Blowing structure and electric cleaner including the same

Abstract

The air supply structure includes: a first air passage having a communication portion provided on a peripheral wall thereof and through which air sucked from the air suction port flows; and a second air passage through which air flowing in from the communication portion flows to the exhaust port, the communication portion having at least one communication hole penetrating the peripheral wall and communicating the first air passage and the second air passage, the communication hole being inclined with respect to the thickness direction of the peripheral wall.

Description

Technical Field

[0001] This disclosure relates to an air delivery structure and an electric vacuum cleaner equipped with such an air delivery structure. This application claims priority based on Japanese Patent Application No. 2023-185661, filed on October 30, 2023, the contents of which are incorporated herein by reference. Background Technology

[0002] In recent years, biomimetics, a technology that mimics the diverse functions of living organisms, has garnered attention. Furthermore, Natural Technology (registered trademark) is well-known as an example of applying such biomimetics to the manufacture of electrical products and other similar products.

[0003] Patent Document 1 discloses a handheld vacuum cleaner comprising: a main body housing housing an electric fan (motor and fan); a dust collection box having a suction nozzle detachably mounted to the front end of the main body housing; a filter device disposed at the front end of the main body housing and housed within the dust collection box; and a handle portion disposed at the rear end of the main body housing. In this vacuum cleaner, the interior of the handle portion forms part of a ventilation path, a second opening is provided downstream of the airflow direction of the handle portion, and a third opening is provided upstream of the airflow direction of the handle portion. When the electric fan is driven for cleaning, dust-laden air flows from the suction path of the suction nozzle into the dust collection box by suction force, the dust is captured by the filter device, and the air passing through the filter device and the electric fan flows into the handle portion through the main body housing, and is discharged to the outside through the third opening and the second opening.

[0004] In this cleaner, air is forced through the handle section and exhausted from the exhaust ports (second and third openings) located on the handle section, thereby extending the ventilation path from the electric fan to the exhaust ports. As a result, the driving noise of the electric fan, or noise including airflow noise, is attenuated by the extended ventilation path, thus achieving quiet operation.

[0005] Existing technical documents Patent documents Patent Document 1: WO2020 / 189226 Summary of the Invention The problem the invention aims to solve In the cleaner described in Patent Document 1, a portion of the air passing through the handle flows towards the rear end of the main body and then folds back towards the front end to be discharged to the outside through the second opening, thereby making the cleaner compact in the front-to-back direction. However, this makes it difficult to lengthen the ventilation path from the electric fan to the second opening to a sufficient length to attenuate noise over distance and achieve quiet operation. This reduction in noise accompanying ventilation is not limited to electric vacuum cleaners; it is a problem inherent in devices with ventilation structures, such as electric blowers that spray air and sprayers that atomize air mixed with liquid.

[0006] This disclosure was made in consideration of the above-mentioned problems, and its purpose is to provide an air supply structure capable of reducing noise contained in circulating air, and an electric vacuum cleaner having such an air supply structure. Furthermore, one aspect of this disclosure includes a technical concept based on the structure of shark gills, which is related to bionics.

[0007] Solution for solving the problem This disclosure provides an air supply structure, including: a first ventilation path having a connecting portion on its peripheral wall, through which air drawn in from an air intake flows; and a second ventilation path allowing air flowing in from the connecting portion to flow to an exhaust port, the connecting portion having at least one connecting hole penetrating the peripheral wall and connecting the first ventilation path and the second ventilation path, the connecting hole being inclined relative to the thickness direction of the peripheral wall.

[0008] This disclosure provides an electric vacuum cleaner comprising: an air intake section having an air intake port; an exhaust section having an exhaust port; an air supply section for drawing in air from the air intake port and delivering it to the exhaust section and discharging it from the exhaust port; and a dust removal section for removing dust from the air drawn in by the air intake section, wherein the exhaust section has the air supply structure.

[0009] Invention Effects According to the air supply structure disclosed herein, it is possible to reduce the ventilation noise of airflow within the ventilation path. Attached Figure Description

[0010] Figure 1 This is a perspective view showing a first embodiment of an electric vacuum cleaner having the air delivery structure according to the present invention.

[0011] Figure 2 This is a longitudinal sectional view showing the suction inlet body of the electric vacuum cleaner according to the first embodiment.

[0012] Figure 3 This is a perspective view showing the main body of the vacuum cleaner in the electric vacuum cleaner according to the first embodiment.

[0013] Figure 4 It means to remove.Figure 3 A 3D view of the front of the main body of the vacuum cleaner.

[0014] Figure 5 This is a longitudinal sectional view showing the main body of the vacuum cleaner according to the first embodiment.

[0015] Figure 6 This is a longitudinal sectional view showing the first noise reduction section and the second noise reduction section of the vacuum cleaner body according to the first embodiment.

[0016] Figure 7 This is a longitudinal sectional view showing the third noise reduction section of the vacuum cleaner body according to the first embodiment.

[0017] Figure 8 This is a perspective view of the cylindrical tube of the cylindrical component of the first embodiment, viewed from the oblique front side.

[0018] Figure 9 This is a perspective view of the cylindrical tube of the cylindrical component in the first embodiment, viewed from the oblique rear side.

[0019] Figure 10 This is a view of the cylindrical component of the first embodiment from the front side.

[0020] Figure 11 Viewed from the left side Figure 10 A diagram of the cylindrical component.

[0021] Figure 12 Viewed from the rear side Figure 10 A diagram of the cylindrical component.

[0022] Figure 13 Viewed from one end side Figure 10 A diagram of the cylindrical component.

[0023] Figure 14 Viewed from the other end Figure 10 A diagram of the cylindrical component.

[0024] Figure 15 yes Figure 10 A cross-sectional view along line aa.

[0025] Figure 16 yes Figure 10 BB-oriented sectional view.

[0026] Figure 17 yes Figure 10 The cc-line view section.

[0027] Figure 18 yes Figure 15 A magnified view of a portion of the image.

[0028] Figure 19 yes Figure 8 A magnified view of a portion of the image.

[0029] Figure 20 This is an explanatory diagram showing the air supply structure of the fifth embodiment.

[0030] Figure 21 This is an explanatory diagram showing the air supply structure of the sixth embodiment. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings. Furthermore, the following description is illustrative in all respects and should not be construed as limiting the scope of the invention.

[0032] (First Implementation) In a first embodiment, an electric vacuum cleaner is provided, comprising: an air intake section having an air intake port; an exhaust section having an exhaust port; an air supply section for drawing in air from the air intake port and supplying it to the exhaust section and discharging it from the exhaust port; and a dust removal section for removing dust from the air drawn in by the air intake section. The exhaust section is provided with an air supply structure capable of reducing ventilation noise in the ventilation path connecting the air intake port and the exhaust port.

