TW201839272A - Electric blower and electric vacuum cleaner having the same having advantages of small volume and low noise and low frequency noise generated through wind passing vanes and good sound quality - Google Patents

Abstract

To provide an electric blower having a high efficiency in a large wind area and having advantages of small volume and low noise and low frequency noise generated through wind passing vanes and good sound quality and capable of being provided under a situation of prohibiting uneven performances during a massive production, and also to provide an electric vacuum cleaner having an increased sucking force in a large wind area and having advantages of small size and quiet operation and good sound quality. The electric blower includes: a motor, having a rotor and a stator; a casing, having one end thereof formed as an opening side for receiving the motor; a rotation shaft, arranged on the rotor; a rotation wing, fixedly arranged on the rotation shaft; a partition plate, arranged at one side of the motor where the rotation wing is disposed; a plurality of diffusion wings, arranged at an outer periphery of the rotation wing at the opening side of the casing; and a fan case member, covering the diffusion wings, wherein the diffusion wings are formed with a throat part via the adjacent wings, the throat part is formed at a location defined at a further rear edge relative to the center of the wing chord length of the adjacent wings, and the quantity of the diffusion wings is 15 to 17.

Description

Electric blower and electric vacuum cleaner with electric blower

[0001] The present invention relates to an electric blower and an electric vacuum cleaner equipped with the electric blower.

[0002] A blower of the prior art is disclosed in Japanese Patent No. 5903756 (Patent Document 1). [0003] In Patent Document 1, a centrifugal compressor used in a vacuum cleaner is provided with a fan blade and a diffuser, and operates between a low flow rate and a high flow rate, and the fluid is in the foregoing. In the low flow rate, the fan blade flows out at a first flow angle, and at the high flow rate, the fan blade flows out at a second flow angle, and the first flow angle and the second flow The difference between the angles is at least 20 degrees, and the diffuser is provided with a plurality of radial vanes. In order to recover the positive pressure between the low flow rate and the high flow rate without causing the stall to occur, the radius is The number of blades of the direction leaves is 15 to 20, and the trueness of the radial direction leaves is 0.6 to 0.8. The radius ratio of the radial direction leaves from the leaf inlet to the fan blade exit is not At 1.5, the fan blade is rotated at a speed exceeding 80 krpm in both the low flow rate and the high flow rate. [Prior Art Document] [Patent Document] [0004] [Patent Document 1] Japanese Patent No. 5903756

