TWI400392B - Electric blower and electric vacuum cleaner with the electric blower - Google Patents

Description

Electric blower and electric vacuum cleaner having the same

The present invention relates to an electric blower and an electric vacuum cleaner provided therewith.

A conventional electric blower is disclosed in, for example, Patent Document 1 (JP-A-54-105307).

In the electric blower of Patent Document 1, a partition plate is provided on the back side of the vane wheel (centrifugal fan), and a diffuser vane (diffuser vane) is provided on the outer peripheral side of the front vane wheel of the partition plate. Here, the wings of the diffuser are provided with slits from the front side (reverse partition side).

Further, other conventional techniques are disclosed in, for example, Patent Document 2 (Japanese Laid-Open Patent Publication No. Hei 8-242553). In the electric blower of Patent Document 2, an air guide (diffuser) is provided on the outer peripheral side of the impeller (centrifugal fan), and one or a plurality of through holes are provided in the air guide fin portion.

[Patent Document 1] JP-A-54-105307

[Patent Document 2] Japanese Patent Laid-Open No. Hei 8-242553

In Patent Document 1, a slit is provided in the wing of the diffuser from the front side (reverse partition side) to reduce noise. The diffuser is provided to decelerate the flow from the centrifugal fan to return the dynamic pressure to the static pressure. However, the flow from the slit in Patent Document 1 hinders the deceleration of the main flow flowing between the wings of the diffuser, and the pressure recovery is insufficient. The problem is that the efficiency of the blower is reduced.

In addition, in Patent Document 2, one or a plurality of through holes are provided in the centrifugal fan. However, as in Patent Document 1, the flow from the through holes hinders the deceleration of the main flow flowing between the wings of the diffuser, and the pressure recovery cannot be performed. It is fully carried out, and there is a problem that the efficiency of the blower is lowered.

The positions of the through holes relating to the efficiency of the blower in Patent Documents 1 and 2 are not considered at all.

An object of the present invention is to solve the above problems and to provide an electric blower and an electric vacuum cleaner including the same, which can reduce the noise of the blower and improve the efficiency of the blower.

In order to achieve the above object, an electric blower according to the present invention includes: a motor provided with a rotating member and a fixing member; and a casing having an opening at one end and housing the motor therein, and a rotating shaft provided to the rotating member and fixed a centrifugal fan disposed on the rotating shaft, a partition plate disposed on a back side of the centrifugal fan, and a diffuser disposed on an outer circumferential side of the centrifugal fan on a front side of the partition plate, and disposed on the centrifugal fan a return guide on the rear side of the partition plate, and a fan casing provided on the opening side of the outer casing to cover the centrifugal fan, the diffuser, and the return guide, wherein the diffuser is provided with a plurality of diffusers The wing has a through hole that rises from the partition plate in the diffuser blade of at least a part of the plurality of diffuser wings.

According to the present invention, it is possible to provide an electric blower and an electric vacuum cleaner including the electric blower, which can reduce the noise of the blower and improve the efficiency of the blower.

Fig. 12 is a perspective view showing the appearance of an electric vacuum cleaner according to an embodiment of the present invention. Reference numeral 101 denotes a cleaner body for accommodating a dust collecting chamber for dust collection and an electric blower for collecting a suction airflow required for dust collection, and 102 is a tube having one end connected to the cleaner body 101 via a pipe joint 102a, and 103 is one end and The hand operating portion 104 connected to the other end of the tube 102 is an extension pipe having one end connected to the other end of the hand operation portion 103, and 105 is a mouthpiece body connected to the other end of the extension pipe 104. 103a is a switch unit that performs a switch of the electric blower provided at the hand operation unit 103.

Next, the structure of the cleaner body 101 is shown using FIG. Figure 11 is a cross-sectional view showing the cleaner body of an embodiment of the present invention. In Fig. 11, reference numeral 110 denotes a dust collecting chamber formed on the front side of the cleaner body 101, 111 is a dust collecting bag for collecting dust in the dust collecting chamber 110, and 112 is an electric blower chamber formed on the rear side of the cleaner body 101. 113 is an electric blower that is placed in the electric blower chamber 112 to generate an attraction force. 114 is an anti-vibration rubber that supports the electric blower 113, and 115 is a filter unit that is disposed between the dust collecting chamber and the electric blower 113.