[0033] Figure 1 This is a perspective view showing a first embodiment of an electric vacuum cleaner 1 having the air delivery structure of this disclosure. Figure 1 The text indicates the user's forward, backward, left, right, up, and down directions when using the electric vacuum cleaner 1. The structure of the electric vacuum cleaner 1 is based on... Figure 1 The description is based on the directions shown: front, back, left, right, up, and down. This electric vacuum cleaner 1 is a stick-type electric vacuum cleaner, comprising a vacuum cleaner body 2 and an intake body 3 that is detachably connected to the suction section of the vacuum cleaner body 2. The vacuum cleaner body 2 includes an exhaust section, an air supply section, and a dust removal section. Figure 1 The diagram shows the state of the electric vacuum cleaner 1 cleaning the floor F. At this time, the user has a handle 6 located at the upper end 5b of the housing 4 of the vacuum cleaner body 2. The electric vacuum cleaner 1 is positioned with the suction inlet 3 at the front, the handle 6 at the rear, and the vacuum cleaner body 2 tilted backward from the lower end 5a towards the upper end 5b. In the following description, [the following will be used as a reference]. Figure 1 The lower end 5a of the vacuum cleaner body 2 shown is called one end 5a, and the upper end 5b is called the other end 5b.

[0034] In this embodiment, the housing 4 is cylindrical in shape, but not limited to a cylindrical shape; it can be partially or entirely square-shaped, or it can be a cylindrical shape with a polygonal cross-section. In this embodiment, the handle 6 is ring-shaped, more specifically, it is oblong when viewed from the left-right direction and rod-shaped when viewed from the front-back direction. An operating part 8 (not shown) is provided on the front 7 of the portion surrounding the oblong hole of the handle 6. The operating part 8 has multiple push-button switches, allowing the user to operate the electric suction machine 42 (see reference 42) by pressing the switches on the handle 6. Figure 5The output can be adjusted (switching between running and stopping, switching between weak and strong modes, etc.). Since the handle 6 is ring-shaped (oblong), the user can smoothly move their hand to a position where the handle 6 is easy to grip, depending on the tilt angle of the electric vacuum cleaner 1 relative to the floor surface F.

[0035] Figure 2 This is a perspective view showing the suction inlet body 3 of the electric vacuum cleaner 1 according to the first embodiment. The suction inlet body 3 has: a suction inlet main body 21 placed on the ground F; a joint portion 22 connected to the suction inlet main body 21; and a connecting pipe portion 23 connected to the joint portion 22. An air intake 25 is provided at the bottom of the suction inlet main body 21, and a connecting port 26 is provided at the end of the connecting pipe portion 23. A ventilation passage 27 is provided inside the suction inlet body 3 to communicate between the air intake 25 and the connecting port 26. By connecting the connecting pipe portion 23 to the suction inlet main body 21 via the joint portion 22, the connecting pipe portion 23 can be rotated relative to the suction inlet main body 21 in the forward and backward direction and the left and right direction.

[0036] Figure 3 This is a perspective view showing the vacuum cleaner body 2 of the electric vacuum cleaner according to the first embodiment. The housing 4 of the vacuum cleaner body 2 has an air intake 31 on one end 5a side of its end face. Figure 3 The image shows the vacuum cleaner body 2 with the suction port 3 detached from the suction port 31. The connecting tube 23 of the suction port 3 (see reference...) Figure 2 The suction port 31 of the vacuum cleaner body 2 can be detachably inserted. The electric vacuum cleaner of this embodiment may also include other accessories besides the suction port 3. Examples of other accessories include gap nozzles, brush nozzles, and hose nozzles. Therefore, the suction port 31 of the vacuum cleaner body 2 can be detachably fitted with other accessories besides the suction port 3. For example, when cleaning corners and gaps between furniture by connecting the gap nozzle to the vacuum cleaner body 2, if the user holds the handle 6 with one hand and supports the back of the housing 4 with the other, it is easy to move the gap nozzle to the target position. Furthermore, in the electric vacuum cleaner 1 of this embodiment, the battery mounting part 10, in which the battery 9 is detachably installed, is located at the rear of one end 5a of the housing 4. Therefore, the center of gravity is lowered due to the battery 9 being located near the suction port 31, thus making the operation of the vacuum cleaner body 2 easier.

[0037] Figure 4 It means to remove. Figure 3 A three-dimensional view of the front part of the housing 4 of the main body 2 of the vacuum cleaner. Figure 5 This is a longitudinal sectional view showing the vacuum cleaner body 2 according to the first embodiment. Figure 4 and Figure 5In the attached drawing, reference numeral 49 indicates the central axis of the housing 4. The housing 4 has a plurality of small-hole-shaped discharge ports 32 on its peripheral surface at the other end 5b. In this embodiment, when cleaning is performed using the electric vacuum cleaner 1, the plurality of discharge ports 32 are arranged at the rear of the housing 4. Furthermore, the plurality of discharge ports 32 can be provided on at least one of the left and right sides of the other end 5b of the housing 4, or on at least one of the left and right sides and the rear. Furthermore, the size of the plurality of discharge ports 32 can be uniform, or it can have different sizes in three stages: large, medium, and small. When the sizes of the plurality of discharge ports 32 are different, a group of small-sized (e.g., diameter 0.5~1.0 mm), medium-sized (e.g., diameter 1.0~1.5 mm), and large-sized (e.g., diameter 1.5~2.0 mm) discharge ports 32 can be arranged sequentially from the side closest to the other end 5a. Additionally, the discharge ports 32 are not arranged in the portion overlapping with the electric suction unit 42. As a result, the exhaust port 32, which is opposite to and close to the electric suction hood 47 covering the electric suction 42, disappears, thus reducing the noise leakage to the outside compared to the case where the exhaust port 32 is opposite to and close to the electric suction hood 47.

[0038] Inside the housing 4 are arranged: a ventilation passage 41 that directs air from the intake port 31 to the exhaust port 32; an electric air intake motor 42 disposed in the ventilation passage 41 as an air supply unit; a dust collection unit 43 disposed in the ventilation passage 41 upstream of the electric air intake motor 42 in the airflow direction as a dust removal unit; a first noise reduction unit 44 disposed in the ventilation passage 41 between the intake port 31 and the dust collection unit 43; a second noise reduction unit 45 disposed in the ventilation passage 41 between the dust collection unit 43 and the electric air intake motor 42; and a third noise reduction unit 46 disposed in the ventilation passage 41 between the electric air intake motor 42 and the exhaust port 32. Furthermore, the electric air intake motor 42 is surrounded by an electric air intake motor cover 47. An exhaust unit is located between the electric air intake motor 42 and the exhaust port 32 within the ventilation passage 41.