[Problems to be Solved by the Invention] [0005] The electric vacuum cleaner is caused by the clogging of the filter screen and the material of the floor of the cleaning target, and the operating air volume is greatly changed. There is a demand for strong electric blowers in a wide range of air volume. Further, the wing passing frequency noise obtained by multiplying the number of blades of the impeller and the number of rotations is related to the sound quality during operation, and it is required to be able to reduce it. [0006] A fan-attached diffuser can perform excellent pressure recovery at a design point air volume, but at a non-design point air volume, the inlet angle of the diffuser blade and the air flow toward the diffuser The inconsistency of the inflow angle will reduce the performance of the diffuser. Therefore, there is a problem that the attractiveness of the electric vacuum cleaner is high at the design point air volume but is lowered at the non-design point air volume. [0007] For a vacuum cleaner that is driven by a battery (secondary battery), such as a wireless upright type or an autonomous walking type, the power consumption of the electric blower is small, and the maximum air volume is also small. Therefore, there is a problem that the dust transporting ability is lowered and the suction force of the vacuum cleaner is lowered when the filter is clogged. Further, a wireless upright type or a vacuum cleaner that is driven by a battery (secondary battery) is required for small size and light weight, and it is required to simultaneously achieve "a wide air volume" for an electric blower to be mounted on a vacuum cleaner. Within the scope, the attraction is strong, the "small", and the "wing wing during operation are small in frequency noise". [0008] Patent Document 1 describes a "diffuser" having a plurality of radial vanes, and in order to recover a positive pressure between the low flow rate and the high flow rate without causing a stall, the aforementioned The number of blades in the radial direction is 15 to 20, and the radius of the radial direction is 0.6 to 0.8. The radius ratio of the radial direction leaves from the leaf inlet to the fan blade exit is In the case of less than 1.5", Patent Document 1 describes a centrifugal compressor equipped with a diffuser. The diffuser mounted on the centrifugal compressor is capable of recovering a positive pressure within the operating range without causing stall. In addition, it is described that "the degree of solidity is preferably in the range of 0.6 to 0.65". Here, the actual value is a value obtained by dividing the "wing chord length" by "the circumferential distance (mounting interval) between adjacent wings at the entrance radius of the diffusion wing". [0009] The centrifugal compressor described above has a small operating range of 0.8 or less. Therefore, it is possible to obtain a wide operating range. However, it is conceivable that there is still room for improvement in the efficiency of the blower. In addition, when the solidity is small, since the chord length is small, in order to perform resin molding, if the maximum thickness of the blade is not set to be large, the resin is difficult to flow during molding, and It is easy to produce a short shot or a whisker, and there is a possibility that the performance is a cause. Further, if the maximum thickness of the wing is increased, the resistance of the wing is increased, and there is a problem that the efficiency of the blower is lowered. [0010] An object of the present invention is to solve the above problems, and to improve the efficiency, and to achieve mass productivity, deterioration in operation sound, and improvement in sound quality due to reduction in wing pass frequency noise. In other words, it is an electric blower that is high-efficiency in the wide air volume region and is small and lightweight, and the noise is small and the sound quality of the wing is small, and the sound quality is good, and the performance variation in the mass production is suppressed. The state is provided, and an electric vacuum cleaner which is small in size and has a small sound quality and excellent sound quality is provided in the wide air volume region. [Means for Solving the Problem] In order to solve the above problems and achieve the above object, for example, the configuration described in the scope of the patent application is adopted. [0012] The present invention includes a plurality of means for solving the above-mentioned problems. However, an example of the present invention is achieved by the following configuration: that is, a motor including a rotor and a rotor a stator; and a housing, wherein one end is open and accommodates the motor; and a rotating shaft is disposed at the rotor; and a rotating wing is fixed to the rotating shaft; and the partition plate is disposed at a motor side of the rotary wing; and a plurality of diffusion wings disposed at an outer peripheral portion of the rotary wing at an opening side of the casing; and a fan casing covering the diffusion wing, the diffusion wing, The throat portion is formed by abutting the wing, and the throat portion is formed at a center of the chord length of the adjacent wing and further at the trailing edge side, and the number of the diffusion wings is 15 to 17. [Effect of the Invention] According to the present invention, in addition to being able to increase the efficiency, it is possible to achieve mass productivity, a reduction in operational sound, and a reduction in sound quality due to a decrease in wing pass frequency noise. In other words, it is an electric blower that is high-efficiency in the wide air volume area and is small and lightweight at the same time, and the wing pass frequency noise is also small and the sound quality is good, and the performance variation in the mass production is suppressed. The state is provided, and it is possible to provide an electric vacuum cleaner which is small in size and has a good sound quality and is excellent in sound quality in a wide air volume region. [0014] The problems, configurations, and effects other than the above description will become more apparent from the description of the embodiments below.