In the above configuration, when the switch unit 103a of the hand operation unit 103 is operated, the electric blower 113 housed in the cleaner body 101 is operated to generate a suction airflow. In addition, the dust is sucked from the mouthpiece 105, and is collected by the dust collecting bag 111 disposed in the dust collecting chamber 110 of the cleaner body 101 by the extension pipe 104, the hand operation unit 103, and the pipe 102. In the present embodiment, the vacuum cleaner of the dust collecting bag 111 is disposed in the dust collecting chamber 110. However, the dust collecting chamber 110 may be installed by the cyclone dust collecting portion that is centrifugally separated.

Next, the structure of the electric blower 113 will be described using FIG. Fig. 10 is a longitudinal sectional view showing an electric blower 113 according to an embodiment of the present invention. The electric blower 113 is composed of a blower unit 11 and a motor unit 12.

The motor unit 12 is a motor case formed by an outer casing 13 that is opened at one end and an end bracket 14 that is disposed on the opening side of the outer casing 13. The rotary shaft 15 of the rotary member 16 is rotatably supported by the reverse opening side of the outer casing 13 and the end bracket 14, and the rotary shaft 16 is attached to the rotary shaft 15. A fixing member 17 is disposed on the outer peripheral side of the rotor 16 . The supply of electric power to the rotor 16 is transmitted by the brush 18 and the commutator 19 in contact therewith. A rotor 16 , a fixture 17 , and a brush 18 are housed in the casing 13 .

The blower unit 11 is a centrifugal fan 20 that is fixed to the rotating shaft 15 and includes a suction port 20a, a diffuser 21 that is disposed on the outer peripheral side of the centrifugal fan 20, and a partition plate 23 for the diffuser 21. The return guide 25 disposed facing the ground is housed in the fan casing 26 and configured. The fan casing 26 is disposed on the opening side of the casing 13, and covers the centrifugal fan 20, the diffuser 21, and the return guide 25. The partition plate 23 is located on the back side (reverse suction port side) of the centrifugal fan 20. A diffuser 21 is disposed on the front side of the partition plate 23, and a return guide 25 is disposed on the rear side of the partition plate 23. 27 is an annular plate disposed on the counter partition plate side of the diffuser 21.

In this configuration, the air flowing in from the blower inlet 10 is first boosted and increased by the centrifugal fan 20. Thereafter, the flow that the diffuser 21 passes is slightly turned by 180° through the curved flow path 24, and flows toward the return guide 25, but in this process, the flow is decelerated, and the pressure of the portion rises. The flow of the return guide 25 passes through the inside of the casing 13 of the motor, and the rotating member 16, the fixing member 17, the brush 18, the commutator 19, and the like are cooled and exhausted.

The structure of the diffuser 21 is explained in Fig. 9. Fig. 9 is a view showing the diffuser 21 from the axial direction of the rotary shaft 15, that is, the side of the blower inlet 10. As shown in Fig. 9, the diffuser 21 has a plurality of diffuser vanes 22 disposed on the front side of the partition plate 23, and the wind discharged from the centrifugal fan 20 passes through the adjacent diffuser vanes 22. between. Here, the diffuser vane 22 has a circular arc shape, and is formed from the inlet side of the flow across the outlet side and the interval between the adjacent diffuser vanes 22, and the wind is passed therethrough. The flow is slowed down and the pressure is restored.

The trailing edge of the diffuser vane 22 is located adjacent the fan casing 26. Between the trailing edge of the diffuser vane 22 and the fan casing 26, a triangular window 51 having a substantially triangular shape cut away toward the inside of the diffuser 21 is formed. The wind blown from between the diffuser blades 22 is turned in the vertical direction by the triangular window 51, and flows toward the return guide 25 side. Here, the diffuser side 52 defines the convex side 52 and the concave side 53 as shown in the figure, and the area surrounded by the adjacent wings in the inter-wing flow path is defined as the overlapping portion 54, and only the outlet side of the flap facing the sheet side The field is defined as the outlet side half opening 55.

