vacuum cleaner

Abstract

To provide a vacuum cleaner capable of suppressing noise.SOLUTION: A vacuum cleaner includes: housing having exhaustion ports; an electric blower cover arranged inside the housing; and an electric blower stored inside the electric blower cover. The electric blower cover includes: a suction port arranged on an upstream side in an air stream direction; and a discharge port arranged on a downstream side from the suction port. The housing has an opposite wall surface opposing to the discharge port. The exhaustion ports are arranged closer to a side of the suction port than to the discharge port. An air stream discharged from the discharge port into the housing collides with the opposite wall surface, is returned to the side of the suction port, and then is discharged from the exhaustion ports to an outer side.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electric vacuum cleaner.

Background Art

[0002] An electric vacuum cleaner generates suction force by driving an electric blower provided in a housing, and sucks and removes dust on the cleaning surface. At this time, noise is generated from the electric blower. Patent Document 1 discloses a vacuum cleaner aimed at improving the noise reduction effect.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The vacuum cleaner of Patent Document 1 lengthens the exhaust passage in the cleaner body to enhance the noise reduction effect. Air sucked into the electric blower through the dust collection chamber of the cleaner body is configured to reach the exhaust portion while turning back multiple times, including problems such as an increase in pressure loss, an increase in the number of parts, an increase in assembly work, an increase in weight, an increase in cost, and an increase in size.

[0005] An object of the present invention is to provide an electric vacuum cleaner made in consideration of such circumstances.

Means for Solving the Problems

[0006] The present invention includes a housing having an exhaust port, a cylindrical electric blower cover provided in the housing, and an electric blower housed in the electric blower cover. The electric blower cover has an intake port provided on the upstream side in the direction of the airflow generated by the electric blower, and an exhaust port provided downstream of the intake port in the direction of the airflow. The housing has a wall surface facing the outlet, The exhaust port is located on the intake port side of the discharge port, The present invention provides a vacuum cleaner in which the airflow discharged into the housing from the discharge port collides with the opposing wall surface, returns to the intake port side, and is exhausted to the outside from the exhaust port. [Effects of the Invention]

[0007] According to the present invention, the vacuum cleaner can reduce noise during operation while suppressing pressure loss and an increase in the size of the housing. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of a vacuum cleaner according to the first embodiment of the present invention. [Figure 2] This is a partially perspective view of the vacuum cleaner body of the first embodiment, seen from the right rear. [Figure 3] This is a left cross-sectional view of the vacuum cleaner body of the first embodiment. [Figure 4] This is an enlarged cross-sectional view of the left side portion of the vacuum cleaner body of the first embodiment. [Figure 5] This is a cross-sectional view taken along line II in Figure 3. [Figure 6] This is a cross-sectional view taken along the line II-II in Figure 3. [Figure 7] This is a cross-sectional view taken along the line III-III in Figure 3. [Figure 8] This is a cross-sectional view taken along the line IV-IV in Figure 3. [Figure 9] This is a perspective view of the electric blower cover of the first embodiment, taken from the left rear. [Figure 10] This is a left-side cross-sectional view of the electric blower cover of the first embodiment, which houses the electric blower. [Figure 11] This is a cross-sectional view taken along the VV line in Figure 4. [Figure 12] It is a perspective view of the first vibration isolation member of the first embodiment. [Figure 13] It is a perspective view of the downstream cover in the electric blower cover of the first embodiment. [Figure 14] It is a perspective view of the electric blower of the first embodiment. [Figure 15A] It is a perspective view of the second vibration isolation member of the first embodiment. [Figure 15B] It is a perspective view of one side obtained by cutting the second vibration isolation member of FIG. 15A in half. [Figure 16] It is an explanatory view showing the third vibration isolation member provided at the lead wire opening of the downstream cover of the first embodiment. [Figure 17] It is a perspective view of the fourth vibration isolation member of FIG. 16. [Figure 18] It is a schematic left cross-sectional view of the electric blower cover of the second embodiment housing the electric blower. [Figure 19] It is a schematic left cross-sectional view of the electric blower cover of the third embodiment housing the electric blower. [Figure 20] It is a schematic left cross-sectional view of the electric blower cover of the fourth embodiment housing the electric blower. [Figure 21] It is a schematic left cross-sectional view of the electric blower cover of the fifth embodiment housing the electric blower. [Figure 22] It is a schematic left cross-sectional view of the electric blower cover of the sixth embodiment housing the electric blower.

Mode for Carrying Out the Invention

[0009] Hereinafter, this invention will be described in more detail with reference to the drawings. Note that the following description is illustrative in all respects and should not be construed as limiting this invention.

[0010] (First Embodiment) FIG. 1 is a perspective view of a vacuum cleaner according to the first embodiment 1 of the present invention. The first embodiment of the vacuum cleaner 1 shown in Figure 1 is a stick-type cordless vacuum cleaner comprising a vacuum cleaner body 10, a suction nozzle 60, and an extension tube 90 that detachably connects the vacuum cleaner body 10 and the suction nozzle 60. This vacuum cleaner 1 can also be used as a handheld type by directly connecting the suction nozzle 60 to the vacuum cleaner body 10. Since this electric vacuum cleaner 1 has a distinctive feature in its main body 10, the following will describe the configuration of the main body 10, and the description of the suction port 60 and extension tube 90 will be omitted.

[0011] As shown in Figure 1, the vacuum cleaner body 10 comprises a suction device 20 and a dust collector 50 that is detachably attached to the suction device 20. Figure 2 is a partially perspective view of the vacuum cleaner body of the first embodiment, viewed from the right rear. Figure 3 is a left cross-sectional view of the vacuum cleaner body of the first embodiment. For convenience in explaining the configuration of the vacuum cleaner body 10, the directions as seen from a user holding the vacuum cleaner body 10 horizontally are indicated by arrows in Figures 2, 3, etc., as the front, back, left, right, up, and down directions of the vacuum cleaner body 10.

[0012] As shown in Figures 2 and 3, the suction device 20 comprises a housing 21, a cylindrical electric blower cover 30 provided inside the housing 21, an electric blower 40 housed inside the electric blower cover 30, and a battery 11 detachably attached to the housing 21. The housing 21 has an electrical component storage section 21a for housing electrical components such as the electric blower cover 30 housing the electric blower 40 and a circuit board 41 constituting the control unit, a handle section 21b connected to the rear end of the electrical component storage section 21a, and a suction cylinder section 21c connected via a connecting section 21x to the front end opposite the rear end of the electrical component storage section 21a.