[0039] The first noise reduction unit 44 is disposed within the housing 4, forming a portion of the ventilation path 41 located upstream of the dust collection unit 43 in the airflow direction. The second noise reduction unit 45 is disposed within the housing 4, forming a portion of the ventilation path 41 between the dust collection unit 43 and the electric suction unit 42. The third noise reduction unit 46 is disposed within the housing 4, forming a portion of the ventilation path 41 located downstream of the electric suction unit 42 in the airflow direction.

[0040] Figure 6 This is a longitudinal sectional view showing the first and second noise-reducing parts of the vacuum cleaner body according to the first embodiment. The first noise-reducing part 44 includes a noise-reducing tube 71 and a noise-reducing cover 72 that covers the outer periphery of the noise-reducing tube 71. Furthermore, in Figure 6In this embodiment, the noise-reducing cover 72 covers a portion of the outer periphery of the noise-reducing tube 71, but may also cover the entire outer periphery of the noise-reducing tube 71. The noise-reducing tube 71 has an opening 71a connected to the air intake 31 and an opening 71b connected to an inlet 43a on one end side of the dust collection section 43. At least a portion of the noise-reducing tube 71 has a structure that allows air to pass through. In this embodiment, the structure that allows air to pass through the noise-reducing tube 71 is a plurality of through holes 71c penetrating the inner and outer surfaces of the noise-reducing tube 71. Alternatively, the structure that allows air to pass through the noise-reducing tube 71 may be a sound-absorbing material made of a breathable material (e.g., polyurethane foam) covering the inner surface of the noise-reducing tube 71. In this case, the noise-reducing tube 71 may not have a plurality of through holes 71c, and may not have a noise-reducing cover 72.

[0041] The space between the noise-reducing tube 71 and the noise-reducing cover 72 is called the expansion chamber 71d. The first noise-reducing part 44 is configured to reduce noise including ventilation sound (airflow sound) of air flowing from the air intake 31 to the first noise-reducing part 44. The noise from the air intake 31 is transmitted to the interior of the noise-reducing tube 71 of the first noise-reducing part 44. This noise (sound wave) is introduced into the expansion chamber 71d through multiple through holes 71c of the noise-reducing tube 71 and is partially reduced by sound wave interference within the expansion chamber 71d. As a result, the noise level leaking to the outside of the housing 4 is reduced. Since the first noise-reducing part 44 is provided on the ventilation path 41 near the air intake 31 of the vacuum cleaner body 2, noise reduction effect can be obtained even if accessories (suction inlet body, gap nozzle, brush nozzle, hose nozzle, etc.) without noise reduction parts are installed on the vacuum cleaner body 2.

[0042] return Figure 2 In this embodiment, a noise reduction section 24 on the intake body 21 of the intake body 3 is provided, thus achieving a noise reduction effect within the intake body 3. The intake body 21 includes a lower housing 21a, an upper housing 21b, an upper cover 21c, a rotating brush 21d, and a drive motor (not shown) for rotating the rotating brush 21d. The noise reduction section 24 on the intake body side has multiple through holes 24a in the upper housing 21b located above the rotating brush 21d, and an expansion chamber 24b serving as the space between the upper housing 21b and the upper cover 21c. The multiple through holes 24a communicate with the expansion chamber 24b. In this intake body 3, noise (sound waves), including the rotational sound of the rotating brush 21d and the ventilation sound of airflow through the suction port 25, is introduced into the expansion chamber 24b through the multiple through holes 24a, resulting in partial noise reduction due to sound wave interference within the expansion chamber 24b. Consequently, the noise level leaking to the outside of the intake body 3 is reduced.

[0043] return Figure 6The dust collection section 43 has an inlet 43a at one end for air containing dust to flow in from the intake port 31, and an outlet 43b at the other end for discharging the dust-free air to the second noise reduction section 45. A dust collection bag or dust collection device is housed within the internal space of the dust collection section 43. In the case of a dust collection bag, a paper bag, which stores dust within a breathable bag body, is used. In the case of a dust collection device, if it is a dust collection device comprising a container body and a filter, a structure is considered in which dust captured by the filter is stored within the container body, and the dust-free air is discharged from the exhaust port of the dust collection device. Alternatively, in the case of a cyclone-type dust collection device, a structure can be considered as follows: a cyclone section including a centrifugal separation section (inner cylinder section) and a container body is used to separate dust, the separated dust is stored within the container body, and the dust-free air is discharged from the exhaust port of the cyclone section.

[0044] A closable cover (not shown) forming part of the housing 4 is provided near the dust collection section 43. The cover can be opened to remove the dust bag or dust collection device (dust container) from the dust collection section 43 to dispose of the dust. The cover is a double-layered structure in which a part of the outer wall (housing 4) is integrated with a part of the wall forming the dust collection section 43. The cover can be opened to remove the dust bag, etc. The double-layered cover also reduces operating noise. Furthermore, to more effectively reduce wind noise (inhalation), a filter-type dust collection device and dust collector are preferred over a cyclone-type dust collection device. In a cyclone-type dust collection device, the wind noise increases because the wind speed increases in the cyclone separator section. With a filter-type dust collection device and dust bag, since it does not have a cyclone dust removal section, wind noise (inhalation noise) can be reduced compared to a cyclone dust removal device.

[0045] The second noise reduction unit 45 includes a noise reduction tube 73 and a noise reduction cover 74. The noise reduction tube 73 has an opening 73a at one end connected to the outlet 43b of the dust collection unit 43 and an opening 73b at the other end connected to the intake port 42a of the electric air intake motor 42. The noise reduction cover 74 only needs to cover at least a portion of the outer periphery of the noise reduction tube 73; in this embodiment, it covers the entire outer periphery of the noise reduction tube 73. The noise reduction tube 73 has a straight tube portion 75 and a tapered portion 76 that extends upward toward the airflow direction (one end side). The tapered portion 76 is provided on the upstream side (one end side) of the airflow direction of the noise reduction tube 73. The opening 73a at the largest end of the tapered portion 76 is connected to the other end forming the peripheral wall of the dust collection unit 43, and the smallest opening at the other end of the tapered portion 76 is connected to one end of the straight tube portion 91. One end of the noise reduction cover 74 is connected to the outside near the opening 73a at one end of the cone 76, and the other end of the noise reduction cover 74 is connected to one end of the electric suction cover 47 that covers the electric suction machine 42.

[0046] The straight section 75 of the noise-reducing tube 73 has a ventilable structure on at least a portion of its surrounding surface. In this embodiment, the ventilable structure of the straight section 75 is a plurality of through holes 75a penetrating the inner and outer surfaces of the straight section 75. Alternatively, the ventilable structure of the straight section 75 may be a sound-absorbing material made of a ventilable material (e.g., polyurethane foam) covering the inner surface of the straight section 75. In this case, the straight section 75 may not have a plurality of through holes 75a, and may not have a noise-reducing cover 74.