Next, the flow between the diffuser blades 22 in the diffuser 21 will be described using Figs. 7 and 8. Fig. 7 is a partially enlarged view of the blower unit 11, and Fig. 8 is a cross-sectional view of the diffuser 21 in Fig. 7. Fig. 8(a) is a cross-sectional view taken along line A-A of Fig. 7, Fig. 8(b) is a cross-sectional view taken along line B-B of Fig. 7, and Fig. 8(c) is a cross-sectional view taken along line C-C of Fig. 7.

In FIGS. 7 and 8, the side of the partition plate 23 is defined as a hub side, and the side of the suction port 20a of the centrifugal fan 20 is defined as a cover side. Therefore, Fig. 8(a) shows the flow of wind between the diffuser blades 22 in the hub side, and Fig. 8(c) shows the flow of wind between the diffuser blades 22 in the cover side, Fig. 8 (Fig. 8) b) is a flow of wind between the diffuser blades 22 in the center portion in the height direction of the diffuser vanes 22 in the middle between the hub side and the cover side.

As is apparent from Fig. 8, when the hub-side main flow 81, the central cross-section main flow 82, and the cover-side main flow 83 are seen, the main flow of the wind flowing between the diffuser blades 22 is biased toward the concave side of the diffuser blade 22, and the speed is fast. Flow concentration. Conversely, the interface layer is developed in the convex side, and becomes a slow flow. From this, it can be seen that an effective flow path expansion cannot be achieved between the diffuser blades 22, and the pressure recovery is insufficient. This tendency is particularly remarkable in the hub side shown in Fig. 8(a), and gradually decreases as it goes from the center portion toward the cover side. The inventors have found that the turbulent flow of the diffuser wings 22 differs in the height direction. In this way, since the effective flow path is not expanded between the diffuser blades 22, the pressure recovery is insufficient, so that the blower noise occurs and the efficiency of the blower is lowered. In order to improve, there is a need to improve the flow especially on the hub side. Hereinafter, the means for solving will be described using Figs. 1 to 6 .

Fig. 1 is an overall perspective view of a diffuser 21 according to an embodiment of the present invention, and Fig. 2 is an enlarged view of a portion of the diffuser 21 according to an embodiment of the present invention as seen from the direction of the rotary shaft 15 of the motor. The equation for the position of the through hole 40 of the diffuser 21 according to the embodiment of the present invention is obtained.

In the first drawing, a plurality of diffuser blades 22 rising from the partition plate 23 are provided in the partition plate 23. Further, in the diffuser vane 22, a through hole 40 rising from the partition plate 23 up to a predetermined height is formed. The through hole 40 is formed to penetrate between the adjacent flow paths 56. That is, the through hole 40 is formed on the hub side. Further, the through hole 40 is located in the vicinity of the triangular window 51 (notched portion) for changing the flow direction toward the return guide 25.

Next, the flow between the diffuser blades 22 in the diffuser 21 when the through holes 40 are provided will be described using FIG. Fig. 4 is a cross-sectional view of the diffuser 21 in Fig. 7. Fig. 4(a) is a cross-sectional view taken along line A-A of Fig. 7, Fig. 4(b) is a cross-sectional view taken along line B-B of Fig. 7, and Fig. 4(c) is a cross-sectional view taken along line C-C of Fig. 7.

In the fourth diagram (a), in the case where the through hole 40 is provided, the leakage flow is generated from the convex surface side of the blade toward the concave surface side through the through hole 40. Therefore, in the hub surface side where the through hole 40 exists, the boundary layer having a slow speed in Fig. 8(a) is sucked toward the opposite side (concave side) of the blade, and the flow is sucked out. It is turning to the left of the drawing. Moreover, an effective flow path can be expanded between the diffuser wings 22, and the pressure can be recovered. Further, the flow in the center cross section in Fig. 4(b) and the cover side in Fig. 4(c) is not as the flow on the hub side of Fig. 4(a), but is deflected by the flow in the hub side. The effect of the effective flow path expansion between the diffuser wings 22 is achieved. As described above, in the present embodiment, by providing the through hole 40 on the hub side, the effective flow path between the diffuser blades 22 can be expanded on the hub side, the center portion, and the cover side, and the pressure can be restored. Thereby, noise can be reduced and the efficiency of the blower can be improved.