[0013] As shown in Figures 2 and 3, the handle portion 21b has a roughly U-shaped form that is tilted to the side and has an upper end and a lower end when viewed from the left and right directions. The vacuum cleaner body 10 further includes an operating section 21d provided at the upper end of the handle portion 21b and a battery mounting section 21e provided at the lower end of the electrical component storage section 21a. The operating section 21d is provided with multiple operating switches, which can be used to switch from power OFF to standard mode operation or power mode operation, or to switch to power OFF while operating in standard mode or power mode. Multiple power receiving terminals (not shown) are provided at the front end of the battery mounting section 21e, and multiple power supply terminals (not shown) of the battery 11 mounted in the battery mounting section 21e are electrically connected to the multiple power receiving terminals.

[0014] Figure 4 is an enlarged cross-sectional view of the left side of the vacuum cleaner body of the first embodiment. Figure 5 is a cross-sectional view taken along line II in Figure 3. As shown in Figures 4 and 5, the electrical component storage section 21a has a front wall 21aa, a rear wall 21ab, left and right side walls 21ac, an upper wall 21ad, a bottom wall 21ae, a front end opening 21af provided in the front wall 21aa, and an exhaust port 21ag consisting of multiple small holes provided in the right side wall 21ac. As shown in Figures 3 and 4, the rear wall 21ab is inclined to protrude rearward from the upper end to the lower end. In other words, the rear wall 21ab is structured to protrude rearward as it goes downward, such that the distance to the lower part of the exhaust port 32a is longer than the distance to the upper part of the exhaust port 32a of the electric blower cover 30, which will be described later. As a result, the air discharged from the exhaust port 32a flows downward more easily.

[0015] Figure 6 is a cross-sectional view taken along line II-II in Figure 3. Figure 7 is a cross-sectional view taken along line III-III in Figure 3. Figure 8 is a cross-sectional view taken along line IV-IV in Figure 3. As shown in Figures 6, 7, and 8, in the electrical component housing section 21a, the bottom wall 21ae has a flat inner bottom surface, and the left and right side walls 21ac and the top wall 21ad have concave curved inner surfaces. Therefore, the lower internal space of the electrical component housing section 21a is wider than the upper internal space, and a substantially cylindrical electric blower cover 30 is housed in the upper internal space. More details about this electric blower cover 30 will be described later. The exhaust port 21ag is mostly located in the lower internal space (below the axis P of the electric blower 40) (see Figure 6).

[0016] As shown in Figures 2 and 6, the battery mounting portion 21e is a recess that opens to the rear and downward, located on the rear side of the lower surface of the bottom wall 21ae. The battery mounting portion 21e has left and right retaining pieces 21ea formed by the left and right side walls 21ac extending downward from the bottom wall 21ae. Furthermore, grooves 21eb extending in the front-rear direction are provided on the inner surfaces of the left and right retaining pieces 21ea. On the other hand, projections 11a extending in the front-rear direction are provided on the left and right sides of the battery 11. When the battery 11 is mounted from the rear of the battery mounting portion 21e, the left and right projections 11a slide while fitting into the left and right grooves 21eb.

[0017] As shown in Figures 2 and 3, the suction cylinder portion 21c of the housing 21 communicates with the electrical component storage portion 21a via the dust collector 50. The suction cylinder portion 21c has a front end opening 21ca and a connection port portion 21cb located behind the front end opening 21ca, and the front end opening 21ca and the connection port portion 21cb communicate with each other. A sealing member is provided at the connection port portion 21cb. In the housing 21, the portion of the housing 21 that runs from the lower side of the suction cylinder portion 21c along the front end side of the electrical component storage portion 21a is a dust collector mounting portion to which the dust collector 50 is detachably attached.

[0018] Now, let's describe the dust collector 50. As shown in Figures 2 and 3, the dust collector 50 comprises a dust collection container 51 and a filter unit 52. The dust collection container 51 has an opening at one end into which the filter unit 52 is detachably fitted, an openable and closable bottom lid 51a on the opposite side of the opening, and an air inlet 51b provided on the peripheral wall of the dust collection container 51. The filter unit 52 has a filter portion 52a that is fitted into one end opening of the dust collection container 51, and a mesh-like inner cylinder portion 52b provided on the filter portion 52a so as to be positioned inside the dust collection container 51, with the inner cylinder portion 52b and the filter portion 52a communicating with each other.

[0019] As shown in Figures 2 and 3, the dust collector 50 is mounted on the dust collector mounting section of the housing 21 with the dust collection container 51 facing forward and the filter unit 52 facing backward. At this time, the air inlet 51b of the dust collection container 51 is connected to the connection port 21cb of the suction cylinder 21c via a sealing member, and the locking claws 52aa provided on the outer circumferential surface of the filter portion 52a of the filter unit 52 engage with the locking portion 21acx provided on the right side wall 21ac of the housing 21. Furthermore, in the mounted state, the hook portion 51c provided on the outer circumferential surface of the peripheral wall of the dust collection container 51 engages with the locking recess 21cc provided at the lower end of the suction cylinder 21c, and the filter portion 52a is airtightly fitted into the fitting cylinder portion 31c of the electric blower cover 30, which will be described later (see Figure 4).

[0020] <Regarding the structure of the electric blower cover> Next, we will describe the electric blower cover 30. Figure 9 is a perspective view of the electric blower cover of the first embodiment, taken from the left rear. Figure 10 is a left cross-sectional view of the electric blower cover of the first embodiment, which houses the electric blower. As shown in Figures 9 and 10, the electric blower cover 30 has a main cylindrical portion 31a arranged around the electric blower 40 so as to support the outer frame of the electric blower 40 via a first vibration-damping member 34, an intake portion 31b provided upstream of the main cylindrical portion 31a in the direction A of the airflow generated when the electric blower 40 is driven, an exhaust portion 32a provided downstream of the main cylindrical portion 31a in the direction A of the airflow, and a tapered cylindrical portion 32b provided between the main cylindrical portion 31a and the exhaust portion 32a. The electric blower 40 is generally located inside the main cylindrical portion 31a, and when the electric blower 40 is driven, air flows from the intake portion 31b through the electric blower 40 towards the exhaust portion 32a. As shown in Figures 4 and 5, the exhaust port 21ag provided on the right side wall 21ac of the housing 21 is located on the intake port 31b side, forward of the exhaust port 32a of the electric blower cover 30.

