vacuum cleaner

Abstract

To provide a vacuum cleaner capable of suppressing noise.SOLUTION: A vacuum cleaner includes: a cylindrical electric blower cover arranged inside a housing; and an electric blower stored inside the electric blower cover. The electric blower cover includes: a main cylinder part arranged in the periphery of the electric blower so as to support an outer frame of the electric blower via vibration-proof members; a suction port; a discharge port; and a tapered cylinder part arranged between the main cylinder part and the discharge port. A cross-sectional area of the discharge port is smaller than a cross-sectional area of the main cylinder part, and a cross-sectional area of the tapered cylinder part becomes smaller from an upstream side toward a downstream side in an air stream direction.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 a suction force by driving an electric blower provided in a casing, and sucks and removes dust on a cleaning surface. At this time, noise is generated from the electric blower. Patent Document 1 discloses an electric centrifugal blower aimed at improving the noise reduction effect. This electric centrifugal blower includes a motor, an impeller provided on the output shaft of the motor, a casing (including a cylindrical outer frame, circular frame-shaped first and second brackets) that houses the motor and the impeller so as to hold the motor, and a guide vane and a rectifying plate provided on the outer peripheral portion of the motor. The casing has a suction port provided on the upstream side in the direction of the airflow generated when the motor is driven, and a discharge port provided on the downstream side of the motor. In this electric centrifugal blower, the space between the casing and the impeller and the space between the casing and the motor serve as ventilation paths.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of the electric centrifugal blower described in Patent Document 1, the motor shaft is supported on the outer frame of the casing via first and second brackets and bearings. As a result, the motor's mechanical vibrations (especially bearing vibrations) are easily transmitted to the outer frame via the first and second brackets. Therefore, if this electric centrifugal blower is installed inside the casing of a vacuum cleaner, the outer frame will vibrate due to the motor's mechanical vibrations, and the noise caused by these vibrations will be emitted to the outside from the entire casing. Consequently, it is considered difficult to obtain sufficient noise reduction against the noise of the vacuum cleaner.

[0005] The present invention aims to provide an electric vacuum cleaner that takes these circumstances into consideration. [Means for solving the problem]

[0006] The present invention comprises a housing, a cylindrical electric blower cover provided inside the housing, and an electric blower housed inside the electric blower cover. The electric blower cover has a main cylindrical portion arranged around the electric blower so as to support the outer frame of the electric blower via a vibration-damping member, an intake portion provided upstream of the main cylindrical portion in the direction of the airflow generated when the electric blower is driven, an exhaust portion provided downstream of the main cylindrical portion in the direction of the airflow, and a tapered cylindrical portion provided between the main cylindrical portion and the exhaust portion. The present invention provides a vacuum cleaner in which the cross-sectional area of ​​the discharge port is smaller than the cross-sectional area of ​​the main cylindrical portion, and the cross-sectional area of ​​the tapered cylindrical portion decreases from the upstream side to the downstream side in the direction of the airflow. [Effects of the Invention]

[0007] The vacuum cleaner according to the present invention can reduce the noise of the electric blower generated inside the casing. [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] This is a perspective view of the first vibration-damping member of the first embodiment. [Figure 13] This is a perspective view of the downstream cover in the electric blower cover of the first embodiment. [Figure 14] This is a perspective view of the electric blower according to the first embodiment. [Figure 15A] This is a perspective view of the second vibration-damping member of the first embodiment. [Figure 15B] This is a perspective view of one half of the second vibration-damping member shown in Figure 15A, cut in half. [Figure 16] This is an explanatory diagram showing a fourth vibration-damping member provided in the lead wire opening of the downstream cover of the first embodiment. [Figure 17] Figure 16 is a perspective view of the fourth vibration-damping member. [Figure 18] This is a left-side cross-sectional view of the electric blower cover of Modification 1 of the first embodiment, which houses the electric blower. [Figure 19] This is a schematic left-side cross-sectional view of the electric blower cover of a modified example 2 of the first embodiment, which houses the electric blower. [Figure 20]It is a schematic left cross-sectional view of the electric blower cover of the second embodiment that houses the electric blower. [Figure 21] It is a schematic left cross-sectional view of the electric blower cover of the third embodiment that houses the electric blower. [Figure 22] It is a schematic left cross-sectional view of the electric blower cover of the fourth embodiment that houses the electric blower. [Figure 23] It is a schematic left cross-sectional view of the electric blower cover of the fifth embodiment that houses the electric blower.

