are provided in the bearing cover 214. The springs 216 are arranged in a compressed state, and abut against the outer rings of the bearings 213 to apply preload.

  A screw hole 210b extending in the axial direction is formed at the end of the support portion 210a. A fixing screw 217 can be screwed into the screw hole 210b. A diffuser 205 is fixedly installed at the end of the support portion 210 a by screwing a fixing screw 217.

  The housing 210 is provided with a plurality of openings 210c so that air flows into the housing and a plurality of exhaust ports 210d for discharging the air to the outside of the electric blower 200.

  Next, the flow of air in the electric blower 200 will be described. When the electric motor 202 is driven to rotate the centrifugal impeller 203, air flows from the air suction port 204 a of the fan casing 204 and flows into the centrifugal impeller 203. The air that has flowed in is boosted and accelerated in the centrifugal impeller 203 and is discharged from the centrifugal impeller 203. The air flow discharged from the centrifugal impeller 203 is guided to the diffuser 205.

  The diffuser 205 is provided with a plurality of diffuser blades, and when the air flow is decelerated between the blades of the diffuser blades, the kinetic energy of the air flow is converted into pressure energy and the pressure rises. The air flow discharged from the diffuser 205 flows into the return guide 206 from a flow path formed between the inner surface of the fan casing 204 and the rear edge of the diffuser 205. In addition, although the diffuser with a blade | wing is used in a present Example, it is good also as a diffuser without a blade | wing. In that case, a plurality of support columns are provided on the rear edge side of the diffuser to support the fan casing 204.

  The air flow that has passed through the return guide 206 is guided to the space S1 between the housing 210 and the fan casing 204, flows into the housing 210 through the opening 210c of the housing 210, the bearing cover 214 is cooled, and the air is passed through the bearing cover 214. The bearing 213 is cooled. Further, the conductor 211 (not shown) wound around the rotor 211, the stator 212, and the stator 212 is cooled and discharged to the outside. A part of the air flow guided to the space S1 is discharged to the outside from the exhaust port 210d of the housing 210. Thereby, each part in the housing 210 is cooled.

  An embodiment of the present invention will be described with reference to FIGS. 1A is a perspective view showing a cross section of an embodiment of a centrifugal impeller according to the present invention, FIG. 1B is a meridional shape diagram, FIG. 2 is a configuration diagram of an embodiment of the centrifugal impeller, FIG. Is an external view of a shroud plate constituting a centrifugal impeller, (a) is a rear perspective view, (b) is a side view, (c) is a rear view, and FIG. FIG. 2B is a cross-sectional view of the blades in a developed cylindrical view on the pressure surface side of the sheet.

  As shown in FIGS. 1 to 4, a centrifugal impeller 203 according to an embodiment of the present invention includes a shroud plate 1, a hub plate 2, and a plurality of blades 3. The hub plate 2 and the blade 3 are integrally formed of a thermoplastic resin.

  The shroud plate 1 made of a thermoplastic resin is formed with an annular suction opening 4 for sucking air at the center. The suction opening 4 is provided with a straight portion 5 substantially parallel to the rotation shaft 208 and has a thin plate at the tip. The shroud plate 1 is provided with a curved surface portion 6 for turning the axial flow flowing from the suction opening 4 into a radial flow, the straight portion 5 and the curved surface portion 6 are smoothly connected, and the radial direction from the curved surface portion 6 to the outer diameter is provided. It is formed to face.

  On the flow path surface of the shroud plate 1, a concave groove 7 is formed at a position corresponding to the blade 3 from the curved surface portion 6 to the outer diameter, and the concave groove 7 is provided with through holes 8a and 8b. A concave groove 7 is formed from the through hole 8a on the inner diameter side and extends to the outer diameter side.

  At the center of the hub plate 2, a convex boss 9 to which the rotary shaft 208 is inserted and fixed is formed. The blades 3 formed integrally with the hub plate 2 are installed at equal intervals in the circumferential direction, and have a blade shape that retreats in the rotation direction from the inner diameter side toward the outer diameter direction. Protruding claws 10 a and 10 b are formed on the upper surface of the blade 3. A welding rib 11 is formed between the claw 10a and the claw 10b and on the upper surface of the blade 3 on the outer diameter side from the claw 10b. An inclined surface 12 is formed on the pressure surface (convex surface) side of the blade 3 so that the upper surface of the blade 3 on the inner diameter side from the claw 10 a of the blade 3 is in close contact with the curved surface portion 6 of the shroud plate 1. Although the shape of the welding rib 11 shown in FIG. 4 is a triangle, it may be a semicircle or a trapezoid.