[0047] The space between the noise-reducing tube 73 and the noise-reducing cover 74 forms the expansion chamber 77. The second noise-reducing section 45 is configured to reduce noise including ventilation noise from the air flowing from the dust collection section 43 to the second noise-reducing section 45 and the driving noise (high-frequency sound) of the electric suction motor 42 transmitted from the electric suction motor 42 to the second noise-reducing section 45. The noise (sound waves) transmitted to the inside of the noise-reducing tube 73 to the second noise-reducing section 45 is introduced into the expansion chamber 77 through multiple through holes 75a of the straight tube section 91, and is partially reduced due to sound wave interference within the expansion chamber 77. As a result, the noise level leaking to the outside of the housing 4 is reduced. In addition, a pair of spacers 78 are provided between the outer surface (front and rear sides) in the direction of the central axis 49 of the noise-reducing cover 74 and the inner surface (front and rear sides) of the housing 4, thereby supporting the noise-reducing cover 74 with the axis of the second noise-reducing section 45 substantially aligned with the central axis 49.

[0048] Figure 7 This is a longitudinal sectional view showing the third noise reduction section of the vacuum cleaner body according to the first embodiment. In the electric suction unit 42 (see reference...) Figure 6 The ventilation passage 41 downstream (the other end) of the airflow direction includes: an upstream ventilation passage 82 connected to the other end of the electric suction machine 42; a midstream ventilation passage 83 surrounding the outer side of the upstream ventilation passage 82; a downstream ventilation passage 84 surrounding the outer side of the midstream ventilation passage 83; a first deflection section 86 that deflects air flowing out from the other end opening 85 of the other end of the upstream ventilation passage 82 and directs it to the midstream ventilation passage 83; and a second deflection section 87 that deflects air flowing out from the one end opening of the one end of the midstream ventilation passage 83 and directs it to the downstream ventilation passage 84. The downstream ventilation passage 84 communicates with a plurality of exhaust ports 32. In addition, the interior space of the downstream ventilation passage 84 and the handle 6 is blocked by a baffle plate 51, but it is also possible to leave a partial opening in the baffle plate 51 to allow communication between the interior space of the downstream ventilation passage 84 and the handle 6 (see reference). Figure 5 ).

[0049] The third noise reduction unit 46 includes a noise reduction pipe 88 and a noise reduction cover 89 forming an upstream ventilation path 82. The noise reduction pipe 88 has a straight pipe portion 91 (hereinafter referred to as "first pipe 91") and a tapered portion 92 whose opening widens towards the upstream side (one end side) in the airflow direction. The tapered portion 92 is provided on the upstream side (one end side) in the airflow direction of the noise reduction pipe 88. The opening 88a at the end of the tapered portion 92 with the largest opening is connected to the other end of the electric suction cover 47, and the other end of the tapered portion 92 with the smallest opening is connected to one end of the straight pipe portion 91. The other end opening 85 of the other end side of the straight pipe portion 91 opens towards the closed end 93 within the first foldback portion 86. The noise reduction cover 89 covers the outer periphery of the straight pipe portion 91.

[0050] The space between the straight pipe section 91 and the noise reduction cover 89 becomes the expansion chamber 89a. The third noise reduction section 46 is configured to reduce the noise generated by the electric suction machine 42 (see reference). Figure 6 The noise from the drive sound (high-frequency sound) of the electric suction machine 42 transmitted to the third noise reduction section 46 is reduced. The high-frequency sound from the electric suction machine 42 passing through the cone 92 is reflected and attenuated by the conical inner surface of the cone 92, which has a smaller cross-sectional area downstream in the direction of airflow. The attenuated sound waves are guided into the straight tube section 91 and then into the expansion chamber 89a through multiple through holes 91a of the straight tube section 91. Due to the interference of sound waves in the expansion chamber 89a, the noise is partially reduced. As a result, the noise level leaking to the outside of the housing 4 is reduced. In addition, the length from one end of the cone 92 to the other end is longer than the length of the electric suction machine 42 in the longitudinal direction. In this way, by making the length of the cone 92 longer, the angle of the cone of the cone 92 can also become gentler, thus improving the attenuation effect of high-frequency sound.

[0051] A pair of spacers 90 are provided between the outer surface (front and rear sides) of the conical portion 92 of the third noise reduction section 46 and the inner surface (front and rear sides) of the housing 4, thereby supporting the conical portion 92 with its axis aligned with the central axis 49. The entire straight tube portion 91 of the third noise reduction section 46 and the other end of the conical portion 92 are covered by a cylindrical member 94 (hereinafter referred to as "second tube 94"). The opening at one end of the cylindrical member 94 is connected to the outer surface of the conical portion 92, and the other end has a closed end 93. Furthermore, a pair of spacers 95 are provided between the outer surface (front and rear sides) of the other end, located in the middle of the direction of the central axis 49 of the cylindrical member 94, and the inner surface (front and rear sides) of the housing 4, thereby supporting the cylindrical member 94 with its axis aligned with the central axis 49. Furthermore, a pair of spacers 96 are provided between the outer surface (front and rear sides) of the other end of the straight tube 91 of the third noise reduction section 46 and the inner surface (front and rear sides) of the cylindrical component 94, thereby supporting the straight tube 91 so that the axis of the straight tube 91 is substantially aligned with the central axis 49. In addition, the pair of spacers 96 and the pair of spacers 95 are small plate-shaped components, so air can flow through these spacers 96, 96, 95, 95.

[0052] Thus, the vacuum cleaner body 2 of this embodiment has a triple-tube structure in the portion downstream of the electric suction motor 42 in the airflow direction. This triple-tube structure has a first tube 91, a second tube 94 surrounding the first tube 91, and a housing 4 surrounding the second tube 94 (hereinafter referred to as "third tube 4") arranged on the central axis 49. In the ventilation path 41 of this triple-tube structure, the first tube 91 forms an upstream ventilation path 82, the first tube 91 and the second tube 94 form a midstream ventilation path 83, and the second tube 94 and the third tube 4 form a downstream ventilation path 84. One end of the midstream ventilation path 83 is closed by a dividing wall 104 provided on the outer surface of the cone 92 of the noise reduction tube 88.

[0053] like Figure 7 As shown, the first reversing portion 86 is the space between the opening 85 at the other end of the first tube 91 and the closed end 93 of the second tube 94. A dividing wall 80 is provided between the tapered portion 92 of the noise-reducing tube 88 and the housing 4. The second reversing portion 87 is the space surrounded by the housing 4, the dividing wall 80, and one end of the second tube 94. Air flowing from the upstream ventilation passage 82 through the first reversing portion 86 into the midstream ventilation passage 83 flows in the first flow direction A, and air flowing from the midstream ventilation passage 83 through the connecting portion 97 and the second reversing portion 87 into the downstream ventilation passage 84 flows in the second flow direction B. In this embodiment, the first flow direction A and the second flow direction B are parallel to each other and are in opposite directions.