Further, as in the present embodiment, when the diffuser 21 and the return guide 25 are separated and the triangular window 51 (notched portion) is present therebetween, since the convex side of the wing is widened by the triangular window, By diverting the hub side flow in this wide area, it is possible to achieve a smooth curved flow.

The through hole 40 is opened before the inflow of the triangular window 51 which is the curved portion. However, the flow through the through hole 40 causes the inlet side (the convex side) to be more negatively pressed than the surrounding due to the suction force. Therefore, there is an effect that the flow between the wings is curved toward the through hole 40, and therefore there is an effect of supporting the curved flow to the connection of the return guide 25.

When the effective enlarged flow path area is generated by the third-order deflection of the main flow flowing in the diffuser as described above, the blower efficiency can be improved by the smooth curved flow guided from the diffuser toward the return.

This embodiment can be confirmed experimentally by considering the above-described mechanism, in particular, by setting the following conditions for the expectation of further effects. That is, the height (h) of the through hole 40 as shown in Fig. 1 is 1/2 or less of the height (H) of the diffuser, that is, h ≦ H / 2 is preferable. The height of these is measured at the radial position of the through hole 40. Further, although the shape of the through hole 40 is rectangular in the first drawing, the shape is not limited thereto, and other shapes such as a trapezoidal shape and a circular shape may be used. Further, in FIG. 2, the perpendicular line perpendicularly intersecting the wiring (a) in the through hole 40 of the diffuser blade 22 is (b), and the angular difference of the center line of the perpendicular line (b) and the through hole 40 is defined as Through hole angle difference (θ). In the present embodiment, the through hole angle difference (θ) is 0° ≦ θ ≦ 45°. By setting this angle, the leakage flow through the through hole 40 and the merge of the main flow become smooth.

Next, using the third drawing, the position of the through hole 40 of the diffuser 21 is obtained. When the position of the through hole 40 is obtained, the technique disclosed in, for example, Japanese Patent No. 3510107 can be used.

The through hole 40 formed in the diffuser blade 22 is formed at a position 62 from the outlet end surface 61 of the overlapping portion 54 (Fig. 9) of the diffuser blade 22 at a distance δ from the side of the outlet side half opening portion 55 (Fig. 9). The diffuser wing 22 faces between them. The correction value δ is calculated from the following equation. The correction value δ is the size of the side in the rectangular cross section of the outlet of the overlapping portion air flow path, and is a and b, and when a>b, the second formula (number 1)

[Number 1]

The distance obtained.

The air flow in the diffuser 21 passes through the overlap portion 54, through the outlet half opening portion 55.

In the overlapping portion 54 of the diffuser, the sound wave generated is propagated in the flow direction of the plane wave. However, since the cross-sectional area of the flow path is discontinuously increased at the outlet end surface 30 of the overlapping portion, the acoustic impedance changes at this position. At the position where the acoustic impedance changes, the sound wave propagating along the flow until it is reflected, and this time becomes a reflected wave, and the flow propagates countercurrently toward the upstream side. Even at the position of the entrance of the overlapping portion on the upstream side, the acoustic impedance changes because the sectional area changes. Therefore, the reflected wave propagating toward the upstream side is reflected again by the entrance of the overlapping portion.

In this way, the sound wave generated by the tip end portion of the diffuser wing is a downward wave, and is reflected back and reflected again. However, the period of the reciprocating reflection coincides with the occurrence period of the incident original sound wave. Resonance occurs in the overlapping portion to increase the radio sound.

As described above, in the exit end face 30 of the overlapping portion 34, the pressure fluctuation of the sound wave is 0, that is, the knot of the fixed wave. If correctly stated, the knot of the wave is generated from the exit end face 30 of the overlapping portion 34 by the opening end correction value, that is, the position 31 of the distance δ. The above equation is a formula for obtaining the value of the open end correction value δ.

In the fifth drawing, an example of the result of experimental verification of the change in the efficiency and noise of the electric blower caused by the presence or absence of the through hole 40 and the formation position of the through hole is shown. Here, the electric blower efficiency is defined by the following formula.