Modes for Carrying Out the Invention

[0009] Hereinafter, this invention will be described in further 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 vacuum cleaner 1 of the first embodiment shown in FIG. 1 is a stick-type cordless vacuum cleaner including a cleaner main body 10, a suction port body 60, and an extension tube 90 that detachably connects the cleaner main body 10 and the suction port body 60. This vacuum cleaner 1 can also be used as a handy type by directly connecting the suction port body 60 to the cleaner main body 10. Since this vacuum cleaner 1 has features in the cleaner main body 10, the configuration of the cleaner main body 10 will be described below, and the description of the suction port body 60 and the extension tube 90 will be omitted.

[0011] As shown in FIG. 1, the cleaner main body 10 includes a suction device 20 and a dust collecting device 50 detachably attached to the suction device 20. FIG. 2 is a partial perspective view of the cleaner main body of the vacuum cleaner of the first embodiment as viewed from the upper right rear. FIG. 3 is a left cross-sectional view of the cleaner main body of the first embodiment. For the sake of convenience in explaining the configuration of the cleaner main body 10, the directions seen from a user holding the cleaner main body 10 horizontally are indicated by arrows in FIGS. 2, 3, etc. as the front, rear, left, right, upper, and lower directions of the cleaner main 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. Furthermore, the rear wall 21ab is structured to curve backward 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.

[0021] 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, with the outer diameter of the fan case 40b being larger than the outer diameter of the motor unit 40c. The fan case 40b has a suction port 40a provided at its upstream end and an exhaust port provided outside the motor unit 40c at its downstream end, and the air inside the fan case 40b flows out of the exhaust port, outside the motor unit 40c, and toward 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 does not include the shaft of the motor unit 40c or the bearings supporting this shaft. The outer frame of the electric blower 40 includes the fan case 40b and the motor case of the motor unit 40c, and further includes mounting members for attaching vibration-damping members provided on the fan case 40b and the motor case, respectively.

[0022] To explain 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 31b and the main cylindrical portion 31a, and a separate downstream cover 32 which constitutes the tapered cylindrical portion 32b and the discharge port 32a.

[0023] 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.

[0024] 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).

[0025] 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 34 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.

[0026] 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.

[0027] 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.

[0028] 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, but protrusions or depressions may be provided on a part of the inner and outer circumferential surfaces of the tapered cylindrical portion 32b. The tapered cylindrical portion 32b only needs to have a shape in which the outlet (outlet portion 32a side) is narrower than the inlet (opposing open end 32c side), and the inner circumferential surface of the tapered cylindrical portion 32b may be formed in a stepped shape, or it may have rounded irregularities on the inner circumferential surface. 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.

[0029] 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.

[0030] 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.

[0031] Figure 14 is a perspective view of an electric blower according to the first embodiment. As shown in Figure 14, the electric blower 40 has a fan case 40b and a motor section 40c provided on the downstream side 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 (motor case) 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, and 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] Multiple (in this case, three) L-shaped receiving pieces 32da (see Figure 10) are provided on the outer circumferential surface of the connecting cylindrical portion 32d at equal intervals in the circumferential direction, and multiple (in this case, three) locking protrusions 32db are provided between two adjacent receiving pieces 32da. The downstream cover 32 has a connecting cylindrical portion 32d between the opposing open end 32c and the tapered cylindrical portion 32b, having a cross-sectional area equivalent to that of the opposing open end 32c. Therefore, receiving pieces 32da that receive the open end 31aa while the sealing vibration-damping member 36 is sandwiched between the open end 31aa of the upstream cover 31 and the opposing open end 32c of the downstream cover 32 can be provided on the outer circumferential surface of the connecting cylindrical portion 32d. 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, instead of the sealing vibration-damping member 36, a sealing portion 37c (see Figure 17), which is provided as part of the fourth vibration-damping member 37 described later, is placed at the position of the lead wire opening 32ca at the opposing open end 32c. 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 also be a sealing tape, in which case multiple layers of sealing tape may be stacked thickly to obtain a thickness sufficient to obtain 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 be arranged radially. 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] <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.