[0021] To describe the electric blower cover 30 in more detail, as shown in Figures 9 and 10, in this embodiment, the electric blower cover 30 is composed of an upstream cover 31 which constitutes the intake port portion 31b and the main cylindrical portion 31a, and a separate downstream cover 32 which constitutes the tapered cylindrical portion 32b and the discharge port portion 32a.

[0022] As shown in Figure 10, the upstream cover 31 has an open end 31aa on the downstream side of the airflow direction A of the main cylindrical portion 31a, and this open end 31aa has an inner diameter larger than the outer diameter of the electric blower 40. The inner diameter of the upstream portion of the main cylindrical portion 31a gradually decreases compared to the outer diameter of the electric blower 40 as it moves upstream, and a grid-shaped intake port 31b is provided at the upstream end of the main cylindrical portion 31a so as to face the intake port 40a of the electric blower 40. The center of the intake port 31b is offset below the axis P of the electric blower 40.

[0023] Furthermore, as shown in Figures 4 and 10, the upstream cover 31 has a fitting cylinder portion 31c that fits airtightly with the front end opening 21af of the electrical component storage portion 21a of the housing 21 via a packing 33, so as to cover the periphery of the intake port portion 31b (see Figure 9). The packing 33 is provided on the outer circumferential surface of the fitting cylinder portion 31c. The fitting cylinder portion 31c is circular when viewed from the upstream side in the direction of airflow A, and the center of the fitting cylinder portion 31c is shifted downward from the center of the intake port portion 31b. Therefore, as shown in Figures 9 and 10, a guide wall portion 31ca is provided at the downstream end of the fitting cylinder portion 31c to guide air toward the intake port portion 31b without leakage. Furthermore, an upper projection 31ab is provided on the upper surface of the upstream side of the main cylindrical portion 31a, and a lower projection 31cb is provided at the lower end of the guide wall portion 31ca, and the upper projection 31ab and the lower projection 31cb are locked to the inner surface near the front end opening 21af of the housing 21 (see Figure 4).

[0024] Figure 11 is a cross-sectional view taken along the VV line in Figure 4. Figure 12 is a perspective view of the first vibration-damping member of the first embodiment. As shown in Figures 10 to 11, the first vibration-damping member 34 is a cylindrical rubber member and is fitted into the convex curved surface portion extending from the outer peripheral surface 40bf of the fan case 40b (outer frame of the electric blower 40), which has the largest outer diameter of the electric blower 40, to the vicinity of the suction port 40a. The first vibration-damping member 34 has a flange portion 34a positioned near the suction port 40a, and also has a plurality of cushion portions 34b positioned on the outer circumferential surface 40bf of the fan case 40b.

[0025] As shown in Figure 10, the flange portion 34a of the first vibration-damping member 34 abuts against the annular rib 31ac provided on the inside of the upstream end of the upstream cover 31, thereby ensuring a seal so that air between the fan case 40b and the main cylindrical portion 31a does not flow into the intake port 40a. The annular rib 31ac is a rib that protrudes downstream in the direction A of the airflow with respect to the axis P.

[0026] As shown in Figure 10, the multiple cushion portions 34b of the first vibration-damping member 34 are located downstream of the flange portion 34a in the direction A of the airflow. As shown in Figures 10 to 12, each cushion portion 34b is a portion that is bent in the thickness direction such that the outside is convex and the inside is concave, extends in the direction of the axis P, and is provided at equal intervals in the circumferential direction. The convex sides of the multiple cushion portions 34b abut against the inner circumferential surface 31af of the main cylindrical portion 31a of the upstream cover 31, and the mechanical vibrations of the electric blower 40 are absorbed by the cushion portions 34b and are less likely to be transmitted to the upstream cover 31. In other words, the mechanical vibrations of the electric blower 40 are absorbed by the elastic deformation of the multiple cushion portions 34b (elastic deformation in the direction in which the convex is crushed) and are less likely to be transmitted to the upstream cover 31.

[0027] As shown in Figures 9 and 10, in this embodiment, the downstream cover 32 of the electric blower cover 30 has a tapered cylindrical portion 32b and an outlet portion 32a, and also has an opposing open end 32c on the upstream side of the airflow direction A of the tapered cylindrical portion 32b. The tapered cylindrical portion 32b is formed in a substantially frustoconical shape, tapering towards the outlet portion 32a from the opposing open end 32c. The tapered cylindrical portion 32b may be a perfect frustoconical shape (linear taper), a parabolic taper, or an exponential taper. Furthermore, the tapered cylindrical portion 32b may include a tapered shape in which protrusions or depressions are provided on part of the inner and outer circumferential surfaces of the tapered cylindrical portion 32b, and a tapered shape that tapers in a stepped (bellows-like) manner from the opposing open end 32c towards the outlet portion 32a. Furthermore, the downstream cover 32 has a connecting cylinder portion 32d provided between the opposing open end portion 32c and the tapered cylindrical portion 32b, an exhaust cylinder portion 32e provided between the tapered cylindrical portion 32b and the exhaust port portion 32a, and a rectifying portion 32f provided within the range from the downstream end of the tapered cylindrical portion 32b in the direction A of the airflow to the exhaust port portion 32a to rectify the airflow. In Figure 10, the peripheral edge of the grid of the rectifying portion 32f that contacts the inner surface of the tapered cylindrical portion 32b appears to protrude from the inner surface of the tapered cylindrical portion 32b, creating a step, but as shown in Figures 6 and 9, there is actually no step. Therefore, the airflow along the inner surface of the tapered cylindrical portion 32b is not obstructed by a step.

[0028] As shown in Figures 9 and 10, in the downstream cover 32, the tapered cylindrical portion 32b has a roughly frustoconical shape in its longitudinal cross-section along the axis P, and the cross-sectional area of ​​the cross-section perpendicular to the axis P decreases from the upstream side to the downstream side in the direction of airflow A. Furthermore, in the downstream cover 32, the cross-sectional area of ​​the discharge port portion 32a is smaller than the cross-sectional area of ​​the main cylindrical portion 31a of the upstream cover 31, the cross-sectional area of ​​the connecting cylindrical portion 32d is equivalent to the cross-sectional area of ​​the opposing open end portion 32c, and the cross-sectional area of ​​the discharge cylindrical portion 32e is equivalent to the cross-sectional area of ​​the discharge port portion 32a.