[0016] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. [Embodiment 1] [0017] An electric vacuum cleaner 400 according to one embodiment of the present invention will be described with reference to Figs. 7 and 8. [0018] In the following, a case in which the charging type vacuum cleaner 400 that can be used for switching between the upright type and the hand type can be used as an example is described as an example. However, it is also applicable to only It is an upright type or an electric vacuum cleaner of various forms such as a hand-held type. [0019] FIG. 7 is a view showing an electric vacuum cleaner equipped with the electric blower of the present embodiment, (a) is a perspective view when used as an upright type, and (b) is a vacuum cleaner as a hand-held type. A side view to use. [0020] As shown in FIG. 7(a), the electric vacuum cleaner 400 is provided with a cleaner body 409 that houses a dust collecting chamber 401 that collects dust as dust and generates a suction airflow required for dust collection. The electric blower 200 (FIG. 1) and the telescopic tube 402 are freely extendable with respect to the cleaner body 409; and an upright grip 403 is disposed at one end of the telescoping tube 402; and the switch portion 404 It is disposed at the upright grip 403 and is configured to open and close the power of the electric blower 200. [0021] The electric vacuum cleaner 400 shown in FIG. 7(a) is in an upright state, the extension tube 402 is extended, and the upright grip 403 is fixed to the opposite side of the cleaner body 409 via the extension tube 402. status. Further, at the other end of the cleaner body 409, a mouthpiece 405 is attached, and the cleaner body 409 and the mouthpiece 405 are connected by a connecting portion 406. [0022] The electric vacuum cleaner 400 shown in FIG. 7(b) is in a hand-held state, and the extension tube 402 is housed in the cleaner body 409, and the upright grip 403 is connected to the cleaner body 409 via the extension tube 402. The state of approach. In this state, by using the hand grip 407 disposed at the cleaner body 409 instead of using the upright grip 403, it is easy to perform the sweep in the hand-held state. Further, at the other end portion of the cleaner body 409, a mouthpiece (gap nozzle) 408 is attached, and the cleaner body 409 and the mouthpiece body 408 are connected by the connecting portion 406. In the above-described electric vacuum cleaner 400, by operating the switch portion 404 of the upright grip 403, the electric blower 200 (refer to FIG. 1) housed in the cleaner body 409 is driven to generate a suction airflow. Thereafter, dust is sucked from the mouthpieces 405 and 408, and dust is collected in the dust collecting chamber 401 of the cleaner body 409 through the connecting portion 406. 8 is a longitudinal cross-sectional view of the cleaner body on which the electric blower of the embodiment is mounted. In addition, FIG. 8 is in a state of being in a hand-held state, and is a state in which the mouthpiece body 408 is detached from the cleaner body 409. As shown in FIG. 8, generally, inside the cleaner body 409, the electric blower 200 which generate|occur|produces an attraction force, the battery unit 410 which supplies electric power to the electric blower 200, and the drive circuit 411 are provided. The air taken in from the mouthpieces 405 and 408 (refer to Figs. 6(a) and (b)) is sent to the set disposed in front of the electric blower 200 through the flow path provided in the cleaner body 409. In the dust chamber 401, dust is collected in the dust collecting chamber 401. Further, the air after the dust is separated in the dust collecting chamber 401 is discharged from the exhaust port (not shown) formed in the cleaner body 409 by the electric blower 200 and the driving circuit 411 to external. [0024] Next, the electric blower 200 will be described with reference to an external view of the electric blower shown in FIG. 1(a) and a longitudinal sectional view of the electric blower shown in (b). The electric blower 200 is roughly divided into a blower unit 201 and a motor unit 202. The blower unit 201 is provided with a slab 2 by a centrifugal fan 1 as a rotary wing, and a motor unit 202 inside the centrifugal fan 1 and is disposed in the centrifugal fan 1 The outer peripheral portion is configured by a resin fan case 3 in which a diffusion vane 23 is disposed to accommodate a diffusion vane. The zoning plate 2 is formed by the inner surface of the fan case 3 and the outer peripheral end 2a of the reticle 2 to form a ring flow path 25 for allowing air to flow into the motor unit 202. Above the fan case 3, an air suction port 4 is