[0043] 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 cylinder section 31c of the electric blower cover 30 through the intake port section 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 surface of the main cylinder section 31a in the direction of arrow A1, passing through the tapered cylinder section 32b, the rectifier section 32f and the discharge cylinder section 32e to reach the discharge port 32a, and is discharged from the discharge port 32a toward the rear wall 21ab of the housing 21. The air discharged from the discharge port 32a collides with the rear wall 21ab and folds back, and is discharged to the outside from the exhaust port 21ag on the right side wall 21ac (see Figure 2) of the housing 21. In this way, the exhaust path from the outlet 32a to the exhaust port 21ag can be made longer by folding it back, thus reducing the noise generated from the electric blower 40.

[0044] Generally, the noise from a vacuum cleaner body includes noise from the vibration of the electric blower (mechanical noise), wind noise from the air flowing inside the casing (ventilation noise), and high-frequency noise from the electric blower motor (electromagnetic noise). As shown in Figures 4 and 10, the noise generated by the operation of the electric blower 40 inside the electric blower cover 30 and released to the outside of the vacuum cleaner body 10 can be suppressed as follows.

[0045] As shown in Figures 4 and 10, with the electric blower cover 30 of this embodiment, vibrations of the electric blower 40 are absorbed and attenuated by the first vibration-damping member 34 and the multiple second vibration-damping members 35, thus suppressing rattling noise at the joint between the electric blower 40 and the electric blower cover 30 (suppression of mechanical noise). In other words, mechanical vibrations of the electric blower 40 are less likely to be transmitted to the electric blower cover 30. In addition, the vibration (resonance) of the pair of lead wires 40f (see Figure 16) is suppressed by the fourth vibration-damping member 37 provided in the lead wire opening 32ca (see Figure 13) of the downstream cover 32 of the electric blower cover 30 (suppression of mechanical noise). Furthermore, the electric blower cover 30 can be easily manufactured using multiple parts such as the upstream cover 31 and the downstream cover 32, and the resonance between the upstream cover 31 and the downstream cover 32 can be suppressed by the sealing vibration-damping member 36, thus contributing to the quietness of the vacuum cleaner 1. Furthermore, even if the air flowing inside the electric blower cover 30 is turbulent when it passes through the tapered cylindrical section 32b, it becomes rectified when it passes through the rectifying section 32f, and the rectification stabilizes as it passes through the discharge cylinder section 32e. Since the stable rectified air is discharged into the housing 21 from the discharge port section 32a, wind noise is suppressed to a low level (reduced ventilation noise).

[0046] In addition, the 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 A of the airflow (suppression of electromagnetic noise). Furthermore, as shown in Figures 4 and 8, the circuit board 40e is sized such that when the contour R of the outlet section 32a is projected onto the downstream surface 40ef of the circuit board 40e, the contour R of the outlet section 32a fits within the downstream surface 40ef. In other words, the circuit board 40e acts as an obstacle to prevent the high-frequency noise from the motor section 40c from traveling directly towards the outlet section 32a. This configuration also contributes to the suppression of electromagnetic noise.

[0047] These various noises can also be suppressed by covering the entire electric blower 40 with the electric blower cover 30. As described above, this embodiment makes it possible to reduce the noise level of the vacuum cleaner. Furthermore, as shown in Figure 10, with the electric blower cover 30 of this embodiment, the airflow from the electric blower 40 toward the exhaust port 32a flows along the axis P of the electric blower 40, so that exhaust pressure loss is kept small and the suction power is maintained.