[0029] Figure 13 is a perspective view of the downstream cover in the electric blower cover of the first embodiment. As shown in Figures 10 and 13, the tapered cylindrical portion 32b has a tapered inner circumferential surface that narrows toward the direction of airflow A2 (from upstream to downstream), and a plurality of mounting steps 32ba (in this case, three) are provided on this inner circumferential surface at equal intervals in the circumferential direction. In this embodiment, the inner circumferential surface is linearly tapered, but it may be a parabolic taper, an exponential taper, or a combination thereof. Each of the plurality of mounting steps 32ba has a flat surface 32bx facing the axis P direction and a surrounding rib 32by that surrounds the flat surface 32bx so as to be open toward the axis P direction and in directions perpendicular to the axis P. The plurality of mounting steps 32ba are concave scaffolds for fitting the downstream cover 32 to the downstream end of the electric blower 40 via the second vibration damping member 35.

[0030] Figure 14 is a perspective view of an electric blower according to the first embodiment. In this embodiment, the electric blower 40 has a fan case 40b positioned upstream of the airflow direction A1, and a motor unit 40c provided downstream of the fan case 40b to rotate a fan (not shown) inside the fan case 40b. Part of the motor unit 40c is located inside the fan case 40b. The outer diameter of the fan case 40b is larger than the outer diameter of the motor unit 40c. As shown in Figures 10 and 14, the fan case 40b has a suction port 40a provided at the upstream end and an exhaust port 40x provided at the downstream end. The exhaust port 40x opens towards the space between the motor unit 40c and the tapered cylindrical portion 31a, and the air inside the fan case 40b exits the exhaust port 40x and flows through the space around the motor unit 40c towards the exhaust port 32a. Here, the outer frame of the electric blower 40 refers to the part exposed to the outside of the electric blower 40, and includes the fan case 40b and the motor section 40c, and further includes mounting members for attaching vibration-damping members provided on the fan case 40b and the motor section 40c, respectively.

[0031] As shown in Figure 14, the electric blower 40 has a fan case 40b and a motor section 40c located downstream of the fan case 40b in the direction A of the airflow. Furthermore, a motor drive circuit board 40e is provided at the downstream end of the motor section 40c of the electric blower 40 via a plurality of (in this case, three) mounting legs 40d. In this case, the plurality of mounting legs 40d extend from near the rear end of the fan case 40b and form the outer frame of the electric blower 40. As shown in Figures 4 and 8, this circuit board 40e faces the direction A1 of the airflow, and the downstream surface 40ef of the circuit board 40e faces the outlet 32a. When the contour R of the outlet 32a is projected onto the downstream surface 40ef of the circuit board 40e, the contour R of the outlet 32a is contained within the downstream surface 40ef. The airflow from the electric blower 40 passes outside the circuit board 40e.

[0032] Multiple mounting legs 40d have a substantially U-shaped cross-section and are provided at equal intervals in the circumferential direction on the outer circumference of the downstream end of the motor section 40c, extending downstream of the motor section 40c and substantially parallel to the axis P. Multiple (in this case, three) notches 40ea are provided at equal intervals on the outer edge of the circuit board 40e, and multiple mounting legs 40d are fitted into multiple notches 40ea. Each downstream end of the multiple mounting legs 40d is positioned downstream of the circuit board 40e in the direction A of the airflow. Furthermore, a pair of lead wires 40f electrically connected to the motor section 40c extend downstream through holes formed in the circuit board 40e.

[0033] Figure 15A is a perspective view of the second vibration-damping member 35 of the first embodiment. Figure 15B is a perspective view of one half of the second vibration-damping member shown in Figure 15A. The second vibration-damping member 35 is made of rubber and, as shown in Figures 15A and 15B, has a recess 35a into which the downstream end of the mounting leg 40d (see Figure 14) is fitted, and a plurality (in this case, four) of cushion portions 35b around the recess 35a. The plurality of cushion portions 35b are formed by bulging multiple locations on the outer surface of the second vibration-damping member 35 to form multiple protrusions, and making the inner sides of the multiple protrusions holes or recesses.

[0034] As shown in Figures 9 and 13, a pair of mounting protrusions 32bb are provided on the outer circumferential surface of the tapered cylindrical portion 32b of the downstream cover 32, projecting in a direction perpendicular to the axis P, at positions with a central angle of 180° relative to each other. A third vibration-damping member 35x, having the same configuration as the second vibration-damping member 35 described in Figures 15A and 15B, is attached to the pair of mounting protrusions 32bb. Meanwhile, fitting ribs 21acy are provided on the inner surfaces of the left and right side walls 21ac of the electrical component housing portion 21a of the housing 21 to receive the pair of third vibration-damping members 35x so as to support the downstream cover 32 via the pair of third vibration-damping members 35x (see Figure 5).

[0035] On the outer circumferential surface of the connecting cylindrical portion 32d, multiple (in this case, three) receiving pieces 32da (see Figure 10) with a vertical L-shaped cross-section are provided at equal intervals in the circumferential direction, and multiple (in this case, three) locking protrusions 32db are provided between two adjacent receiving pieces 32da. Furthermore, as shown in Figure 13, a single notched lead wire opening 32ca is provided extending from the opposing open end 32c to the tapered cylindrical portion 32b, and a sealing vibration-damping member 36 (see Figure 10) is provided along the edge of the opposing open end 32c. However, at the position of the lead wire opening 32ca at the opposing open end 32c, a sealing portion 37c (see Figure 17), which is provided as part of the fourth vibration-damping member 37 described later, is positioned instead of the sealing vibration-damping member 36. The sealing vibration-damping member 36 is made of a material that combines vibration damping and sealing properties, and in this embodiment, it is made of a molded rubber product. The sealing vibration-damping member 36 may be a sealing tape, in which case multiple layers of sealing tape may be stacked thickly to achieve a thickness sufficient to provide both vibration damping and sealing properties.

[0036] On the other hand, as shown in Figures 9 and 10, the open end 31aa of the upstream cover 31 is slightly larger in diameter than the main cylindrical portion 31a, and receives the opposing open end 32c of the downstream cover 32 via the sealing vibration-damping member 36 and the sealing portion 37c. Furthermore, the outer circumferential surface of the open end 31aa of the upstream cover 31 is provided with a plurality of locking pieces 31ax that each lock with a plurality of locking projections 32db of the downstream cover 32. Each locking piece 31ax has a locking hole 31ay that is detachable from each locking projection 32db. When locking, each locking piece 31ax slides upward along the inclined surface of each locking projection 32db. When each locking piece 31ax is lifted, each locking hole 31ay detaches from each locking projection 32db.