provided. The centrifugal fan blade 1 is made of a thermoplastic resin and is directly connected to the rotating shaft 5. Here, in the present embodiment, the centrifugal fan blade 1 as a rotary wing is press-fitted and fixed to the rotary shaft 5, but a screw may be provided at the end of the rotary shaft 5 and fixed. A nut is used to fix the centrifugal fan blade 1. The motor unit 202 is configured by a rotor center 7 that is fixed to a rotating shaft 5 housed in the casing 6, and a stator center 8 that is fixed to the casing 6. Around the stator center 8, the stator windings 9 are wound and form a phase winding together. The phase winding is electrically connected to the drive circuit 109 provided at the electric blower 200. The rotor center 7 is formed at the end of the rotating shaft 5 opposite to the end to which the centrifugal fan 1 is fixed, and is made of a rare earth bonded magnet. A rare earth-based bonded magnet is prepared by mixing a rare earth-based magnetic powder with an organic binder. As the rare earth-based bonded magnet, for example, neodymium iron magnetite or neodymium magnet can be used. The rotor center 7 is integrally formed at the rotating shaft 5. Further, in the present embodiment, although a permanent magnet is used in the center 7 of the rotor, it is not limited thereto, and a reluctance motor or the like which is one of the brushless motors may be used. [0028] Between the centrifugal fan car 1 and the rotor center 7, bearings 10 and 11 are provided, and the rotating shaft 5 is rotatably supported. A spring 12 is disposed between the bearing 10 and the bearing 11 in a compressed state, and a preload is applied to the bearing 10 and the bearing 11. The bearings 10, 11 and the spring 12 are enclosed in a bearing housing 13. The casing 6 is made of synthetic resin and has a support portion 14 for fixing the bearing cover 13. At the outer periphery of the bearing cover 13, a plurality of cooling fins 13a having a long side in the direction of the rotation axis of the cooling radiators for the bearings 10 and 11 are provided. The bearing cover 13 is made of a non-magnetic metal material and is integrated with the resin case 6 by insert molding. [0029] At the end of the support portion 14 of the resin case 6, a screw hole 15 extending in the direction of the rotation axis is formed. The fixing screw 16 can be screwed at the screw hole 15, and the stile 2 is fixedly disposed at the resin case 6 by the screwing of the fixing screw 16. [0030] A ring flow path 25 is formed between the inner surface 3a of the fan case 3 and the outer peripheral end 2a of the reticle 2. At the zoning plate 2, the diffusion wings 23 are provided with a plurality of pieces in the circumferential direction with the rotation shaft 5 as a center. Further, the area of the annular flow path formed between the inner surface 3a of the fan casing 3 and the outer peripheral end 2a of the reticle 2 is set to be larger than the outlet area of the centrifugal fan car 1. Thereby, the increase in the flow velocity at the annular flow path portion and the increase in the loss at the annular flow path portion are suppressed. Moreover, the diffusion wing 23 of the zoning plate 2 is at the design point so that the airflow flowing from the centrifugal fan blade 1 and the wing inlet angle are slightly coincident with each other, and the rotation direction of the airflow is made by the diffusion wing 23 Reduce, by this, to improve the diffuser effect, and increase the efficiency of the blower. Further, by arranging the zoning plate 2 on the side of the motor portion 202 which is inside the centrifugal fan blade 1, the airflow in the motor portion 202 caused by the centrifugal fan blade 1 can be obtained. The disturbance is suppressed to suppress an increase in the flow path loss of the motor unit 202, and the disk friction loss of the centrifugal fan car 1 can be reduced. [0032] At the casing 6, an opening 17 for allowing air to flow into the casing 6 and an exhaust port 18 for discharging air to the outside of the electric blower 200 are provided. The stator center 8 disposed at the end of the casing 6 is fixed to the casing 6 by a fixing screw 19. [0033] Next, the flow operation of the air in the electric blower 200 will be described. When the motor unit 202 is driven to rotate the centrifugal fan 1 that is a rotary wing, the air flows in from the air intake port 4 of the fan case 3 and flows into the centrifugal fan car 1. The inflowing air is boosted and accelerated in the centrifugal fan car 1, and flows out from the outer periphery of the centrifugal fan car 1. The airflow that has flowed out of the centrifugal fan blade 1 flows