[0054] The cylindrical component 94 is a hollow cylinder. The first flow direction A is parallel to the central axis 94p of the cylindrical component 94. The peripheral wall (the thick-walled portion 100 described later) at one end of the cylindrical component 94 separates the upstream ventilation passage 83 and the downstream ventilation passage 84. A connecting portion 97 is provided on the peripheral surface at one end of the cylindrical component 94. The connecting portion 97 has at least one connecting region 99 that penetrates the peripheral wall and connects the upstream ventilation passage 83 and the downstream ventilation passage 84. In this embodiment, the case where one connecting region 99 is a hole, i.e., the connecting region 99 is a connecting hole 98, is illustrated, but one connecting region 99 may also be formed by a group of multiple connecting holes. In addition, in this embodiment, the connecting portion 97 has multiple connecting holes 98 as multiple connecting regions 99, but the number of connecting regions 99 may also be one.

[0055] Figure 8 This is a perspective view of the cylindrical tube 94A of the cylindrical component 94 of the first embodiment, viewed from the oblique front side. Figure 9 This is a perspective view of the cylindrical tube 94A of the cylindrical component 94 in the first embodiment, viewed from a rear oblique angle. In this embodiment, the cylindrical component 94 includes: a cylindrical tube 94A having openings at one end and at the other end; and a cover 94B (see reference 1). Figure 7 The cylindrical tube 94A and the cover 94B are fitted together to form a closed end 93. Alternatively, the cylindrical tube 94A and the cover 94B can be made from a single component.

[0056] Figure 10 This is a view of the cylindrical component 94 of the first embodiment from the front side. Figure 11 Viewed from the left side Figure 10 The diagram of cylindrical component 94. Figure 12 Viewed from the rear side Figure 10 The diagram of cylindrical component 94. Figure 13 Viewed from one end side Figure 10 The diagram of cylindrical component 94. Figure 14 Viewed from the other end Figure 10 The diagram of cylindrical component 94. Figure 15 yes Figure 10 A cross-sectional view along line aa. Figure 16 yes Figure 10 BB line view of the cross section. Figure 17 yes Figure 10 The cross-sectional view along the cc line. The cylindrical tube 94A has a certain inner diameter from one end to the other end, and the outer diameter of the region near the middle of one end is larger than the outer diameter of other parts. That is, the thickness T of the larger outer diameter portion of the cylindrical tube 94A is thicker than the thickness of other parts, and in this embodiment, it is more than 3 times thicker.

[0057] like Figure 13 and Figure 14As shown, a plurality of connecting holes 98 are provided on the front side and the left and right side sides of the thickened portion 100 (hereinafter referred to as the thick-walled portion 100) of the cylindrical tube 94 (see reference). Figure 8 No connecting hole 98 is provided on the rear side of the thick-walled portion 100.

[0058] Viewed from the axis 94p of the cylindrical tube 94A, the outer surface of the thick-walled portion 100 is curved from the front side to the left and right sides, and the portion outside the curved surface of the left and right sides is flat. From the rear side to the vicinity of the boundary with the left and right sides, it is curved.

[0059] Figures 15-18 The longitudinal section obtained by cutting the cylindrical tube 94A along its long side is shown. The extending direction of the connecting hole 98 is inclined relative to the thickness T of the thick-walled portion 100, which is the thickness direction. The connecting hole 98 has a first opening 101 that opens into the mid-side ventilation passage 83 and a second opening 102 that opens into the downstream side ventilation passage 84. The first opening 101 and the second opening 102 have the same shape and size, and the connecting hole 98 extends through the thick-walled portion 100 from the first opening 101 to the second opening 102 with the same shape and size.

[0060] Furthermore, the first opening 101, which connects to the midstream ventilation passage 83, and the second opening 102, which connects to the downstream ventilation passage 84, are positioned differently in the first airflow direction A within the midstream ventilation passage 83. In this embodiment, the first opening 101 is positioned upstream of the second opening 102 in the first airflow direction A. Moreover, as... Figure 18 As shown, the first opening 101 and the second opening 102 do not overlap each other in the direction of thickness T. Alternatively, the first opening 101 and the second opening 102 may partially overlap each other in the direction of thickness T. The above-described configuration of the connecting hole 98 applies to all connecting holes 98.

[0061] Air flowing along the first flow direction A in the midstream ventilation duct 83 flows into the plurality of connecting holes 98 from the first opening 101 and flows out into the downstream ventilation duct 84 from the second opening 102. At this time, the connecting holes 98 are inclined (non-parallel) with respect to the thickness T. Therefore, compared with the case where the connecting holes 98 are parallel with respect to the thickness T, the distance from the first opening 101 to the second opening 102 of the connecting holes 98 is longer. Therefore, the total surface area of ​​the inner surface of the connecting holes 98 increases. As a result, the contact area between the air passing through the connecting holes 98 and the inner surface of the connecting holes 98 increases, which can reduce the noise flowing out from the second opening 102 into the downstream ventilation duct 84. In addition, on the inner surface of the cylindrical tube 94A, there is no step difference that hinders airflow on the upstream side of the first flow direction A of the thick-walled portion 100, so air can flow smoothly into each connecting hole 98 from the first opening 101.

[0062] A small protrusion 103 is provided at the periphery of the second opening 102 on the outer surface of the thick-walled portion 100. The small protrusion 103 is located downstream of the first flow direction A in the periphery of the second opening 102. The small protrusion 103 protrudes from the periphery of the second opening 102 toward the interior of the downstream ventilation passage 84. Hereinafter, the protrusion of the small protrusion 103 will be described in detail, taking the small protrusion 103 provided at the periphery of the second opening 102 on the front side as an example. Figure 10 In this embodiment, the top of the small protrusion 103 protrudes away from the second opening 102. Here, the opening direction of the second opening 102 is a direction orthogonal to the opening surface of the second opening 102, specifically referring to the direction passing through the center of the second opening 102. In this embodiment, the opening direction of the front side of the second opening 102 is consistent with the front-rear direction. Therefore, when viewed from the opening direction of the second opening 102, the top of the small protrusion 103 on the front side protrudes away from the second opening 102. Thus, in this embodiment, when viewed from the opening direction of the second opening 102, the top of the small protrusion 103 protrudes away from the second opening 102. In other words, when viewed from the opening direction of the second opening 102, the small protrusion 103 protrudes towards the outside of the second opening 102. This small protrusion 103 blocks the second opening without obstructing the flow of air from the second opening to the downstream ventilation passage 84, and contacts the vortex of air flowing out from the second opening 102 into the downstream ventilation passage 84, thereby refining the vortex. This reduces the noise flowing from the second opening 102 into the downstream ventilation path 84.