[0037] Figure 16 is an explanatory diagram showing a fourth vibration-damping member 37 provided in the lead wire opening of the downstream cover of the first embodiment. Figure 17 is a perspective view of the fourth vibration-damping member 37 of Figure 16. As shown in Figures 16 and 17, the fourth vibration-damping member 37 consists of a rubber tip shaped to fit into the lead wire opening 32ca (see Figure 13) of the downstream cover 32, and has a notch for opening in a substantially V-shape or substantially U-shape. Furthermore, as shown in Figure 17, a plurality of pairs of recessed grooves 37a for inserting lead wires are formed at the position of the notch of the fourth vibration-damping member 37, and an outer peripheral groove 37b is formed along the outer peripheral surface. A pair of sealing portions 37c protrude from the outer peripheral grooves 37b at both ends of the third vibration-damping member 37.

[0038] The fourth vibration-damping member 37 shown in Figure 17 is installed by fitting its outer groove 37b onto the edge of the lead wire opening 32ca of the downstream cover 32 shown in Figure 13 (see Figure 16). A pair of lead wires 40f from the electric blower 40 shown in Figure 14 are passed through the notches (see Figures 16 and 17) of the fourth vibration-damping member 37 attached to the lead wire opening 32ca and are clamped and fixed at the positions of each pair of recessed grooves 37a. When the fourth vibration-damping member 37 is fitted into the lead wire opening 32ca, the gap in the notch is eliminated, and the holes formed by each pair of recessed grooves 37a are also closed by the pair of lead wires 40f.

[0039] As shown in Figure 10, the shape and structure of the flow straightening section 32f of the downstream cover 32 are not particularly limited, as long as they are shaped to provide a flow straightening effect to the airflow from the tapered cylindrical section 32b toward the outlet section 32a. In this embodiment, the flow straightening section 32f is formed in a grid shape having a predetermined thickness in the axial direction P (see Figure 6), and is provided at the boundary between the downstream end of the tapered cylindrical section 32b in the direction of airflow A and the outlet section 32e. This boundary is at the intermediate position Q in the axial direction P of the curved portion where the downstream end of the tapered cylindrical section 32b connects to the outlet section 32e. More specifically, in this embodiment, the downstream end of the tapered cylindrical section 32b includes a range of approximately 1 mm to 3 mm upstream from the intermediate position Q in the direction of airflow A, and the upstream end of the outlet section 32e includes a range of approximately 1 mm to 3 mm downstream from the intermediate position Q in the direction of airflow A. The rectifier section 32f has a thickness (for example, about 3 mm to 10 mm) in the axial direction P, and the middle of the rectifier section 32f in the thickness direction is positioned on the intermediate position Q. If a part of the rectifier section 32f is positioned on the intermediate position Q, the rectifier section 32f may be positioned at a shifted position on the upstream or downstream side. As shown in Figure 6, in this embodiment, the rectifier section 32f has a grid shape (approximately spiderweb shape) with multiple radial bars between multiple concentric circles, and the positions of the inner bars and outer bars are offset, but the bars may also be arranged radially (spiderweb shape). In this embodiment, the upstream end of the grid is a flat surface, but it may have a rounded shape such as a semicircle or a streamlined shape.

[0040] Referring to Figure 10, the procedure for housing the electric blower 40, to which the first vibration-damping member 34 and the second vibration-damping member 35 are attached, inside the electric blower cover 30 will be explained. First, the electric blower 40 is inserted into the opening end 31aa of the upstream cover 31 from the suction port 40a side. At this time, when the electric blower 40 is inserted until the first vibration-damping member 34 comes into contact with the stepped portion 31ag provided on the inner surface of the main cylindrical portion 31a of the upstream cover 31, the flange portion 34a of the first vibration-damping member 34 comes into contact with the annular rib 31ac inside the main cylindrical portion 31a.

[0041] Subsequently, the opposing open ends 32c of the downstream cover 32, to which the sealing vibration-damping member 36 and the fourth vibration-damping member 37 are attached, are fitted into the open end 31aa of the upstream cover 31. At this time, the pair of lead wires 40f of the electric blower 40 (see Figure 14) are passed through the notches of the fourth vibration-damping member 37 in advance (see Figure 16). When connecting the upstream cover 31 and the downstream cover 32, the downstream cover 32 is fitted onto the upstream cover 31 while aligning the multiple second vibration-damping members 35 attached to the multiple mounting legs 40d of the electric blower 40 so that they fit into the multiple mounting steps 32ba of the downstream cover 32. As a result, the electric blower 40 is supported within the electric blower cover 30 such that its axis P passes approximately through the center of the discharge pipe portion 32e and the discharge port portion 32a of the electric blower cover 30. By fitting the downstream cover 32 onto the upstream cover 31, the locking holes 31ay of the multiple locking pieces 31ax of the upstream cover 31 engage with the multiple locking protrusions 32db of the downstream cover 32 (see Figure 16), and the sealing portion 37c of the sealing vibration-damping member 36 and the fourth vibration-damping member 37 of the downstream cover 32 come into close contact with the stepped portion 31ak provided on the inner surface of the open end 31aa of the upstream cover 31 (see Figure 10).

[0042] As shown in Figures 4 and 5, when the electric blower cover 30 housing the electric blower 40 is supported within the housing 21, the inner surface of the rear wall 21ab of the housing 21 is an opposing wall surface 21abf facing the exhaust port 32a of the electric blower cover 30. This opposing wall surface 21abf is inclined backward from the upper end to the lower end. In other words, the opposing wall surface 21abf is not perpendicular to the axis P of the electric blower 40, but is inclined to guide the airflow downward. Furthermore, as shown in Figures 4 and 11, the electric blower cover 30 is positioned such that a space is formed between its outside and the inside of the housing 21. In this embodiment, the electric blower cover 30 is positioned within the housing 21 such that a first spatial region S1 and a second spatial region S2, which is wider than the first spatial region S1, are formed around it inside the housing 21.