[0048] (Modification 1 of the first embodiment) Figure 18 is a left-side cross-sectional view of the electric blower cover of Modification 1 of the first 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, in the case of the electric blower cover 130 of this modified example 1, by providing a shielding plate portion 131ba below the intake portion 131b of the upstream cover 131, the area of ​​the intake portion 131b is narrowed compared to the first embodiment, so that the entire intake portion 131b faces the suction port 40a of the electric blower 40. With this configuration, while maintaining the suction power, the high-frequency sound of the electric blower 40 is less likely to be emitted into the housing from the intake portion 131b, thereby enhancing the noise suppression effect.

[0049] (Modification 2 of the first embodiment) Figure 19 is a schematic left-side cross-sectional view of the electric blower cover of Modification 2 of the First Embodiment, which houses the electric blower. In Figure 19, elements similar to those in Figures 10 and 18 are denoted by the same reference numerals. As shown in Figure 19, the electric blower cover 230 of this modified example 2 is the electric blower cover 130 of modified example 1 with sound-absorbing material added. Note that in Figure 19, the fitting cylinder portion 31c (see Figure 18) of the upstream cover 131 of the electric blower cover 230 is omitted from the illustration.

[0050] To describe the modified example 2 in detail, a sheet-like first sound-absorbing material 38 is attached to the inner surface of the tapered cylindrical portion 32b of the downstream cover 32 of the electric blower cover 230. Furthermore, a bottomed cylindrical second 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. Both the first and second sound-absorbing materials 38 and 39 are made of porous sheet material, and the second sound-absorbing material 39 has a coarser texture than the first sound-absorbing material 38 to the extent that air can circulate through it. With this configuration, in addition to further attenuating high-frequency sound as it passes through the tapered cylindrical portion 32b, the attenuated high-frequency sound emitted from the discharge port portion 32a can be further attenuated by the second sound-absorbing material 39. Note that either the first or second sound-absorbing material 38 or 39 may be omitted. Furthermore, the first sound-absorbing material 38 or the second sound-absorbing material 39 may be applied to the electric blower cover 30 (see Figure 10) of the first embodiment.

[0051] (Second Embodiment) Figure 20 is a schematic left-side cross-sectional view of the electric blower cover of the second embodiment, which houses the electric blower. In Figure 20, elements similar to those in Figures 10 and 19 are denoted by the same reference numerals. As shown in Figure 20, the electric blower cover 330 of the second embodiment is configured in general the same way as the electric blower cover 230 of the first embodiment modification 2, except that the configuration differs. The following will mainly describe the differences between the second embodiment and the first embodiment modification 2. In the case of the electric blower cover 330 of the second embodiment, the connecting cylinder portion 32d (see Figure 19) is omitted from the downstream cover 332. Furthermore, the main cylinder portion 131a of the upstream cover 331 extends to the position of the tapered cylinder portion 32b of the downstream cover 332, and the open end portion 131aa provided at the downstream end of the main cylinder portion 131a in the direction A of the airflow and the opposing open end portion 332c provided at the upstream end of the tapered cylinder portion 32b are fitted together via a sealing member (not shown). Thus, the downstream cover 332 may be configured without the connecting cylinder portion. Note that in the electric blower cover 30 of the first embodiment (see Figure 10), the connecting cylinder portion 32d may also be omitted.