along the wing as it passes through the diffusion wing 23, and the velocity component of the airflow in the rotational direction is reduced. The airflow flowing out of the diffuser 23 flows into the motor unit 202 from the annular flow path 25 formed by the inner surface of the fan casing 3 and the outer peripheral end 2a of the reticle 2. [0034] The air that has flowed into the motor unit 202 flows into the interior of the casing 6 from the opening 17 of the casing 6. By the inflow of air, the cooling fins 13a of the bearing cover 13 are cooled, and the bearings 10, 11 are cooled via the bearing cover 13. Further, the rotor center 7, the stator center 8, and the stator winding 9 are cooled and discharged to the outside. Thereby, the parts in the casing 6 are cooled. A part of the airflow that has flowed into the casing 6 is discharged to the outside from the exhaust port 18 of the casing 6. In addition, the number of operating revolutions of the motor is 80,000 to 100,000 min ^-1 . [0035] At the end of the fan case 3, a projection 20 is provided, and a mounting hole 21 for fixing the fan case 3 to the casing 6 is provided. A claw-like projection 22 is provided at an end portion of the casing 6 on the side of the blower portion 201, and is fitted to the mounting hole 21 of the fan casing 3. [0036] Next, the blower unit 201 of the present embodiment will be described with reference to FIGS. 2 to 3. Figure 2 (a) is a perspective view of a centrifugal fan car of one of the embodiments caused by the present invention, (b) is a sectional view of a centrifugal fan blade, and Figure 3 is one of the present invention. The blower portion in the embodiment is a cross-sectional view taken along line AA of the electric blower of Fig. 1(a). [0037] First, a centrifugal fan blade 1 as a rotary wing in one of the embodiments of the present invention will be described with reference to FIG. The centrifugal fan car 1 of one of the embodiments of the present invention is composed of a shroud plate 33 and a hub plate 26 and a plurality of blades 27. The hub plate 26 and the blade 27 are integrally formed by a thermoplastic resin. The shroud plate 33 made of a thermoplastic resin is formed with an annular suction opening 28 for sucking air at the center portion. [0038] At the flow surface of the shroud plate 33, a concave groove 29 is formed at a position corresponding to the blade 27, and is extended to the outer diameter side. A through hole 30 is provided in the concave groove 29. At the center of the hub plate 26, a boss 31 having a convex shape for inserting and fixing the rotary shaft 5 is formed. The blades 27 integrally formed with the hub plate 26 are provided at equal intervals in the circumferential direction, and are provided with blades that are retracted toward the rotation direction from the inner diameter side toward the outer side in the radial direction. shape. The boss 31 is formed with a boss curved surface 31a so as to face the radial direction from the axial direction. At the upper surface of the blade 27, a projecting claw 32 and a rib for welding are formed. The protruding claw 32 of the blade 27 is engaged with the through hole 30 of the shield plate 33, and the concave groove 29 of the shield plate 33 is engaged with the blade 27, and the claw 32 and the rib are welded. The centrifugal fan blade 1 is formed by bonding by fusion processing. In addition, although the fan blades in the figure are displayed in eight pieces, they may be other numbers. Since the fusion rib is melted in the concave groove 29, the volume of the fusion rib is made smaller than the volume of the gap when the blade 27 is inserted into the concave groove 29. In other words, it is possible to suppress the situation in which the molten resin material is oozing out into the flow path of the centrifugal fan car 1. Further, since the ribs of the blade 27 are melted and melted with the shroud plate 33, it is possible to prevent the flow that leaks between the blades 27. In the present embodiment, the through hole 30 is provided in the shield plate 33 in order to position the shield plate 33 and the blade 27, but the present invention is not limited thereto, and may be omitted. The shape of the recessed portion may be any shape as long as it can be fitted to the claw 32 of the blade 27 and the shield plate 33 and the blade 27 are positioned. Further, a convex portion 26a is provided on the outer circumference of the blade 27 of the hub plate 26, and the centrifugal fan blade 1 is rotated to cut the convex portion 26a, thereby performing balance correction. As a result, the degree of imbalance of the centrifugal fan car 1 can be reduced, and