[0043] As shown in Figures 4 and 8, when the space is divided into a first spatial region S1 and a second spatial region S2 by a virtual plane F passing through the central axis of the cylindrical electric blower cover 30 (a central axis that approximately coincides with the axis P), the electric blower cover 30 is positioned within the housing 21 such that a first spatial region S1 and a second spatial region S2 that is wider than the first spatial region S1 are formed. Furthermore, when the first spatial region S1 and the second spatial region S2 are divided by the plane F such that the volume of the second spatial region S2 is larger than the volume of the first spatial region S1, the exhaust port 21ag is positioned to open at least into the second spatial region S1. In this embodiment, as shown in Figures 4 and 8, the space above the plane F passing through the axis P of the electric blower 40 is the narrower first spatial region S1, and the space below the plane F is the wider second spatial region S2. In this embodiment, the exhaust port 21ag is also positioned to open into the first spatial region S1. When the first spatial region S1 and the second spatial region S2 are separated by the plane F in such a way that the difference between the volume of the first spatial region S1 and the volume of the second spatial region S2 is maximized, the opening area of ​​the exhaust port 21ag opening into the second spatial region S2 is larger than the opening area of ​​the exhaust port 21ag opening into the first spatial region S1.

[0044] <Explanation of the vacuum cleaner's operation> As shown in Figure 3, when the electric blower 40 is driven by operating the control unit 21d of the suction device 20, negative pressure is created inside the electric blower cover 30, causing air containing dust to flow into the front end opening 21ca of the suction cylinder 21c, and then the air containing dust flows into the dust collection container 51 of the dust collector 50 through the air inlet 51b of the dust collection container 51 from the connection port 21cb of the suction cylinder 21c. The air containing dust swirls inside the dust collection container 51, and relatively large first dust particles are centrifuged with the air inside the dust collection container 51, while smaller second dust particles pass through the mesh-like inner cylinder 52b and are captured by the filter 52a.

[0045] As shown in Figures 4 and 10, the air from which the second dust has been removed by passing through the filter section 52a flows from the fitting cylindrical section 31c of the electric blower cover 30 through the intake port 31b to the suction port 40a of the electric blower 40. The air that flows into the suction port 40a passes through the fan case 40b and through the flow path between the motor section 40c and the inner circumferential surface of the main cylindrical section 31a in the direction of arrow A1, passing through the tapered cylindrical section 32b, the rectifying section 32f and the discharge cylindrical section 32e to reach the discharge port 32a, from the discharge port 32a toward the rear wall 21ab of the housing 21, and is discharged to the outside from the discharge port 21ag on the right side wall 21ac (see Figure 2) of the housing 21. In this case, as shown in Figure 4, the airflow that travels straight from the electric blower 40 and is discharged into the housing 21 from the exhaust port 32a collides with the opposing wall surface 21abf, and then turns back toward the intake port 31b side as shown in airflow direction A4 and is exhausted to the outside from the exhaust port 21ag.

[0046] At this time, the inclined opposing wall surface 21abf guides most of the airflow discharged from the outlet 32a into a wide second spatial region S2. This configuration makes it possible to secure a long exhaust path to suppress noise even in a compact layout, and also allows the airflow to be guided into a wide second spatial region S2 inside the housing 21 to suppress pressure loss. In other words, the configuration in which the airflow collides with the opposing wall surface 21abf, folds back toward the intake port 40a side, and is exhausted to the outside from the exhaust port 21ag allows for a longer exhaust path and noise reduction without increasing the size of the housing 21, and also suppresses the increase in the number of parts, the increase in assembly man-hours, the increase in weight, and the increase in cost compared to Patent Document 1. Furthermore, by making the area around the electric blower 40 a double structure of the electric blower cover 30 and the housing 21, transmitted noise can be suppressed, and because the exhaust path is simple, there is no large pressure loss and the suction performance can be maintained.

[0047] Furthermore, as shown in Figures 4 and 8, when the first spatial region S1 and the second spatial region S2 are separated by a plane F passing through the axis P such that the volume of the second spatial region S2 is larger than the volume of the first spatial region S1, the exhaust port 21ag is positioned to open at least into the second spatial region S2. As a result, the airflow discharged from the exhaust port 32a of the electric blower cover 30 is more likely to pass through the wider second spatial region S2 than the narrower first spatial region S1 and head towards the exhaust port 21ag, thereby further reducing pressure loss. In this embodiment, when the first spatial region S1 and the second spatial region S2 are separated by the plane F such that the difference between the volume of the first spatial region S1 and the volume of the second spatial region S2 is maximized, the opening area of ​​the exhaust port 21ag opening into the second spatial region S2 is larger than the opening area of ​​the exhaust port 21ag opening into the first spatial region S2. Therefore, even when the exhaust port 21ag is positioned to open into the first spatial region S1, airflow is more likely to flow into the second spatial region S2, where the opening area of ​​the exhaust port 21ag is larger than that of the first spatial region S1. Furthermore, noise (especially high-frequency noise) from the motor section 40c of the electric blower 40 is attenuated by reflecting off the tapered inner surface of the tapered cylindrical section 32b, whose cross-sectional area decreases as it moves downstream in the direction of airflow A2 (suppression of electromagnetic noise). In this case, as shown in Figures 4 and 8, the circuit board 40e, which is provided at the downstream end of the electric blower 40 so as to face the exhaust port section 32a, has a size such that when the contour R of the exhaust port section 32a is projected onto the downstream surface 40ef of the circuit board 40e, the contour R of the exhaust port section 32a fits within the downstream surface 40ef. In other words, the circuit board 40e acts as an obstacle to prevent high-frequency noise from the motor section 40c from traveling directly towards the exhaust port section 32a. This configuration also contributes to suppressing electromagnetic noise.

[0048] (Second Embodiment) Figure 18 is a schematic left-side cross-sectional view of the electric blower cover of the second embodiment, which houses the electric blower. In Figure 18, elements similar to those in Figure 10 are denoted by the same reference numerals. As shown in Figure 18, the electric blower cover 130 of the second embodiment is provided with a second discharge port in the tapered cylindrical portion 32b of the downstream cover 32 of the electric blower cover 30 of the first embodiment. Note that in Figure 18, the fitting cylindrical portion 31c (see Figure 10) of the upstream cover 131 of the electric blower cover 130 is omitted from the illustration.