Electric blower efficiency η = output / input

Output = ρ gQH

(ρ: density, g: gravitational acceleration, Q: air volume, H: pressure)

In the fifth drawing, (1) is a case where the through hole 40 is not provided, and (2) is a case where the through hole 40 is raised from the hub side up to a height of 1/2 of the diffuser blade, and (3) is The through hole 40 is cut away from the cover side toward the hub side.

First, when the efficiency of the electric blower is seen, it is apparent from Fig. 5(a) that the through hole 40 is raised from the hub side up to the diffuser as in the case (1) in which the through hole 40 is not provided. In the case (2) in which the height of 1/2 of the wing is formed, the efficiency of the electric blower is improved. In the case (3) in which the through hole 40 is cut away from the cover side toward the hub side, the efficiency of the electric blower is lowered as compared with the case (1) in which the through hole 40 is not provided. Thus, depending on the position at which the through holes 40 are formed, the efficiency of the electric blower greatly changes.

When the noise is observed, it is apparent from Fig. 5(b) that the through hole 40 is raised from the hub side and up to the diffuser wing as in the case (1) in which the through hole 40 is not provided. In the case of the formation of the height of 2 (2), the flap sound (spike) is lowered. Further, in the case (3) in which the through hole 40 is cut away from the cover side toward the hub side, the flap sound (spike) is lowered as compared with the case (1) in which the through hole 40 is not provided. Further, in the present embodiment, the case where the through hole 40 is raised from the hub side and is formed up to the height of 1/2 of the diffuser blade (2), and the case where the through hole 40 is cut away from the cover side toward the hub side (3) In the middle, the wing sounds (spikes) are almost the same. It is known that the noise is reduced, that is, the through hole 40 has a large influence in the reduction of the flap sound (spike). As can be seen, the efficiency of the electric blower varies greatly depending on the position at which the through holes 40 are formed.

As described above, in the present embodiment, since the through hole 40 is formed upright from the partition plate 23 up to the predetermined height from the partition plate 23, the noise of the blower can be reduced, and the efficiency of the electric blower can be improved.

Next, a method of manufacturing the diffuser 21, the partitioning plate 23, and the return guide 25 provided with the through holes 40 will be described using FIG. Fig. 6 is a view for explaining a method of manufacturing the diffuser 21, the partitioning plate 23, and the return guide 25 according to an embodiment of the present invention.

In Fig. 6, reference numeral 27 denotes an annular plate which is disposed on the side of the counter separator of the diffuser 21 and which is formed in a ring shape. On the side facing the partitioning plate 23 of the annular plate 27, a plurality of diffuser wings 22 are provided. Further, in the diffuser blade 22, a notch portion 22a which is a through hole 40 which is cut away from the reverse annular plate side is formed.

In the present embodiment, the annular plate 27, the diffuser vane 22, and the notch portion 22a are integrally molded of a resin or the like. When the annular plate 27, the diffuser vane 22, and the notch portion 22a are formed, it is only necessary to prepare a mold that is detached in the vertical direction, and the mold structure is simple and the productivity is improved.

Further, in the disk-shaped partitioning plate 23, a return guide 25 is provided on the side of the counter diffuser blade 22 (the rear side of the partitioning plate 23). This return guide 25 is composed of a plurality of return guide wings 25a.

In the present embodiment, the partitioning plate 23 and the return guide wing 25a are integrally molded of resin or the like. When the partition plate 23 and the return guide vane 25a are molded, the mold which is detached in the vertical direction can be prepared, and the mold structure is simple and the productivity is improved.

Next, the side of the anti-annular plate 27 of the diffuser blade 22 and the diffuser wing 22 side of the partition plate 23 (the front side of the partition plate 23) are fitted and joined. The joining method is ultrasonic welding, a bonding agent, and the like which use a high frequency to weld the resin. The joining method can be suitably selected. The through hole 40 is formed in the diffuser blade 22 by the side of the anti-annular plate 27 of the diffuser blade 22 and the diffuser blade 22 side of the partition plate 23. Further, the through hole 40 is formed in a state of being raised from the partition plate 23.