[0052] (Third embodiment) Figure 21 is a schematic left-side cross-sectional view of an electric blower cover of a third embodiment, which houses an 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 third embodiment is configured in general the same way as the electric blower cover 330 of the second embodiment, except for a difference in configuration. The following will mainly describe the differences between the third embodiment and the second embodiment. In the case of the electric blower cover 430 of the third embodiment, the discharge pipe portion 432e of the downstream cover 432 has an upstream constant diameter portion 432ea connected to the downstream end of the tapered cylindrical portion 32b in the direction A of the airflow, an enlarged diameter portion 432eb connected to the downstream end of the upstream constant diameter portion 432ea and expanding toward the downstream side, and a downstream constant diameter portion 432ec connecting the downstream end of the enlarged diameter portion 432eb to the discharge port portion 432a. In this case, when viewed from the discharge port portion 432a side, when the contour R of the discharge port portion 432a is projected onto the downstream surface 40ef of the circuit board 40e of the electric blower 40, the contour R is contained within the downstream surface 40ef. Thus, the discharge pipe portion 432e of the downstream cover 332 may become slightly thicker toward the downstream side. In the case of the electric blower cover 430 of the third embodiment, the inner diameter of the outlet portion 432a is larger than that of the upstream constant diameter portion 432ea, but when the contour R of the outlet portion 432a is projected onto the downstream surface 40ef of the circuit board 40e, the contour R of the outlet portion 432a is sized to fit within the downstream surface 40ef. The structure of the outlet pipe portion 432e of this embodiment may also be applied to the electric blower cover 30 of the first embodiment (see Figure 10).

[0053] (Fourth Embodiment) Figure 22 is a schematic left-side cross-sectional view of the electric blower cover of the fourth embodiment, which houses the electric blower. In Figure 22, elements similar to those in Figures 10 and 19 are denoted by the same reference numerals. As shown in Figure 22, the electric blower cover 530 of the fourth embodiment is configured in general the same way as the electric blower cover 230 of the first embodiment modification 2, except that its configuration differs. The following will mainly describe the differences between the fourth embodiment and the first embodiment modification 2. In the case of the electric blower cover 530 of the fourth embodiment, the flow straightening section 532f of the downstream cover 532 is fin-shaped. In this case, the flow straightening section 532f, consisting of a plurality of fins extending in the direction A of the airflow, is provided at approximately equal intervals on the inner circumferential surface of the discharge pipe section 32e. Thus, the configuration of the flow straightening section 532f can be changed. Note that the structure of the flow straightening section 532f consisting of fins of this embodiment may be applied to the electric blower cover 30432e of the first embodiment, or a combination of the lattice-shaped flow straightening section 32f on the upstream side and the flow straightening section 532f consisting of fins on the downstream side may be used.

[0054] (Fifth embodiment) Figure 23 is a schematic left-side cross-sectional view of the electric blower cover of the fifth embodiment, which houses the electric blower. In Figure 23, elements similar to those in Figures 10 and 20 are denoted by the same reference numerals. As shown in Figure 23, the electric blower cover 630 of the fifth embodiment is configured in general the same way as the electric blower cover 330 of the second embodiment, except for a difference in configuration. The following will mainly describe the differences between the fifth embodiment and the second embodiment. In the case of the electric blower cover 630 of the fifth embodiment, the discharge pipe portion 32e (see Figure 20) of the downstream cover 632 is omitted, and the downstream end of the tapered cylindrical portion 32b in the direction A of the airflow becomes the discharge port portion 632a. Although not shown in Figure 23, a grid-shaped flow straightening portion (see Figure 10) may be provided at the discharge port portion 632a. Thus, the downstream cover 332 may be configured without a discharge pipe portion. In addition, in the electric blower cover 30 of the first embodiment (see Figure 10), the discharge pipe portion 32e may also be omitted.

[0055] (Sixth Embodiment) In the first embodiment and its modifications 1 and 2, and in the second to fifth embodiments, the electric blower cover is made of resin, but at least one of the upstream cover and the downstream cover may be made of metal (e.g., aluminum) or the resin may be covered with metal (e.g., plated). With this configuration, a higher sound insulation effect can be obtained compared to when the electric blower cover is made of resin.

[0056] (Seventh Embodiment) In the first embodiment and its modifications 1 and 2, and the electric blower cover of the second to sixth embodiments, the upstream cover may have a lead wire opening for passing the lead wires of the electric blower and a vibration-damping member provided in the lead wire opening (see Figure 16). In this case, the lead wire opening is provided at the open end of the downstream end of the upstream cover.