  The heights of the claws 10a and 10b are set so as to protrude from the shroud plate 1 by about 0.2 mm to 0.5 mm. The volume of the welding rib 11 is smaller than the volume of the gap when the blade 3 is inserted into the concave groove 7.

  The protrusion-like claw 10a of the blade 3 and the through-hole 8a of the shroud plate 1, the claw 10b and the through-hole 8b, and the concave groove 7 of the shroud plate 1 and the blade 3 are engaged, and the claw 10a, the claw 10b, and the welding rib 11 are engaged. The centrifugal impeller 203 is formed by joining the two by welding. In addition, the welding process is not given to the curved surface part 6 of the shroud board 1 and the inclined surface 12 of the blade | wing 3 which are shown by X of FIG.1 (b).

  The welding process of the through-hole 8a and the protruding claw 10a, and the through-hole 8b and the claw 10b can be performed from substantially the axial direction. When performing the welding process by providing the through hole 8a and the protruding claw 10a at the position X in FIG. 1B, it is necessary to perform the welding process from the substantially radial direction in addition to the welding process in the substantially axial direction. The welding process of the through hole 8a and the protruding claw 10a and the through hole 8b and the claw 10b cannot be performed simultaneously. However, in the present embodiment, since the curved surface portion 6 of the shroud plate 1 and the inclined surface 12 of the blade 3 are not welded, the curved surface portion 6 of the shroud plate 1 extends from the substantially axial direction to the outer diameter. Two welding processes can be performed at a time only by the welding process.

  Although the welding rib 11 melts in the concave groove 7, the volume of the welding rib 11 is made smaller than the volume of the gap when the blade 3 is inserted into the concave groove 7, so that the melted resin material flows in the centrifugal fan flow It does not protrude into the road. Further, since the height of the claw 10 of the blade 3 is higher than the thickness of the shroud plate 3, the claw 10 is melted so that the through holes 8a and 8b of the shroud plate 1 are closed, and the through hole 8a. No air leaks from 8b.

  Moreover, since the welding rib 11 of the blade 3 is melted and welded to the shroud plate 1 in the flow channel where the pressure from the vicinity of the channel to the outlet becomes high, leakage between the blades 3 can be prevented. it can.

  Further, an inclined surface 12 is formed on the front edge side of the blade 3 from the claw 10 a so as to coincide with the shape of the curved surface portion 6 of the shroud plate 1. In the centrifugal impeller 203, the inlet flow is particularly important, and the curved surface portion 6 of the shroud plate 1 is not welded, so that no burr or the like due to welding occurs on the inclined surface 12 portion of the blade 3. That is, the air can be smoothly introduced into the blade 3 without disturbing the flow on the inlet side.

  Further, since the suction opening 4 of the shroud plate 1 is formed, the straight part 5 is provided, and the curved surface part 6 is smoothly formed, the axial flow flowing from the suction opening 4 is smoothly turned to the radial flow. It can be made to flow into the blade 3, and the bending loss at the inlet can be reduced.

  Further, the shroud plate 1 is accurately positioned by the claws 10 of the blades 3 and the through holes 8a and 8b of the shroud plate 3. Therefore, the suction opening 4 can increase the concentricity with the rotating shaft 208. For this reason, by suppressing the surface shake of the centrifugal impeller 203, the flow from the centrifugal impeller 203 to the diffuser 205 can be made uniform, and the performance of the diffuser 205 can be improved.

  Further, since the suction opening 4 is formed with a thin plate at the tip, in addition, since the surface vibration of the centrifugal impeller 203 is suppressed, the friction loss at the seal portion 204b provided in the fan casing 204 is reduced. In addition, the amount of air leakage at the inlet can be reduced.

  In the present embodiment, the protruding claws 10 and the through holes 8a and 8b are provided in two locations on one blade 3, but may be three locations or one location on the inner diameter side. Further, although the through holes 8a and 8b are used, it is only necessary that the holes can be fitted with the protruding claws 10 of the blade 3 without penetrating and the position of the shroud plate can be determined.