Usually, the through hole 40 is formed in a state of being raised from the partition plate 23, and it is necessary to use a slide mold for forming the through hole 40 or to perform additional processing using a drill hole or the like. In this embodiment, since the annular plate 27, the diffuser vane 22, and the notch portion 22a are integrally molded, and the partition plate 23 and the return guide vane 25a are integrally molded, these are joined together, so The through hole 40 can be formed in the diffuser vane 22 using a complicated mold.

As described above, according to the present embodiment, the electric blower and the electric vacuum cleaner including the electric blower can be provided, and the noise of the blower can be reduced, and the efficiency of the blower can be improved.

In the present embodiment, the electric blower for the electric vacuum cleaner has been described, but the present invention is not limited thereto. Can be applied to a wide variety of products as needed.

10. . . Blower inlet

11. . . Fan unit

12. . . Motor department

13. . . shell

14. . . End bracket

15. . . Rotary axis

16. . . Rotating piece

17. . . Fastener

18. . . Brush

19. . . Commutator

20. . . Centrifugal fan

20a. . . suction point

twenty one. . . Diffuser

twenty two. . . Anti-diffuser wing

22a. . . Notch

twenty three. . . Partition plate

twenty four. . . Curved flow path

25. . . Return guide

25a. . . Return guide wing

26. . . Fan housing

27. . . Anti-annular plate

30. . . Overlap exit end face

31. . . position

34. . . Overlap

40. . . Through hole

51. . . Triangular window

52. . . Convex side

53. . . Concave side

54. . . Overlap

55. . . Outlet side half opening

56. . . Flow path

61. . . Exit end face

62. . . position

81. . . Hub side mainstream

82. . . Central profile mainstream

83. . . Cover side mainstream

101. . . Vacuum cleaner body

102. . . tube

102a. . . Pipe joint

103. . . Hand operation department

103a. . . Switch section

104. . . Extension tube

105. . . Suction body

110. . . Dust chamber

111. . . Dust bag

112. . . Electric blower room

113. . . Electric blower

[Fig. 1] An overall perspective view of a diffuser 21 according to an embodiment of the present invention.

[Fig. 2] A partially enlarged view of the diffuser 21 according to the embodiment of the present invention as seen from the direction of the rotary shaft 15 of the motor.

[Fig. 3] A numerical formula for determining the position of the through hole 40 of the diffuser 21 according to the embodiment of the present invention.

[Fig. 4] A cross-sectional view of the diffuser 21 in Fig. 7.

[Fig. 5] Experimental results showing changes in efficiency and noise of the electric blower.

Fig. 6 is a view for explaining a method of manufacturing the diffuser 21, the partitioning plate 23, and the return guide 25 according to an embodiment of the present invention.

[Fig. 7] A partially enlarged view of the blower unit 11.

[Fig. 8] A cross-sectional view of the diffuser 21 in Fig. 7.

[Fig. 9] A view of the diffuser 21 from the axial direction of the rotary shaft 15, that is, the side of the blower inlet 10.

Fig. 10 is a longitudinal sectional view showing an electric blower 113 according to an embodiment of the present invention.

[Fig. 11] A cross-sectional view of a cleaner body according to an embodiment of the present invention.

[12] Fig. 12 is an external perspective view of an electric vacuum cleaner according to an embodiment of the present invention.

twenty two. . . Anti-diffuser wing

twenty three. . . Partition plate

40. . . Through hole

51. . . Triangular window

56. . . Adjacent flow path

Claims (5)