[0057] (Other embodiments) 1. In the above-described embodiment (including modified examples), the electric blower cover is composed of two parts: an upstream cover and a downstream cover. However, the electric blower cover may be composed of one part. 2. 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.

[0058] Preferred embodiments of the present invention also include combinations of any of the embodiments described above. In addition to the embodiments described above, various modifications of this invention are possible. These modifications should not be considered outside the scope of this invention. This invention should include the meaning of equivalence to the claims and all variations within that scope. [Examples]

[0059] To investigate the noise level of the electric blower cover of the first embodiment (see Figure 10), an electric blower 40 was housed inside three types of electric blower covers (Samples 1-3) and an electric blower cover without a rectifier (Sample 4), all of which had the same configuration except that the position of the rectifier was different in the direction of the axis P. The noise level was measured when the electric blowers 40 of each of the Samples 1-4 were driven.

[0060] Sample 1: A grid-like flow straightening section 32f with a thickness of 5.5 mm in the axial direction P is provided at a position 8.5 mm upstream from the intermediate position Q between the tapered cylindrical section 32b and the discharge cylinder section 32e of the downstream cover 32, such that the center of the thickness of the flow straightening section 32f is positioned. Sample 2 (electric blower cover of the first embodiment): A grid-like flow straightening section 32f with a thickness of 5.5 mm in the axial direction P is provided at the intermediate position Q, such that the center of the thickness of the flow straightening section 32f is positioned there. Sample 3: A grid-like flow straightening section 32f with a thickness of 5.5 mm in the axial direction P is provided 13.75 mm downstream from the intermediate position Q, such that the center of the thickness of the flow straightening section 32f is positioned. The length in the axial direction P from the intermediate position Q to the opposing opening end 32c is 44 mm, and the length in the axial direction P from the intermediate position Q to the end of the discharge port 32a is 16.5 mm.

[0061] Vibration damping sheet (1000mm square, 60mm thick, approximately 21kg / m²) 3 A urethane foam sheet was laid on the floor, and samples 1 to 4 were placed sequentially on the vibration-damping sheet to measure noise levels. A first microphone, positioned on the floor to collect sound towards the exhaust port 32a of the electric blower cover 40, and a second microphone, suspended above the electric blower cover 40 to collect sound, were used. The distance from the first and second microphones to the electric blower 40 inside the electric blower cover 30 was approximately 1500 mm. Both the first and second microphones were Ono Sokki LA-4440 sound level meters. The airflow rate of the electric blower 40 was set to 0.409 m³. 3 The measurement was performed in a measurement environment with a room temperature of approximately 20°C and an ambient noise level of approximately 21 dB, with a setting of / min. The measurement results are shown in Table 1.

[0062] [Table 1]

[0063] Table 1 shows that the noise level was lower with a rectifier (Samples 1-3) than without a rectifier (Sample 4). Furthermore, among Samples 1-3, Sample 2 had the lowest noise level, followed by Samples 1 and 3 in that order. [Explanation of Symbols]

[0064] 1: Electric vacuum cleaner, 10: Vacuum cleaner body, 20: Suction device, 21: Housing, 21a: Electrical component storage section, 21aa: Front wall, 21ab: Rear wall, 21ac: Side wall, 21ad: Top wall, 21ae: Bottom wall, 21af: Front end opening, 21ag: Exhaust port, 21ca: Front end opening, 21cb: Connection port, 30,130,230,330,430,530,630: Electric blower cover, 31,131,331: Upstream cover, 31a,131a: Main cylinder section, 31aa,131aa: Opening end, 31b,131b: Intake port, 32,332,432,532,632: Downstream cover, 32a,432a: Discharge port, 32b: Tapered cylindrical section, 32c, 332c: Opposing open ends, 32ca: Lead wire opening, 32d: Connecting cylindrical section, 32e, 432e: Discharge cylindrical section, 32f, 532f: Rectifying section, 34: First vibration damping member, 35: Second vibration damping member, 35x: Third vibration damping member, 36: Sealing vibration damping member, 37: Fourth vibration damping member, 37c: Seal section, 38: First sound absorbing material, 39: Second sound absorbing material, 40: Electric blower, 40a: Suction port, 40b: Fan case, 40c: Motor section, 40d: Mounting leg, 40e: Circuit board, 40f: Lead wire, 41: Circuit board, 50: Dust collector, A: Airflow direction, P: Axis, Q: Intermediate position, R: Contour