[0049] The second embodiment is described in detail as follows: A second outlet portion 32gba is provided in the tapered cylindrical portion 32gb of the downstream cover 32g. The opening area of ​​this second outlet portion 32gba is smaller than the opening area of ​​the outlet portion 32a. There may be one or more second outlet portions 32gba, and if there are more, the sum of the opening areas of the multiple second outlet portions 32gba is smaller than the opening area of ​​the outlet portion 32a. The shape of the second outlet portion 32gba is not particularly limited and may be, for example, circular, polygonal, elliptical, oblong or elliptical along the circumferential direction of the tapered cylindrical portion 32gb, oblong or elliptical along the longitudinal direction of the tapered cylindrical portion 32gb, etc. With this configuration, by discharging a portion of the airflow B passing through the tapered cylindrical section 32gb into the housing 21 from the second outlet section 32gba, the airflow velocity of the airflow A4 discharged into the housing 21 from the outlet section 32a is reduced, thereby reducing the noise (ventilation noise) caused by the airflow A4 moving from the outlet cylindrical section 32a to the exhaust port 21ag (see Figure 4).

[0050] (Third embodiment) Figure 19 is a schematic left-side cross-sectional view of an electric blower cover of a third embodiment, which houses an electric blower. In Figure 19, elements similar to those in Figure 10 are denoted by the same reference numerals. As shown in Figure 19, the electric blower cover 230 of the third embodiment is the electric blower cover 30 of the first embodiment with sound-absorbing material added. Note that in Figure 19, the fitting cylindrical portion 31c (see Figure 10) of the upstream cover 131 of the electric blower cover 230 is omitted from the illustration.

[0051] To describe the third embodiment in detail, a sheet-like internal sound-absorbing material 38 is attached to the inner surface (inner surface) of the tapered cylindrical portion 32b of the downstream cover 32 of the electric blower cover 230. Furthermore, a bottomed cylindrical external sound-absorbing material 39 is attached to the outer surface of the discharge pipe portion 32e so as to cover the discharge port portion 32a of the downstream cover 32. The bottom portion of the external sound-absorbing material 39 is in contact with the opposing wall surface 21ab. Both the internal sound-absorbing material 38 and the external sound-absorbing material 39 are made of porous sheet material, and the external sound-absorbing material 39 has a coarser texture than the internal sound-absorbing material 38 to the extent that air can circulate through it. With this configuration, the internal sound-absorbing material 38 attached to the inner surface of the tapered cylindrical portion 32b and the external sound-absorbing material 39 covering the discharge pipe portion 32a absorb noise (especially high-frequency noise), so noise can be suppressed more effectively than when the internal sound-absorbing material 38 and external sound-absorbing material 39 are not provided. Furthermore, either the internal sound-absorbing material 38 or the external sound-absorbing material 39 may be omitted. In addition, the external sound-absorbing material 39 may be attached to the opposing surface portion 21abf only at its bottom, or the bottom portion may be omitted.

[0052] (Fourth Embodiment) Figure 20 is a schematic left-side cross-sectional view of the electric blower cover of the fourth embodiment, which houses the electric blower. In Figure 20, elements similar to those in Figure 10 are denoted by the same reference numerals. As shown in Figure 20, the electric blower cover 330 of the fourth embodiment is configured in general the same way as the electric blower cover 230 of the third embodiment, except for a difference in its configuration. The following will mainly describe the differences between the fourth embodiment and the third embodiment. In the case of the electric blower cover 330 of the fourth embodiment, the connecting pipe portion 32d and the discharge pipe portion 32e (see Figure 19) of the downstream cover 332 are omitted, and the downstream end of the tapered pipe portion 32b in the direction A of the airflow becomes the discharge port portion 332a. Because the connecting pipe portion 32d is omitted, the upstream cover 331 extends slightly downstream. Furthermore, because the discharge pipe portion 32e of the downstream cover 332 is omitted, the rectifier portion 32f and the external sound-absorbing material 39 (see Figure 19) are also omitted. In the case of the fourth embodiment as well, when most of the airflow A4 discharged from the discharge port portion 332a collides with the opposing wall surface 21abf, it folds back towards the wide second spatial region S2 and is discharged to the outside from the exhaust port 21ag (see Figure 4).

[0053] (Fifth embodiment) Figure 21 is a schematic left-side cross-sectional view of the electric blower cover of the fifth embodiment, which houses the electric blower. In Figure 21, elements similar to those in Figures 10 and 20 are denoted by the same reference numerals. As shown in Figure 21, the electric blower cover 430 of the fifth embodiment is configured in general the same way as the housing 21 and electric blower cover 330 of the fourth embodiment, except that the configuration differs. The following will mainly describe the differences between the fifth embodiment and the fourth embodiment. In the fifth embodiment, the opposing wall surface 421abf of the rear wall 421ab of the housing 421 is approximately perpendicular to the axis P of the electric blower 40. Furthermore, a canopy portion 432ax for guiding airflow is provided on the upper half of the outlet portion 432a of the electric blower cover 430. In Figure 21, the canopy portion 432ax protrudes rearward from the outlet portion 432a so as to be continuous with the upper half of the tapered cylindrical portion 32b without any step, and the rear end of the canopy portion 432ax is close to the opposing wall surface 421abf. Alternatively, the canopy portion 432ax may be formed by cutting out a portion extending from the lower half of the outlet portion 432a to the lower half of the downstream end of the tapered cylindrical portion 32b.

[0054] With this electric blower cover 430, since a canopy portion 432ax is provided on the upper half of the outlet portion 432a, as shown in Figure 21, the airflow A3 that has passed through the tapered cylindrical portion 32b is easily discharged into the housing 421 from the lower half of the outlet portion 432a (below the axis P). Therefore, even if the rear wall 421ab of the housing 421 is roughly perpendicular to the axis P of the electric blower 40, most of the airflow A3 collides with the opposing wall surface 421abf from diagonally above and turns back towards the wide second spatial region S2 below, and the turned-back airflow A4 is discharged to the outside from the exhaust port 21ag (see Figure 4). In other words, the airflow toward the outlet portion 432a of the electric blower cover 430 is easily discharged into the housing 421 from the part of the outlet portion 432a where the canopy portion 432ax is not provided. In other words, the direction A3 of the airflow discharged from the outlet 432a by the canopy 432ax tends to be oblique to the opposing wall surface 421abf. As a result, the airflow that collides with the opposing wall surface 421abf at an oblique angle is more likely to be redirected towards the wider second spatial region S2, thereby further reducing pressure loss. The opposing wall surface 421abf may also be inclined as in the first to fourth embodiments (see Figures 4, 18 to 20).