An electric blower includes: a motor provided with a rotating member and a fixing member; and a casing that is opened at one end and houses the motor therein, a rotating shaft provided on the rotating member, and a centrifugal body fixed to the rotating shaft a fan, a partition plate disposed on a back side of the centrifugal fan, a diffuser disposed on an outer peripheral side of the centrifugal fan on a front side of the partition plate, and a rear side disposed on the partition plate And a returning guide and a fan casing provided on the opening side of the casing to cover the centrifugal fan, the diffuser, and the return guide, wherein the diffuser has a plurality of diffuser wings, and the plurality of diffusers In the diffuser vane of at least a part of the wing, the opening end correction value is added to the outlet end surface of the diffuser vane of one of the overlapping portion air flow passages formed between the adjacent diffuser vanes The other diffuser vane between the positions of δ forms a through hole that rises from the partition plate; the height of the through hole is 1/2 of the height of the diffuser vane . The electric blower according to the first aspect of the invention, wherein the opening end correction value δ is a dimension of a side of a rectangular cross section of the outlet of the overlapping portion air flow passage, and is a and b, and a>b By the subtype (number 1) The distance obtained. An electric blower includes: a motor provided with a rotating member and a fixing member; and a casing that is opened at one end and houses the motor therein, a rotating shaft provided on the rotating member, and a centrifugal body fixed to the rotating shaft a fan, a partition plate disposed on a back side of the centrifugal fan, a diffuser disposed on an outer peripheral side of the centrifugal fan on a front side of the partition plate, and a reverse partition disposed on the diffuser An annular plate on the plate side, a return guide disposed on a rear side of the partition plate, and a centrifugal fan, the diffuser, the return guide, and the annular plate provided on an opening side of the outer casing a fan casing that is covered by the diffuser having a plurality of diffuser blades and integrally formed with the annular plate, and diffusing from adjacent ones of the diffuser blades of at least a portion of the plurality of diffuser blades The other of the diffuser wings between the both ends of the diffuser vanes of one of the overlapping portion air flow passages and the other end of the gap is added to the position where the opening end correction value δ is added a notch portion that is cut away from the anti-annular plate side, and the notch portion is a through hole by joining the diffuser to the partition plate; the height of the through hole is 1/1 of the height of the diffuser blade 2 or less. An electric vacuum cleaner is provided with: a dust collecting chamber and an electric air supply a vacuum cleaner body housed in the machine, a tube having one end connected to the cleaner body, a hand operation portion having one end connected to the other end of the tube, and an extension tube having one end connected to the other end of the hand operation portion, and the extension tube The suction blower body connected to the other end of the present invention is characterized in that the electric blower includes a motor provided with a rotating member and a fixing member, and an outer casing having an opening at one end and housing the electric motor therein, and a rotating member provided on the rotary member. a rotating shaft, a centrifugal fan fixed to the rotating shaft, a partition plate disposed on a back side of the centrifugal fan, and a diffuser disposed on an outer peripheral side of the centrifugal fan on a front side of the partition plate And a return guide disposed on a rear side of the partition plate, and a fan casing provided on the opening side of the casing to cover the centrifugal fan, the diffuser, and the return guide, wherein the diffuser has a plurality of a diffuser vane, in the diffuser vane of at least a portion of the plurality of diffuser vanes, in an overlapping portion of the air flow flow formed from the adjacent sides of the adjacent diffuser vanes The other diffuser vane between the outlet end surface of the diffuser vane and the position at which the opening end correction value δ is added forms a through hole that rises from the partition plate; the height of the through hole It is 1/2 or less of the height of the diffuser wing. An electric vacuum cleaner comprising: a cleaner body that houses a dust collecting chamber and an electric blower, a pipe that has one end connected to the cleaner body, and a hand operation unit that has one end connected to the other end of the pipe, and one end and the hand operation unit An extension tube connected to the other end of the extension, and the other end of the extension tube In the connected air suction blower, the electric blower includes: a motor provided with a rotating member and a fixing member; and a housing having an opening at one end and housing the motor therein, and a rotating shaft provided on the rotating member; And a centrifugal fan fixed to the rotating shaft, a partition plate disposed on a back side of the centrifugal fan, and a diffuser disposed on an outer peripheral side of the centrifugal fan on a front side of the partition plate, and a diffuser An annular plate disposed on the counter partition plate side of the diffuser, and a return guide disposed on a rear side of the partition plate, and a centrifugal fan, the diffuser, and the diffuser disposed on an opening side of the outer casing In the fan casing covered by the return guide and the annular plate, the diffuser is provided with a plurality of diffuser blades, and is integrally formed with the annular plate, and is formed in at least a part of the diffuser blades of the plurality of diffuser blades. Between the adjacent diffuser blades, the exit end face of the diffuser vane of one of the overlapping portion air flow passages is interposed between the adjacent end of the diffuser vane The side diffuser vane includes a notch portion cut away from the counter annular plate side, and the notch portion is a through hole by joining the diffuser to the partition plate; the height of the through hole is the diffuser vane The height of 1/2 or less.