Claims

1. The device comprises a housing, a cylindrical electric blower cover provided inside the housing, and an electric blower housed inside the electric blower cover. The electric blower cover has a main cylindrical portion arranged around the electric blower so as to support the outer frame of the electric blower via a vibration-damping member, an intake portion provided upstream of the main cylindrical portion in the direction of the airflow generated when the electric blower is driven, an exhaust portion provided downstream of the main cylindrical portion in the direction of the airflow, and a tapered cylindrical portion provided between the main cylindrical portion and the exhaust portion. The cross-sectional area of ​​the outlet portion is smaller than the cross-sectional area of ​​the main cylindrical portion, and the cross-sectional area of ​​the tapered cylindrical portion decreases from the upstream side to the downstream side in the direction of the airflow. The electric blower cover is formed along the direction of the axis of the electric blower and further has an exhaust pipe portion having the exhaust port portion, The electric blower cover is provided with the main cylindrical portion, the tapered cylindrical portion, and the discharge cylindrical portion in that order toward one side in the direction of the axis, and houses the electric blower such that one side in the direction of the axis is open to the electric blower. Electric vacuum cleaner.

2. The electric blower cover includes an upstream cover that constitutes the intake port and the main cylindrical portion, and a downstream cover that constitutes the tapered cylindrical portion and the exhaust port. The upstream cover has an open end on the downstream side of the main cylindrical portion in the direction of the airflow, The downstream cover has an opposing open end on the upstream side of the tapered cylindrical portion in the direction of the airflow that can be connected to the open end, The vacuum cleaner according to claim 1, wherein the open end and the opposing open end are connected via a sealing vibration-damping member.

3. The vacuum cleaner according to claim 2, wherein the downstream cover has a connecting cylindrical portion between the opposing open end and the tapered cylindrical portion, the connecting cylindrical portion having a cross-sectional area equal to that of the opposing open end.

4. The vacuum cleaner according to claim 2 or 3, wherein the downstream cover has the discharge pipe portion between the tapered cylindrical portion and the discharge port portion.

5. The vacuum cleaner according to claim 4, wherein the discharge pipe portion has a cross-sectional area equivalent to the cross-sectional area of ​​the discharge port portion.

6. The vacuum cleaner according to claim 4, wherein the downstream cover has a flow straightening section that straightens the airflow in the range from the downstream end of the tapered cylindrical section in the direction of the airflow to the discharge port.

7. The vacuum cleaner according to claim 6, wherein the flow straightening section is provided at a position including the boundary between the tapered cylindrical section and the discharge cylinder section in the range from the downstream end of the tapered cylindrical section to the upstream end of the discharge cylinder section in the direction of the airflow.

8. The vacuum cleaner according to claim 6, wherein the rectifier section is formed in a grid or fin shape.

9. The vacuum cleaner according to claim 2 or 3, wherein the downstream cover has sound-absorbing material on the inner surface of the tapered cylindrical portion.

10. The vacuum cleaner according to claim 2 or 3, wherein at least one of the upstream cover and the downstream cover is made of metal or is covered with metal.

11. The vacuum cleaner according to claim 2 or 3, wherein the upstream cover or the downstream cover has a lead wire opening for passing the lead wires of the electric blower, and a vibration-damping member provided in the lead wire opening.

12. The electric blower further comprises a substrate provided at the downstream end in the direction of the airflow, The substrate faces the direction of the airflow, and the downstream surface of the substrate faces the outlet portion. The vacuum cleaner according to any one of claims 1 to 3, wherein when the contour of the discharge port is projected onto the downstream surface of the substrate, the contour fits within the downstream surface.

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