[0055] (Sixth Embodiment) Figure 22 is a schematic left-side cross-sectional view of the electric blower cover of the sixth embodiment, which houses the electric blower. In Figure 22, elements similar to those in Figure 10 are denoted by the same reference numerals. As shown in Figure 22, the electric blower cover 530 of the sixth embodiment is configured in general the same way as the housing 21 and electric blower cover 30 of the first embodiment, except that the configuration differs. The following will mainly describe the differences between the sixth embodiment and the first embodiment. In the sixth embodiment, the opposing wall surface 421abf of the rear wall 421ab of the housing 421 is approximately perpendicular to the axis P of the electric blower 40. Furthermore, a canopy 532ax for airflow guidance is provided on the upper half of the discharge port 32a of the electric blower cover 530. In Figure 22, the canopy 532ax protrudes further rearward than the discharge port 32a so as to be continuous with the upper half of the discharge cylinder 32b without any step, and the rear end of the canopy 532ax is close to the opposing wall surface 421abf. Alternatively, the canopy 532ax may be formed by cutting out a portion extending from the lower half of the discharge port 32a to the lower half of the downstream end of the discharge cylinder 32b.

[0056] With this electric blower cover 530, since a canopy portion 532ax is provided on the lower half of the outlet portion 32a, as shown in Figure 22, the airflow A3 that has passed through the tapered cylindrical portion 32b and the rectifying portion 32f is easily discharged into the housing 421 from the lower half of the outlet portion 32a (below the axis P). Therefore, even if the rear wall 421ab of the housing 421 is approximately perpendicular to the axis P of the electric blower 40, most of the airflow A3 collides with the opposing wall surface 421abf from diagonally above and folds back towards the wide second spatial region S2 below, and the folded airflow A4 is discharged to the outside from the exhaust port 21ag (see Figure 4). The opposing wall surface 421abf may be inclined as in the first to fourth embodiments (see Figures 4, 18 to 20).

[0057] (Other embodiments) 1. In the above embodiment, a narrow first spatial region and a wide second spatial region are formed on the outside of the electric blower cover inside the housing, but the size of the space on the outside of the electric blower cover does not need to be locally varied. In other words, the distance (gap dimension) between the outer surface of the electric blower cover and the inner surface of the housing may be approximately uniform in all directions when the electric blower cover is viewed from the axial direction. 2. In the above-described embodiment (including modified examples), the electric blower cover is composed of two parts, an upstream cover and a downstream cover, but the electric blower cover may be composed of one part. 3. The electric blower cover of the above-described embodiment (including modified versions) is applicable not only to stick-type vacuum cleaners but also to canister-type or upright-type vacuum cleaners. [Explanation of Symbols]

[0058] 1: Electric vacuum cleaner, 10: Vacuum cleaner body, 20: Suction device, 21, 421: Housing, 21a: Electrical component storage section, 21aa: Front wall, 21ab, 421ab: Rear wall, 21abf, 421abf: Opposing wall surface, 21ac: Side wall, 21ad: Top wall, 21ae: Bottom wall, 21af: Front end opening, 21ag: Exhaust port, 21ca: Front end opening, 21cb: Connection port, 30, 130, 230, 330, 430, 530: Electric blower cover, 31, 131, 331: Upstream cover, 31a, 131a: Main cylinder section, 31aa, 131aa: Opening end, 31b, 131b: Intake port section, 32, 32 A: Direction of airflow, F: Plane, P: Axial center, S1: First spatial area, S2: Second spatial area

Claims

1. The system comprises a housing having an exhaust port, a cylindrical electric blower cover provided inside the housing, and an electric blower housed inside the electric blower cover. The electric blower cover has an intake port provided on the upstream side in the direction of the airflow generated by the electric blower, and an exhaust port provided downstream of the intake port in the direction of the airflow. The housing has a wall surface facing the outlet, The exhaust port is located on the intake port side of the discharge port, The airflow discharged into the housing from the exhaust port collides with the opposing wall surface, folds back toward the intake port, and is exhausted to the outside through the exhaust port. The exhaust port is formed on one side in a first direction perpendicular to the axis of the electric blower, The opposing wall surface is inclined such that it moves away from the discharge port as it moves toward one side in the first direction. Electric vacuum cleaner.

2. The electric blower cover is positioned such that a space is formed between its outer surface and the inside of the housing, and when the space is divided into a first spatial region and a second spatial region by a plane passing through the central axis of the cylindrical shape, a first spatial region and a second spatial region wider than the first spatial region are formed, as is the case when the space is positioned within the housing. The vacuum cleaner according to claim 1, wherein when the first spatial region and the second spatial region are separated by the plane such that the volume of the second spatial region is greater than the volume of the first spatial region, the exhaust port is positioned to open at least into the second spatial region.

3. The exhaust port is also positioned to open into the first spatial region, The vacuum cleaner according to claim 2, wherein when the first spatial region and the second spatial region are separated by the plane such that the difference between the volume of the first spatial region and the volume of the second spatial region is maximized, the opening area of ​​the exhaust port opening into the second spatial region is larger than the opening area of ​​the exhaust port opening into the first spatial region.

4. The vacuum cleaner according to claim 2, wherein the opposing wall surface is inclined so that the airflow discharged from the outlet is guided into the second spatial region.

5. The vacuum cleaner according to claim 2, wherein a canopy is provided over the discharge port so that the airflow discharged from the discharge port collides with the opposing wall surface at an oblique angle and heads toward the second spatial region.

6. The electric blower cover has a main cylindrical portion arranged around the electric blower to support the electric blower, The vacuum cleaner according to any one of claims 1 to 5, wherein the cross-sectional area of ​​the discharge port is smaller than the cross-sectional area of ​​the main cylinder.

7. The electric blower cover has a tapered cylindrical portion provided between the main cylindrical portion and the discharge port portion, The vacuum cleaner according to claim 6, wherein the cross-sectional area of ​​the tapered cylindrical portion decreases from the upstream side to the downstream side in the direction of the airflow.

8. The vacuum cleaner according to claim 7, wherein an internal sound-absorbing material is provided on the inner surface of the tapered cylindrical portion.

9. The vacuum cleaner according to claim 8, wherein an external sound-absorbing material that allows the airflow discharged from the outlet to pass through is provided around the outlet.

10. An external sound-absorbing material that allows the airflow discharged from the outlet to pass through is placed around the outlet. An electric vacuum cleaner according to any one of claims 1 to 5, provided as such.

11. The vacuum cleaner according to claim 7, wherein the tapered cylindrical portion has a second exhaust port having an opening area smaller than the opening area of ​​the discharge port.

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