[0063] like Figure 18 As shown, the inner surface of the connecting hole 98 has a first inclined surface 98x on the upstream side of the first flow direction A and a second inclined surface 98y on the downstream side of the first flow direction A. A small protrusion 103 is provided at the edge of the second opening 102 on the side of the second inclined surface 98y. Moreover, the small protrusion 103 has an inclined surface 103a that is continuous with the second inclined surface 98y. The inclination angle θ of the second inclined surface 98y and the inclined surface 103a with respect to the direction of thickness T is preferably an acute angle, and the angle θ is preferably 45 degrees or less.

[0064] Figure 19 yes Figure 8 Enlarged view. The small protrusion 103 has the appearance of a plate-like triangle whose thickness gradually decreases towards the top, and the longitudinal section of this plate-like triangle is an isosceles triangle (see reference). Figure 18 The acute angle of the isosceles triangle of the small protrusion 103 becomes the apex, and the longer side of the isosceles triangle becomes the inclined surface 103a. With the axis 94p as the central axis, the radial length of the small protrusion 103, i.e., the height H of the small protrusion 103 from the outer surface of the thick-walled portion 100 (refer to...). Figure 18The length L of the small protrusion 103 in the axial direction 94p is (refer to...) Figure 18 The preferred diameter is approximately 1mm to 4mm, more preferably less than 2mm. The circumferential length of the small protrusion 103, with the axis 94p as the central axis, is the width W1 of the bottom side of the small protrusion 103 (refer to...). Figure 13 , Figure 14 The preferred diameter is approximately 0.5mm to 0.9mm, and the width W2 of the top side of the small protrusion 103 (refer to...) Figure 14 The preferred diameter is approximately 0.1 mm to 0.5 mm. Furthermore, the preferred aspect ratio (H / W2) is ≥1 and W2 / W1 is ≥1 / 3. A plurality of small protrusions 103 are provided around the periphery of the second opening 102. The structure and configuration of the aforementioned small protrusions 103 apply to all small protrusions 103.

[0065] return Figure 10 The second opening 102 of the connecting hole 98 located on the front side of the cylindrical tube 94A is elongated, and this elongated shape is in the second flow direction B of the airflow in the downstream ventilation passage 84 and in the direction of the thickness T (refer to...). Figure 15 Orthogonal length directions ( Figure 10 The second opening 102 of the connecting hole 98 extends in the direction of arrow Q. The periphery of the second opening 102 upstream of the second flow direction B is not parallel to the length direction (arrow Q). The second opening 102 of the connecting hole 98 on the front side is formed as an arch protruding upstream of the second flow direction B. The middle portion of the second opening 102 on the front side is located upstream of the second flow direction B compared to its two ends in the length direction (arrow Q). The connecting hole 98 penetrates the thick-walled portion 100.

[0066] The first opening 101 is an arch with the same shape and size as the second opening 102. The first opening 101 and the second opening 102 may differ. For example, the width W3 of the first flow direction A of the arch of the first opening 101 may differ from the width W4 of the second opening 102 (see reference). Figure 18 Alternatively, the shape of the first opening 101 may be other than an arch (e.g., an elongated oval or ellipse in the direction of arrow Q).

[0067] The periphery of the upstream side of the second opening 102 of the connecting hole 98 in the second flow direction B is not parallel to the long side direction (it is orthogonal to the second flow direction B). Therefore, the flow direction of the vortex formed when flowing out of the second opening 102 is not parallel to the second flow direction B. In addition, by bending the second opening 102, the flow direction of the vortex formed when flowing out of the second opening 102 is dispersed. As a result, the refinement of the vortex can be promoted, and noise reduction can be achieved.

[0068] By bending the cylindrical thick-walled portion 100 in a circumferential direction centered on the axis 94p, the direction of the vortex formed by the air flowing out of the second opening 102 is more easily dispersed compared to the case where the connecting hole is provided on the flat surface of the square thick-walled portion. Therefore, the noise reduction effect can be improved.

[0069] In this embodiment, the connecting portion 97 has a plurality of connecting holes 98 on its front side. The plurality of connecting holes 98 are arranged at approximately equal intervals in the first flow direction A. The plurality of connecting holes 98 are provided on the side opposite to the plurality of discharge ports 32 (front side). Furthermore, the number of connecting holes 98 on the front side may be one to five or more.

[0070] like Figure 11 and Figure 13 As shown, the second opening 102 of the connecting hole 98 located on the left side of the cylindrical tube 94A has a shape having a curved portion 111 and a straight portion 112. The curved portion 111 extends along the outer surface of the cylindrical tube 94A from the upstream side to the downstream side in the second flow direction B, in a circumferential direction centered on the central axis 49, from the left side of the cylindrical tube 94A toward the front side of the cylindrical tube 94A. The curved portion 111 bends in such a way that it protrudes along the outer surface of the cylindrical tube 94A toward the downstream side of the second flow direction B. The straight portion 112 extends along the outer surface of the cylindrical tube 94A from the end of the curved portion 111 on the upstream side of the second flow direction B in a direction orthogonal to the second flow direction B. In this embodiment, the curved portion 111 is formed on the curved surface of the left side of the cylindrical tube 94A, but the curved portion 111 may also be formed on the plane of the cylindrical tube 94A. In this embodiment, the straight portion 112 is formed on the plane of the left side of the cylindrical tube 94A, but the straight portion 112 may also be formed on the curved surface of the cylindrical tube 94A. The connecting portion 97 has a plurality of connecting holes 98 on the left side. The plurality of connecting holes 98 on the left side are arranged at approximately equal intervals in the first flow direction A. The number of connecting holes 98 located on the left side may be 1 to 5 or more.

[0071] like Figure 13 and Figure 15As shown, the second opening 102 of the connecting hole 98 located on the right side of the cylindrical tube 94A has a shape having a curved portion 111 and a straight portion 112. The curved portion 111 extends along the outer surface of the cylindrical tube 94A from the upstream side to the downstream side in the second flow direction B, circumferentially from the right side of the cylindrical tube 94A towards the front side of the cylindrical tube 94A, centered on the central axis 49. The curved portion 111 bends in such a way that it protrudes along the outer surface of the cylindrical tube 94A towards the downstream side of the second flow direction B. The straight portion 112 extends along the outer surface of the cylindrical tube 94A from the end of the curved portion 111 on the upstream side of the second flow direction B in a direction orthogonal to the second flow direction B. In this embodiment, the curved portion 111 is formed on the curved surface of the right side of the cylindrical tube 94A, but the curved portion 111 may also be formed on the plane of the cylindrical tube 94A. In this embodiment, the straight portion 112 is formed on the plane of the right side of the cylindrical tube 94A, but the straight portion 112 may also be formed on the curved surface of the cylindrical tube 94A. The connecting portion 97 has a plurality of connecting holes 98 on the right side. The plurality of connecting holes 98 on the right side are arranged at approximately equal intervals in the first flow direction A. The number of connecting holes 98 located on the right side may be 1 to 5 or more.