vibration and noise can be reduced. In addition, although FIG. 2 is shown for a closed type centrifugal fan blade provided with a shield plate 33, an open type centrifugal blade car which does not have the cover plate 33 or an irrelevant shield may be used. The inclined surface fan blade is inclined so that the hub curved surface 31a covers the outer peripheral portion of the blade car toward the axial direction. [0040] Next, a blower 201 according to one embodiment of the present invention will be described with reference to FIGS. 1 and 3. The blower 201 in one of the embodiments of the present invention is provided with 15 diffusing fins 23 which are disposed at equal intervals in the circumferential direction at the outer peripheral portion of the centrifugal fan blade 1 which is a rotary wing. The shape of the diffusion wing 23 in the axial direction is formed from the zoning plate 2 toward the fan case, and is integrally formed with the reticle 2 (Fig. 4). The inlet height b3 of the diffuser (the fan case side of the reticle 2 and the axial dimension of the hub of the diffuser wing and the fan case 3b) is set to be such that it flows with the outer diameter of the impeller. The ratio b3/b2 between the road heights (outlet heights b2) is 1.16, so that the axial position of the diffuser reticle and the impeller hub plate slightly coincide with each other. As a result, the deceleration effect of the airflow at the inlet portion of the diffuser is improved and the efficiency is increased, and the performance variation due to the variation in the position in the impeller axis direction which is likely to occur at the time of mass production is lowered. In addition, the ratio D3/D2 between the diffuser inlet diameter D3 and the outermost diameter D2 of the impeller is set to 1.1, and at the same time, high efficiency and low noise are achieved. [0041] Here, the shape of the diffusion wing will be described. The diffuser wing 23 has a stagger angle of about 80 degrees between the chord length and the line connecting the front edge of the diffuser and the center of rotation. This is based on the relationship between "the line connecting the trailing edge of the impeller blade to the center of the rotating shaft" and the "connection at the pressure surface of the outer edge of the blade" as shown in FIG. The blade exit angle β2 at the angle is relatively increased to achieve high efficiency due to deceleration in the diffuser. Further, when a tapered portion or a rounded portion or the like is provided at the outer edge portion of the blade, the blade exit angle at the outer edge portion other than the outermost portion other than the portion is set to Β2 can be. Further, the diffuser blade 23 is provided with a chord length C (the length from the front edge 23a of the diffuser blade 23 and the length of the trailing edge 23b) divided by the wing mounting interval is about 1 Wing shape. Further, the solidity system may be about 1 to 1.3, and if the solidity is 1 or more, the slot portion 24 is formed by the adjacent wing, and the wing portion 24 is formed to be adjacent to each other. The center of the chord of the wing has a feature closer to the side of the trailing edge 23b, and the efficiency can be improved. [0043] Moreover, the maximum thickness ratio t/C obtained by dividing the maximum thickness t of the diffusion wing by the diffusion chord length C is set to about 8%, and the thickness which is easy to be formed at the time of mass production is simultaneously achieved and High efficiency due to a decrease in the resistance coefficient. In addition, the maximum thickness ratio is ideally 6 to 12%. In this case, even when the operation is performed in an unstable phenomenon such as a rotational stall which is likely to occur under the operating conditions on the low air volume side compared to the design point air volume, it is possible to prevent the occurrence of the repeated stress ( Repeated stress) caused damage to the wing. In addition, when the chord length is 9 mm or more, if the chord length is 9 mm or more, it is assumed that the maximum thickness of the blade can be 0.7 mm or more. It can prevent the generation of hairs during molding and can reduce the performance variation in mass production. Further, the minimum thickness of the diffusion fins 23 is set to be 4% or more of the chord length, and the resin defect at the time of molding is prevented. [0044] The diffusion wings 23, which are illustrated in FIG. 4, are integrally formed with the reticle 2 and are in contact with the fan casing 3 located at the opposite side of the reticle 2. In addition, at the contact surface 3b of the fan