Electric vacuum cleaner

Abstract

This electric vacuum cleaner comprises a housing which has an intake port and an exhaust port, a handle which is provided in the housing, a ventilation passage through which air from the intake port flows to the exhaust port, and an electric suction machine which is provided in the ventilation passage, wherein: the ventilation passage downstream of the electric suction machine in the airflow direction includes a first ventilation passage which is provided within the housing, a second ventilation passage which is provided within the handle and which communicates with an end portion of the first ventilation passage on the downstream side in the airflow direction, and a third ventilation passage which is provided within the housing and which communicates with an end portion of the second ventilation passage on the downstream side in the airflow direction; the intake port is disposed on one end side of the housing in a central axis direction; the exhaust port is disposed closer to the other end side than the intake port in the direction of the central axis and closer to the one end side than the third ventilation passage; the handle is disposed on the other end side of the housing; and the distance in the central axis direction from the end portion of the second ventilation passage on the downstream side to the part of the exhaust port that is closest to the end portion of the third ventilation passage on the downstream side in the airflow direction is equal to or greater than half the length of the second ventilation passage in the direction of the central axis.

Description

vacuum cleaner

[0001] This application claims priority to Japanese Patent Application No. 2023-169857, filed on September 29, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 discloses a handheld cleaner including a main housing containing an electric fan (motor and fan), a dust case having a nozzle and removably attached to the front end of the main housing, a filter device attached to the front end of the main housing and housed in the dust case, and a handle attached to the rear end of the main housing. In this cleaner, the interior of the handle forms a part of the ventilation passage, and a second opening is provided downstream of the handle in the airflow direction, and a third opening is provided upstream of the second opening in the airflow direction. When the electric fan is driven for cleaning, dust-laden air flows into the dust case from the nozzle's air intake path by suction force, where the dust is captured by the filter device. The air that passes through the filter device and the electric fan flows through the main housing, into the handle, and is discharged to the outside through the third and second openings.

[0003] This cleaner is designed so that air passes through the handle and is exhausted through the exhaust ports (second and third openings) in the handle, thereby increasing the length of the ventilation path from the electric fan to the exhaust port. As a result, noise, including the driving sound of the electric fan and airflow, is attenuated as it passes through the increased ventilation path, resulting in quieter operation.

[0004] WO2020 / 189226 publication

[0005] In the cleaner of Patent Document 1, some of the air passing through the handle flows toward the rear end of the main housing, turns back toward the front end, and is discharged to the outside through the second opening, thereby making the cleaner more compact in the front-to-rear direction. However, this makes it difficult to make the ventilation path length from the electric fan to the second opening long enough to achieve sufficient distance attenuation of noise and thereby reduce noise levels.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide an electric vacuum cleaner that has been made in consideration of the above circumstances.

[0007] The present invention provides an electric vacuum cleaner comprising: a housing having an air intake port and an exhaust port; a handle provided in the housing; an air passage through which air from the air intake port flows to the exhaust port; and an electric suction device provided in the air passage; the air passage downstream of the electric blower in the airflow direction has a first air passage provided in the housing; a second air passage provided in the handle and communicating with the downstream end of the first air passage in the airflow direction; and a third air passage provided in the housing and communicating with the downstream end of the second air passage in the airflow direction; the air intake port is located at one end side in the direction of the central axis of the housing; the exhaust port is located at the other end side of the air intake port in the direction of the central axis and at one end side of the third air passage; the handle is located at the other end side of the housing; and the distance in the direction of the central axis from the downstream end of the second air passage to the part of the exhaust port closest to the downstream end of the third air passage in the airflow direction is at least half the length in the direction of the central axis of the second air passage.

[0008] The present invention also provides an electric vacuum cleaner comprising a vacuum cleaner body including a housing having an air intake port and an exhaust port, a hollow handle connected to the housing, an air passage through which air from the air intake port flows to the exhaust port, an electric suction device provided in the air passage, a dust collection unit provided in the air passage upstream of the electric suction device in the airflow direction, and a sound reduction unit that forms part of the air passage and reduces noise including airflow noise, wherein the interior of the handle forms part of the air passage, and the sound reduction unit includes at least a fourth sound reduction unit selected from the group consisting of a first sound reduction unit that forms part of the air passage upstream of the dust collection unit in the airflow direction and reduces noise including airflow noise, a second sound reduction unit that forms part of the air passage between the dust collection unit and the electric suction device and reduces noise including noise caused by driving the electric suction device, a third sound reduction unit that forms part of the air passage downstream of the electric suction device in the airflow direction and reduces noise including noise caused by driving the electric suction device, and a fourth sound reduction unit that forms part of the air passage in the handle and reduces noise including airflow noise.

[0009] According to the electric vacuum cleaner of the present invention, it is possible to reduce noise while suppressing a decrease in suction performance.