[0072] like Figure 10 and Figure 11 As shown, a plurality of small protrusions 103 are provided in the second opening 102 of the connecting hole 98. The plurality of small protrusions 103 are provided on the periphery of the second opening 102 of the connecting hole 98 in the first flow direction A. On two connecting holes 98 adjacent to the first flow direction A, the plurality of small protrusions 103 provided along the periphery of the second opening 102 of one connecting hole 98 and the plurality of small protrusions 103 provided along the periphery of the second opening 102 of the other connecting hole 98 are aligned in the first flow direction A.

[0073] return Figure 7 The downstream ventilation passage 84 is the space between the cylindrical component 94 and the housing 4 on the side opposite to the second fold-back portion 87. A sheet-like sound-absorbing material 105 made of materials such as foamed polyurethane or velvet is provided in the downstream ventilation passage 84. In this embodiment, the sound-absorbing material 105 is adhered to the outer surface of the cylindrical component 94 (excluding the connecting portion 97) and the inner surface of the housing 4 (excluding the outlet 32). By providing the sound-absorbing material 105 in the downstream ventilation passage 84, noise reduction can also be achieved in the downstream ventilation passage 84. In particular, it is preferable to provide the sound-absorbing material 105 on the inner surface of the housing 4 opposite to the connecting portion 97, as this is beneficial for noise reduction.

[0074] Air flowing through the upstream ventilation path 82 within the third noise reduction section 46 flows into the first return section 86, returns to the first return section 86, and flows into the midstream ventilation path 83. It then flows into the second return section 87 through the multiple connecting holes 98 of the connecting section 97. At this time, air is discharged from the multiple connecting holes 98 in a tilted direction relative to the sound-absorbing material 105 provided on the inner surface of the housing 4. It is reflected by the inner surface of the housing 4 and faces the dividing wall 80, then reflected by the dividing wall 80 (and returned by the second return section 87) and flows through the downstream ventilation path 84. The air flowing into the downstream ventilation path 84 is then discharged to the outside through the multiple exhaust ports 32.

[0075] Thus, according to the electric vacuum cleaner 1 (refer to...) Figure 1 The noise reduction is achieved through the noise reduction of the intake body-side noise reduction section 24, the noise reduction of the first noise reduction section 44, the noise reduction of the second noise reduction section 45, the noise reduction of the third noise reduction section 46, the noise reduction of the connecting section 97, the noise reduction of the sound-absorbing material 105 of the downstream ventilation passage 84, and the noise reduction of the long exhaust passage formed by the two reversing sections (first reversing section 86 and second reversing section 87) between the other end opening 85 of the third noise reduction section 46 and the exhaust outlet 32. The drawn-in air is discharged from the exhaust outlet 32 ​​through the air supply structure with multiple parts having a noise reduction effect. Therefore, compared with the case where the air supply structure of this embodiment does not have a noise reduction effect, an electric vacuum cleaner with improved noise reduction effect and lower operating noise can be realized. At this time, the first noise reduction section 44, the dust collection section 43, the second noise reduction section 45, the electric suction motor 42, and the third noise reduction section 46 are arranged on the same central axis 49 in the housing 4, so exhaust loss can be suppressed to a low level while maintaining suction performance.

[0076] like Figure 6 and Figure 7 As shown, in this embodiment, the through hole 71c of the first noise reduction part 44 is oblong, the through hole 75a of the second noise reduction part 45 is oblong, and the through hole 91a of the third noise reduction part 46 is lattice-shaped. However, the shape of these through holes is not particularly limited and can be elliptical, triangular, quadrilateral, or other polygonal or amorphous shapes. Furthermore, the range of these through holes is not particularly limited; it can be a full circumference or a partial circumference spanning the entire length of the noise reduction tube, or a range from near one end of the noise reduction tube to near the other end, or from one end of the noise reduction tube to the other end. In this embodiment, these through holes penetrate the noise reduction tube in a direction perpendicular to the central axis 49, but the through holes can also penetrate the noise reduction tube in a direction inclined to the central axis 49.

[0077] Furthermore, preferably, the electric suction head cover 47 is mounted to the noise reduction cover 74 of the second noise reduction section 45 and the conical portion 92 of the noise reduction tube 88 of the third noise reduction section 46 via elastic members such as rubber. This reduces the transmission of vibrations from the electric suction head 42 to the noise reduction cover 74 and the conical portion 92. Additionally, preferably, the spacers 78, 90, and 96 are mounted to the inner surface of the housing 4 via elastic members such as rubber. This also reduces the transmission of vibrations from the electric suction head 42 to the housing 4.

[0078] (Second Embodiment) In the first embodiment, an arched shape of the connecting hole 98 is illustrated, but the shape of the connecting hole 98 is not limited to an arch; for example, it can also be circular. Furthermore, in the first embodiment, a connecting region 99 is illustrated by forming a single connecting hole 98, but the connecting region 99 can also be formed by a group of multiple connecting holes 98. Therefore, an arched connecting region 99 protruding upstream in the second flow direction B can also be formed by a group of multiple connecting holes 98.

[0079] (Third implementation method) In the first embodiment, the small protrusion 103 of the connecting portion 97 is shown to be in the shape of a plate-like triangle. However, the shape of the small protrusion 103 is not particularly limited, and it can be, for example, a triangular pyramid, a triangular prism, a square pyramid, a square prism, a cone, a cylinder, etc. When the small protrusion 103 is a triangular pyramid or a square pyramid, one side of the triangular pyramid or square pyramid can face the connecting hole 98, and the inclination angle of that side can be angle θ. When the small protrusion 103 is a triangular prism or a square prism, one side of the triangular prism or square prism can be positioned on the side of the connecting hole 98.

[0080] (Fourth Embodiment) In the first embodiment, an example is shown where air passing through the upstream ventilation path 82 in the third noise reduction section 46 flows into the plurality of communication holes 98 of the communication section 97 via the first return section 86 and the midstream ventilation path 83, and is discharged from the plurality of communication holes 98 in an inclined direction relative to the inner surface of the housing 4 towards one end. However, air can also be discharged from the plurality of communication holes 98 in an inclined direction relative to the inner surface of the housing 4 towards the other end. That is, the inclination direction of the communication holes 98 relative to the thickness T can also be the opposite direction.

[0081] (Fifth Embodiment) In the first embodiment, an example is shown where a connecting portion 97 is provided in an air supply structure having a triple-pipe structure comprising a first pipe 91, a second pipe 94, and a third pipe 4 (see reference). Figure 7 ), but it can also be Figure 20 The air supply structure 200 shown is provided with a connecting part 203. Figure 20This is an explanatory diagram showing the air supply structure of the fifth embodiment. This air supply structure 200 can be installed in ventilation paths of electric air supply devices that spray air, such as stick-type, handheld type, can type, and upright electric vacuum cleaners (suction vacuum cleaners), electric blowers, etc., and sprayers that spray air streams mixed with liquid.