case 3 and the diffusion wing 23, contact is made by using a soft material (for example, synthetic rubber) different from the sealing material, so that the leakage airflow between the diffusion wings can be made. It is suppressed and can be made more efficient. Further, as shown in Fig. 1, the flow path of the diffuser fin formed by the fan case 3 and the reticle 2 is not horizontal but is a flow path which is inclined toward the axial direction. As a result, the loss when the airflow sent from the diffusion vane 23 collides with the inner wall 3a of the fan case is reduced, and the efficiency is improved. [0045] Here, in FIG. 5, the influence of the efficiency of the electric blower due to the solidity of the diffuser is shown. In addition, the test result is the test result in the case where the impeller and the diffuser inlet angle are the same. That is, the difference between the diffuser having the solidity close to the prior art and the blower of the present embodiment having the diffusing fins 23 is shown. In addition, in Fig. 5, the horizontal axis represents the actual degree, and the vertical axis represents the experimental result of the efficiency of the electric blower. Here, the efficiency of the electric blower of FIG. 5 is defined by dividing the "product of the suction volume flow rate and the compressibility coefficient and the blower pressure" by the "input of the electric blower". According to Fig. 5, it can be seen that the efficiency of the blower having a solidity of about 1 to 1.3 is high, and in the case of a diffuser of 0.9 or less as in the prior art, the blower efficiency is lowered. This is because the chord length is short, so that the deceleration caused by the wing cannot be reduced, that is, the velocity component in the rotational direction of the airflow flowing from the impeller cannot be reduced. Further, if the solidity is too large, the frictional loss of the wing is increased, so that the efficiency of the blower is lowered. [0046] Next, in FIG. 6, the effect of the electric blower efficiency of the diffuser and the influence of the wing passage frequency noise of the diffuser is changed in order to fix the solidity of the diffuser. In addition, the test result is a test result in the case where the impeller and the diffuser inlet angle are matched to a solidity of about 1. Further, the number of rotations of the operation is about 84,000 min ^-1 , and the primary component of the wing passage frequency noise is about 11 kHz. In Fig. 6, the horizontal axis represents the number of diffusion wings, and the vertical axis represents the experimental results of the efficiency of the electric blower and the primary component of the wing passage frequency noise. According to Fig. 6, it can be seen that if the number of diffusion wings is set to 15, the noise is the lowest and the blower efficiency is high. In addition, when the number of the diffusing fins is 15 or 17, the amount of protrusion (significant amount) of the frequency band centering on the spoiler noise of the frequency of the first component of the frequency noise is close to the wing. Below 6dB, it helps with the improvement of sound quality. In other words, it is known that in order to achieve high efficiency and low noise at the same time, it is desirable that the solidity is about 1 to 1.3 and the number of diffusing fins is 15 to 17. [0047] According to the electric blower 200 of the embodiment described above, by providing a diffuser having a solidity of about 1 to 1.3 and a number of diffusing fins of 15 to 17, it is possible to The velocity component in the direction of rotation of the airflow flowing out of the diffuser blade 23 is reduced to obtain an efficient diffuser effect, and the significant amount of the wing passage frequency noise is 6 dB or less, which is small, and becomes low noise and sound quality is good. It is possible to suppress the whiskers at the time of molding, and to obtain an electric blower capable of reducing the variation in mass production performance. Further, by using the above-described electric blower, it is possible to provide a small-sized, low-speed operation sound that is excellent in sound quality in a wide air volume region, and which has a small sound. Further, the present invention is not limited to the above embodiments, and various modifications are also included. For example, the above-described embodiments are described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not limited to all of the constituents including the above description. Additional, clipping, or replacement of other components may be made for a part of the configuration of the embodiment.