  As shown in Patent Document 2, the shroud plate 1 of an electric blower mounted on a household vacuum cleaner is generally made of metal, and the tip of the suction opening 4 is generally thinned by cutting. In this embodiment, since the shroud plate 1 is made of resin, the tip portion can be made thin with high accuracy. Therefore, it is not necessary to perform secondary machining, and manufacturing costs can be reduced.

  Further, the initial mass unbalance amount can be reduced, the unbalance amount can be easily corrected, and the occurrence of vibration and noise during operation can be prevented.

  Although the centrifugal impeller 203 is made of a thermoplastic resin, an engineering plastic material having a heat resistance of 100 ° C. or higher and a tensile strength of 100 MPa or higher is preferred in order to withstand centrifugal stress in order to prevent deformation caused by heat generated by an electric motor or the like. . For example, it is more desirable that the polyether ether ketone (PEEK) or PEEK contains carbon fibers.

  According to the electric blower 200 of the present embodiment described above, the resin material melted by welding does not protrude into the flow path of the centrifugal impeller 203, and the airtightness in the flow path can be reliably obtained. Thereby, the efficiency of the electric blower 200 can be improved reliably.

  Further, the inclined surface 12 is formed on the front edge side of the centrifugal impeller 203 so as to coincide with the shape of the curved surface portion 6 of the shroud plate 1. During operation, the blade 3 and the shroud plate on the inlet side have a large influence on the performance of the centrifugal impeller 203 because the curved portion 6 of the shroud plate 1 and the inclined portion 12 of the blade 3 are in close contact with each other due to centrifugal force. Thus, the efficiency of the electric blower 200 can be reliably improved.

  In addition, since no welded portion is provided on the inlet side, burrs due to welding do not occur. Therefore, the flow is not disturbed on the inlet side, air can be smoothly flowed into the blades 3, and the efficiency of the electric blower 200 can be reliably improved.

  Moreover, since the straight part 5 is provided in the suction opening 4 formed in the shroud plate 1 and is smoothly formed with the curved surface part 6, the axial flow flowing in from the suction opening 4 is smoothly turned into the radial flow, The air can flow into the blade 3. Therefore, the bending loss at the inlet of the centrifugal impeller 203 can be reduced, and the efficiency of the electric blower 200 can be improved.

  Furthermore, the concentricity of the shroud plate 1 with the rotating shaft 208 can be increased, and the friction loss at the seal portion 204b provided in the fan casing 204 can be reduced, and the amount of air leakage at the inlet portion can be reduced. . In addition, the initial mass unbalance amount can be reduced, the unbalance amount can be easily corrected, and the generation of vibration and noise during operation can be reduced.

  Since the centrifugal impeller 203 is made of an engineering plastic material, a resin centrifugal impeller that can suppress deformation caused by heat and centrifugal force generated during operation, ensures strength, and can withstand high-speed rotation. 203 can be realized.

  By mounting the electric blower 200 on a vacuum cleaner, the output of the vacuum cleaner can be improved. Further, by improving the efficiency of the electric blower 200, the input of the electric blower 200 can be lowered when the same output is obtained, and the operation time can be extended in the rechargeable cleaner using a battery as a drive source. .

  Next, an embodiment of the present invention will be described. Since the basic configuration is the same as that of the above embodiment, the same configuration will be described using the same reference numerals.

  The maximum rotational speed of the electric blower for a vacuum cleaner targeted by the present invention operates at 80,000 to 100,000 revolutions per minute, and the outer diameter of the centrifugal impeller 203 is in the range of approximately 35 mm to 55 mm. The outlet height is in the range of about 3mm to 6mm, the blade thickness is in the range of about 0.5mm to 1.5mm, the number of blades is in the range of about 6 to 9, and the electric blower input is about It is intended for stick-type and handy-type rechargeable vacuum cleaners in the range of 200W to 500W.

  As shown in FIGS. 1 to 4, a centrifugal impeller 203 according to an embodiment of the present invention includes a shroud plate 1, a hub plate 2, and a plurality of blades 3. The hub plate 2 and the blade 3 are integrally formed of a thermoplastic resin.