[0082] The air supply structure 200 has a connecting portion 203 on its peripheral wall and includes: a first ventilation passage 201 that allows air drawn in through an air intake (not shown) to flow through the connecting portion 203 in a first flow direction A; and a second ventilation passage 202 that allows fluid (e.g., air) flowing in from the connecting portion 203 to flow through an exhaust port (not shown) in a second flow direction B. The downstream side of the first ventilation passage 201 and the upstream side of the second ventilation passage 202 are adjacent to each other in parallel, separated by a peripheral wall 204 (hereinafter referred to as partition wall 204) 204. Alternatively, the upstream side of the first ventilation passage 201 and the downstream side of the second ventilation passage 202 may extend in different directions.

[0083] The downstream side of the first ventilation passage 201 is closed by a sealing plate 201a, and the upstream side of the second ventilation passage 202 is closed by a sealing plate 202a. A thick-walled portion 205 is provided on the sealing plate 201a side of the partition wall 204, and a connecting portion 203 is provided on the thick-walled portion 205. One or more (four in this case) connecting holes 206 are provided on the connecting portion 203. The connecting holes 206 are inclined relative to the thickness T of the thick-walled portion 205. The first opening 207 on the first ventilation passage 201 side of the connecting hole 206 is positioned upstream of the second opening 208 on the second ventilation passage 202 side of the connecting hole 206 in the first flow direction A.

[0084] One or more small protrusions 209 are provided on the periphery of the upstream side of the second flow direction B of the second opening 208. In the fifth embodiment, the structure (shape, size, etc.) of the connecting hole 206 and the small protrusions 209 can be the same as in the first, second, or third embodiments. In addition, in the fifth embodiment, the inclination direction of the connecting hole 206 is the same as in the fourth embodiment, and can be reversed. According to the air supply structure 200 of the fifth embodiment, the ventilation noise generated at the part where fluid (e.g., air) flowing through the first ventilation passage 201 in the first flow direction A is supplied to the second ventilation passage 202 in the second flow direction B opposite to the first flow direction A via the connecting portion 203 can be reduced.

[0085] (Sixth Implementation Method) Figure 21This is an explanatory diagram showing the air supply structure of the sixth embodiment. The air supply structure 300 of the sixth embodiment has a connecting portion 303 on its peripheral wall, and includes a first ventilation path 301 through which air drawn in from an air intake (not shown) flows into the connecting portion 303 in a first flow direction A, and a second ventilation path 302 through which fluid (e.g., air) flowing in from the connecting portion 303 flows into an exhaust port (not shown) in a second flow direction B. The downstream side of the first ventilation path 301 and the upstream side of the second ventilation path 302 extend parallel to each other across a peripheral wall 304 (hereinafter referred to as a partition wall 304) 304. Alternatively, the upstream side of the first ventilation path 301 and the downstream side of the second ventilation path 302 may extend in different directions.

[0086] The downstream side of the first ventilation passage 301 is closed by a sealing plate 301a, and the upstream side of the second ventilation passage 302 is closed by a sealing plate 302a. A thick-walled portion 305 is provided on the sealing plate 302a side of the partition wall 304, and a connecting portion 303 is provided in the thick-walled portion 305. One or more (four in this case) connecting holes 306 are provided in the connecting portion 303. The connecting holes 306 are inclined relative to the thickness T of the thick-walled portion 305. The first opening 307 on the first ventilation passage 301 side of the connecting hole 306 is positioned upstream of the second opening 308 on the second ventilation passage 302 side of the connecting hole 306 in the first flow direction A.

[0087] One or more small protrusions 309 are provided on the periphery of the upstream side of the second flow direction B of the second opening 308. In the sixth embodiment, the structure (shape, size, etc.) of the connecting hole 306 and the small protrusions 309 can be the same as in the first, second, or third embodiments. In addition, in the sixth embodiment, the inclination direction of the connecting hole 306 is the same as in the fourth embodiment, and can be reversed. According to the air supply structure 300 of the sixth embodiment, the ventilation noise generated at the point where fluid flowing in the first ventilation passage 301 in the first flow direction A is supplied to the second ventilation passage 302 in the second flow direction B, which is in the same direction as the first flow direction A, can be reduced.

[0088] In a preferred embodiment of the present invention, there is also a combination of any of the above-described embodiments. Besides the embodiments described above, various modifications are possible with respect to the present invention. These modifications should be understood to fall within the scope of the present invention. The present invention should include all modifications within the scope of the claims and their equivalent meanings.

Claims

1. An air supply structure, characterized in that, include: The first ventilation path has a connecting part on its peripheral wall, through which air drawn in from the intake port flows. as well as The second ventilation path allows air flowing in from the connecting section to circulate towards the exhaust port. The connecting portion has at least one connecting hole that penetrates the peripheral wall and connects the first ventilation path with the second ventilation path. The connecting hole is inclined relative to the thickness direction of the peripheral wall.

2. The air supply structure according to claim 1, characterized in that, The first opening in the connecting hole that is connected to the first ventilation path and the second opening in the connecting hole that is connected to the second ventilation path are located in different positions in the first ventilation path, i.e., in the first flow direction.

3. The air supply structure according to claim 2, characterized in that, The first opening is located upstream of the second opening in the first flow direction.

4. The air supply structure according to claim 3, characterized in that, The connecting hole has a small protrusion that protrudes from the periphery of the second opening into the interior of the second ventilation passage.

5. The air supply structure according to claim 4, characterized in that, The small protrusion protrudes from the periphery on the upstream side of the second flow direction of airflow within the second ventilation path.

6. The air supply structure according to claim 4, characterized in that, When viewed from the opening direction of the second opening, the small protrusion protrudes away from the second opening.

7. The air supply structure according to claim 4, characterized in that, The small protrusion has an inclined surface that is continuous with the inclined inner surface of the communicating hole.

8. The air supply structure according to claim 7, characterized in that, The first ventilation path is a hollow cylindrical shape.

9. The air supply structure according to claim 8, characterized in that, The second opening is a long strip shape extending in the second flow direction of the second ventilation path and the length direction orthogonal to the thickness direction, and the second opening is not parallel to the length direction.

10. The air supply structure according to claim 9, characterized in that, The middle portion of the second opening in the length direction is located upstream of the second flow direction, which is closer to the two ends in the length direction than the two ends in the length direction.

11. An electric vacuum cleaner, characterized in that, include: The air intake section has an air intake port; The discharge section has a discharge port; The air supply section draws in air from the air inlet and sends it to the air outlet section, and discharges it from the air outlet. as well as The dust removal unit removes dust from the air drawn in by the intake unit. The discharge section has the air supply structure according to any one of claims 1 to 10.

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