[0049]

1‧‧‧ centrifugal fan blade

2‧‧‧Districts

2a‧‧‧ outside the perimeter of the slab

3‧‧‧Fan box

3a‧‧‧ inside the fan box

3b‧‧‧Face of the inner surface of the fan box

4‧‧‧Air intake

5‧‧‧Rotary axis

5a‧‧‧Rotary axis center

6‧‧‧Shell

7‧‧‧Rotor Center

8‧‧‧ Stator Center

9‧‧‧Spiral winding

10‧‧‧ bearing

11‧‧‧ bearing

12‧‧‧ Spring

13‧‧‧ bearing cover

13a‧‧‧ Cooling fins

14‧‧‧Support Department

15‧‧‧ screw holes

16‧‧‧ screws

17‧‧‧ openings

18‧‧‧Exhaust port

19‧‧‧ Stator center fixing screws

20‧‧‧ Protrusion

21‧‧‧Installation holes

22‧‧‧ claw-like protrusion

23‧‧‧Diffuse wings

23a‧‧‧ Front edge of the diffuser

23b‧‧‧The trailing edge of the diffusion wing

24‧‧‧wing joint

25‧‧‧Circular flow path

26‧‧‧ hub plate

26a‧‧‧ convex

27‧‧‧ fan leaves

28‧‧‧Inhalation opening

29‧‧‧ concave groove

30‧‧‧through holes

31‧‧‧Seat

31a‧‧‧ convex surface

32‧‧‧ claws

33‧‧‧ Shield

200‧‧‧Electric blower

201‧‧‧Air blower department

202‧‧‧Electric Motor Department

400‧‧‧ electric vacuum cleaner body

401‧‧‧dust room

402‧‧‧ telescopic tube

403‧‧‧Upright grip

404‧‧‧Switch Department

405‧‧‧Sucking body

406‧‧‧Connecting Department

407‧‧‧Hand grip

408‧‧‧Sucking body (gap nozzle)

409‧‧‧ vacuum cleaner body

410‧‧‧ battery unit

411‧‧‧Drive circuit

[ Fig. 1 (a)] is an external view of an electric blower according to a first embodiment of the present invention. Fig. 1(b) is a longitudinal sectional view showing an electric blower according to a first embodiment of the present invention. Fig. 2 (a) is a perspective view of a centrifugal fan blade according to a first embodiment of the present invention, and (b) is a longitudinal sectional view of a centrifugal fan blade. Fig. 3 is a cross-sectional view taken along the line A-A of the electric blower of Fig. 1(a), showing a portion of the blower unit according to the first embodiment of the present invention. Fig. 4 is a view showing a diffusing portion of the air blower in the first embodiment of the present invention. Fig. 5 is a comparison diagram showing the efficiency of an electric blower in which the blowers of the embodiments of the present invention are combined with an electric motor and tested. Fig. 6 is a graph comparing the air blower in the embodiment of the present invention and the noise of the electric blower due to the number of diffusing wings and the noise of the first pass component of the wing passing frequency. Fig. 7 is a perspective view of an electric vacuum cleaner to which an electric blower according to an embodiment of the present invention is applied. Fig. 8 is a cross-sectional view showing the cleaner body in the electric vacuum cleaner of Fig. 7.

Claims (5)

An electric blower and an electric vacuum cleaner including an electric blower, comprising: a motor having a rotor and a stator; and a housing having one end opened and accommodating the motor; and a rotating shaft is disposed on a rotor; and a rotating wing fixed to the rotating shaft; and a partition plate disposed at the motor side of the rotating wing; and a plurality of diffusing wings disposed at an opening of the housing a peripheral portion of the rotary wing at the side; and a fan casing covering the diffusion wing, wherein the diffusion wing forms a throat portion by abutting the wing, and the throat portion is formed on the adjacent wing At the center of the chord length and at the trailing edge side, the number of the diffusing wings is 15 to 17. An electric blower and an electric vacuum cleaner including an electric blower, comprising: a motor having a rotor and a stator; and a housing having one end opened and accommodating the motor; and a rotating shaft is disposed on a rotor; and a rotating wing fixed to the rotating shaft; and a partition plate disposed at the motor side of the rotating wing; and a plurality of diffusing wings disposed at an opening of the housing The outer peripheral portion of the rotating wing at the side; and the fan casing cover the diffusing wing, and the solidity of the diffusing wing is 1 to 1.2, and the diffusing wing is 15 to 17. The electric blower according to the first or second aspect of the invention, and the electric vacuum cleaner provided with the electric blower, wherein the maximum thickness ratio of the diffuser is formed to be 6 to 12% of the chord length. The electric blower according to the first or second aspect of the invention, and the electric vacuum cleaner provided with the electric blower, wherein the inlet height of the diffuser is larger than the height of the impeller outlet. The electric blower according to any one of claims 1 to 5, wherein the diffuser is provided in a flow path in a direction of the axial direction, and an electric vacuum cleaner including the electric blower.