  The shroud plate 1 made of a thermoplastic resin is formed with an annular suction opening 4 for sucking air at the center. The suction opening 4 is provided with the straight portion 5 in parallel with the rotation shaft 208, and the thickness of the tip is thin. The shroud plate 1 is provided with a curved surface portion 6 for turning an axial flow flowing from the suction opening 4 into a radial flow, the straight portion 5 and the curved surface portion 6 are smoothly connected, and the radius extends from the curved surface portion 6 to the outermost diameter. It is formed to face the direction.

  On the flow path surface of the shroud plate 1, a concave groove 7 is formed at a position corresponding to the blade 3 from the curved surface portion 6 to the outer diameter, and the concave groove 7 is provided with through holes 8a and 8b. A concave groove 7 is formed from the through hole 8a on the inner diameter side and extends to the outer diameter side.

  A convex boss 9 is formed in the center of the hub plate 2 to which the rotary shaft 208 is inserted and fixed. The blades 3 formed integrally with the hub plate 2 are installed at equal intervals in the circumferential direction, and have a blade shape that retreats in the rotation direction from the inner diameter side toward the outer diameter direction. Protruding claws 10 a and 10 b are formed on the upper surface of the blade 3. A welding rib 11 is formed between the claw 10a and the claw 10b and on the upper surface of the blade 3 on the outer diameter side from the claw 10b. An inclined surface 12 is formed on the pressure surface (convex surface) side of the blade 3 so that the upper surface of the blade 3 on the inner diameter side from the claw 10 a of the blade 3 is in close contact with the curved surface portion 6 of the shroud plate 1. Although the shape of the welding rib 11 shown in FIG. 4 is a triangle, it may be a semicircle or a trapezoid.

  The heights of the claws 10a and 10b are set so as to protrude from the shroud plate 1 by about 0.2 mm to 0.5 mm. The volume of the welding rib 11 is smaller than the volume of the gap when the blade 3 is inserted into the concave groove 7.

  The protrusion-like claw 10a of the blade 3 and the through-hole 8a of the shroud plate 1, the claw 10b and the through-hole 8b, and the concave groove 7 of the shroud plate 1 and the blade 3 are engaged, and the claw 10a, the claw 10b, and the welding rib 11 are engaged. The centrifugal impeller 203 is formed by joining the two by welding. The curved surface portion 6 of the shroud plate 1 is not welded.

  In a stick-type or handy-type rechargeable vacuum cleaner, the electric blower input is determined from the battery capacity, operation time, weight, and the like. The average cleaning time at home is about 10 minutes. For example, if six batteries having a rated battery voltage of 21.6 V and a rated current capacity of 2500 mAh are used, the total battery power capacity is 54 Wh. Considering an operating time of 10 minutes, the electric blower input is approximately 320W.

  The rechargeable vacuum cleaner has a lower input than a vacuum cleaner using a general household power source and is inferior in suction power, but it is easy to use because it does not require replacement of the electric cord in the room. In order to increase the suction force of the rechargeable vacuum cleaner, the efficiency of the electric blower 200 needs to be increased. In addition, it is advantageous to reduce the size and weight in terms of usability.

  In order to reduce the size and weight of the rechargeable vacuum cleaner, it is necessary to reduce the size and weight of the electric blower 200. In order to reduce the size and weight of the electric blower 200, it is effective to rotate the electric blower 200 at a high speed. In order to increase the speed, the motor 202 is advantageously a non-commutator motor that does not use a brush.

  In a rectifier motor mounted on a general vacuum cleaner, the maximum rotation speed is about 50,000 rotations per minute, the centrifugal impeller outer diameter is about φ60 mm to φ120 mm, and the centrifugal impeller is a metal shroud. A plate, a hub plate, and a blade are provided, and each is fixed to the shroud plate and the hub plate by crimping a protruding claw provided on the blade.

  In general, the speed of the blower can be increased by increasing the speed, which is advantageous for increasing the efficiency. In addition, the speed and speed can be reduced in size and weight. On the other hand, since the motor increases in mechanical loss such as bearings by increasing the speed, the motor efficiency decreases by increasing the speed. That is, the efficiency of the electric blower 200 has a rotational speed range having a peak with respect to the rotational speed. From the blower efficiency and the motor efficiency, it is advantageous to operate at a rotational speed of 80,000 to 100,000 revolutions per minute.

  In order to reduce the size and weight of rechargeable vacuum cleaners, it is better to use fewer batteries. However, if the number of batteries is small, the input becomes small and the suction force decreases. The electric blower input is preferably in the range of 200W to 500W from the capacity and mass of the battery.

  If the rotational speed of the electric blower 200 is 80,000 to 100,000 revolutions per minute, and the input of the electric blower 200 is in the range of approximately 200 W to 500 W, the outer diameter of the centrifugal impeller 203 is approximately φ35 mm to φ55 mm, the blade outlet height By setting the length to about 3 mm to 6 mm and the number of blades to about 6 to 9, a highly efficient closed type centrifugal impeller 203 can be obtained.

  By mounting the electric blower 200 on a vacuum cleaner, the output of the vacuum cleaner can be improved. Further, by improving the efficiency of the electric blower 200, it is possible to lower the input of the electric blower 200 to obtain the same output, and it is possible to lengthen the operation time in a rechargeable cleaner using a battery as a drive source. About an effect, it is the same as that of Example 1.

DESCRIPTION OF SYMBOLS 1 Shroud board 2 Hub board 3 Blade | blade 4 Suction opening 5 Straight line part 6 Curved surface part 7 Concave groove 8 Through hole 9 Boss 10 Projection-shaped claw 11 Rib 12 Inclined surface 100 Vacuum cleaner 200 Electric blower 201 Blower part 202 Electric motor part 203 Centrifugal Blower 204 Fan casing 205 Diffuser 206 Return guide 207 Seal member 208 Rotating shaft 209 Support sleeve 210 Housing 211 Rotor 212 Stator 213 Bearing 214 Bearing cover 215 Sleeve 216 Spring 217 Fixing screw

Claims (7)

An electric motor, a shroud plate having a suction opening, a hub plate fixed to the rotating shaft of the electric motor, and a fan casing containing a centrifugal impeller composed of a plurality of blades between the shroud plate and the hub plate With
The shroud plate has an annular portion in the suction opening, a curved portion is provided so as to connect to the annular portion, and a concave shape is formed at a position where the shroud plate joins the blade from the curved portion to the outer diameter. Grooves are formed,
The blade is integrally formed with the hub plate, and a surface of the blade facing the curved portion of the shroud plate is inclined so as to be in close contact with the curved portion of the shroud plate, and the shroud plate and the blade are joined by welding. An electric blower characterized by An electric motor, a shroud plate having a suction opening, a hub plate fixed to the rotating shaft of the electric motor, and a fan casing containing a centrifugal impeller composed of a plurality of blades between the shroud plate and the hub plate With
The motor operates at a maximum speed of 80,000 to 100,000 revolutions per minute,
The electric blower input is in the range of approximately 200W to 500W,
The outer diameter of the centrifugal impeller is in the range of φ35 mm to φ55 mm,
The blade outlet height of the centrifugal impeller is in the range of about 3 mm to 6 mm,
The thickness of the centrifugal impeller blades is approximately in the range of 0.5 mm to 1.5 mm.
The number of blades of the centrifugal impeller is in the range of approximately 6 to 9 blades,
The shroud plate has an annular portion in the suction opening, a curved portion is provided to connect to the annular portion, and the shroud plate is located at a position where the shroud plate is joined to the blade from the curved portion to the outer diameter. A concave groove is formed,
The blade is integrally formed with the hub plate, and a surface of the blade facing the curved surface portion of the shroud plate is inclined so as to be in close contact with the curved surface portion of the shroud plate,
The centrifugal impeller includes a closed type centrifugal impeller in which the shroud plate and the blade are joined by welding. In claim 1 or claim 2,
The concave groove is provided with a plurality of holes, the blade has a protruding claw at a position corresponding to the hole, a welding rib is formed at the blade end corresponding to the concave groove, and the shroud plate The electric blower characterized in that the protruding claws and the welding rib are melted and joined.   The electric blower according to claim 3, wherein the concave groove is formed on the outer diameter side from the innermost diameter of the hole. In the electric blower described in claim 1 or claim 2,
The electric blower is characterized in that the centrifugal impeller is made of an engineering plastic material having a heat resistance of 100 ° C. or more and a tensile strength of 100 MPa or more.   6. The diffuser that performs a rectifying action while restoring pressure to the outer periphery of the centrifugal impeller, and a seal portion is provided at a suction port of the fan casing, according to claim 1. Electric blower.   The vacuum cleaner provided with the electric blower described in any one of claims 1 to 6.