[0010] 1 is a perspective view showing a first embodiment of a vacuum cleaner according to the present invention; FIG. 2 is a longitudinal sectional view showing a suction port body of the vacuum cleaner according to the first embodiment; FIG. 3 is a longitudinal sectional view showing a vacuum cleaner body of the vacuum cleaner according to the first embodiment; FIG. 4 is a perspective view of the vacuum cleaner according to the first embodiment, seen from diagonally front; FIG. 5 is a perspective view of the vacuum cleaner according to the first embodiment, seen from diagonally rear; FIG. 6 is a longitudinal sectional view showing the suction port body-side sound reduction section of the suction port body and the first and second sound reduction sections of the vacuum cleaner body of the first embodiment; FIG. 7 is a longitudinal sectional view showing the third sound reduction section of the vacuum cleaner body of the first embodiment; FIG. 8 is a longitudinal sectional view showing the vicinity of the handle of the vacuum cleaner body of the first embodiment; FIG. 9 is a perspective view of a second embodiment of a vacuum cleaner according to the present invention; FIG. 10 is a longitudinal sectional view showing the vacuum cleaner according to the second embodiment; FIG. 11 is a longitudinal sectional view showing the vicinity of the handle of the vacuum cleaner body of the second embodiment; FIG. 12 is a longitudinal sectional view showing the vicinity of the handle of the vacuum cleaner body of the third embodiment; FIG. 13 is a longitudinal sectional view showing the vicinity of the handle of the vacuum cleaner body of the third embodiment; 10A and 10B are vertical cross-sectional views showing the vicinity of a handle in a vacuum cleaner body of a fifth embodiment, and Fig. 10B are vertical cross-sectional views showing the vicinity of a handle in a vacuum cleaner body of a sixth embodiment.

[0011] The present invention will be described in more detail below with reference to the accompanying drawings. Note that the following description is given by way of example only in all respects and should not be construed as limiting the present invention.

[0012] (First Embodiment) Fig. 1 is a perspective view showing a first embodiment of a vacuum cleaner 1 according to the present invention. The vacuum cleaner 1 is a stick-type vacuum cleaner including a vacuum cleaner main body 2 and a suction inlet body 3 detachably connected to the vacuum cleaner main body 2. Fig. 1 shows the vacuum cleaner 1 in a state when cleaning a floor F. At this time, when a user holds a handle 6 provided on an upper end 5b of a housing 4 of the vacuum cleaner main body 2, the vacuum cleaner 1 is in a state in which the suction inlet body 3 is positioned at the forward-most position, the handle 6 is positioned at the rearmost position, and the vacuum cleaner main body 2 is tilted backward from the lower end 5a to the upper end 5b. In the following description, the lower end 5a of the vacuum cleaner main body 2 shown in Fig. 1 may be referred to as one end 5a, and the upper end 5b may be referred to as the other end 5b.

[0013] In this embodiment, the housing 4 is generally cylindrical, but is not limited to a cylindrical shape. It may be partially or entirely rectangular or have a polygonal cross section. In this embodiment, the handle 6 is annular, more specifically, oval when viewed from the left and right, and stick-shaped when viewed from the front and rear. An operating unit (not shown) is provided on the front surface 7 around the oval hole in the handle 6. The operating unit has multiple push-button switches, allowing the user to adjust the output of the electric suction device 42 (see FIG. 4 ) (e.g., switch between on and off, weak mode and strong mode). Because the handle 6 is annular (oval), the user can smoothly move their hand to a comfortable grip on the handle 10 depending on the tilt angle α (see FIG. 4 ) of the vacuum cleaner 1 relative to the floor surface F.

[0014] 2 is a vertical cross-sectional view showing the suction port body 3 of the electric vacuum cleaner 1 of the first embodiment. The suction port body 3 has a suction port main body 21 placed on the floor surface F, a joint portion 22 connected to the suction port main body 21, and a connection pipe portion 23 connected to the joint portion 22. A suction port 25 is provided at the bottom of the suction port main body 21, a connection port 26 is provided at the end of the connection pipe portion 23, and an air passage 27 is provided inside the suction port body 3 to connect the suction port 25 and the connection port 26. Because the connection pipe portion 23 is connected to the suction port main body 21 via the joint portion 22, the connection pipe portion 23 can rotate in the front-rear and left-right directions relative to the suction port main body 21.

[0015] FIG. 3 is a perspective view showing the vacuum cleaner body of the first embodiment. The housing 4 of the vacuum cleaner body 2 has an air intake 31 on its end surface near one end 9a. FIG. 3 shows the state in which the suction port body 3 has been removed from the air intake 31 of the vacuum cleaner body 2. The connecting pipe 23 (see FIG. 2) of the suction port body 3 is removably inserted into the air intake 31 of the vacuum cleaner body 2. The vacuum cleaner of this embodiment may be provided with attachments other than the suction port body 3. Examples of such attachments include a crevice nozzle, a brush nozzle, and a hose nozzle. Therefore, attachments other than the suction port body 3 can be attached and detached to the air intake 31 of the vacuum cleaner body 2. For example, when connecting a crevice nozzle to the vacuum cleaner body 2 to clean corners in a room or gaps between furniture, the user can easily move the crevice nozzle to the desired position by holding the handle 6 with one hand and supporting the rear surface of the housing 4 with the other hand. Furthermore, the electric vacuum cleaner of this embodiment may be provided with a battery mounting section (not shown) for detachably mounting a battery on the housing 4. For example, if the battery mounting section is provided on the rear surface at one end of the housing 4, the center of gravity is lowered by the battery being placed near the air intake 31, making it easier to handle the vacuum cleaner main body 2.

[0016] FIG. 4 is a longitudinal cross-sectional view of the vacuum cleaner of the first embodiment. In FIG. 4, reference numeral 49 denotes the central axis of the housing 4. The housing 4 has multiple small hole-shaped exhaust ports 32 on the peripheral surface on the other end 5b side. In this embodiment, when the vacuum cleaner 1 is used for cleaning, the multiple exhaust ports 32 are located on the rear surface of the housing 4. The multiple exhaust ports 32 may be located on at least one of the left and right side surfaces on the other end 5b side of the housing 4, or on at least one of the left and right side surfaces and the rear surface. Furthermore, the multiple exhaust ports 32 may be of the same size, or may be of three different sizes: large, medium, and small. If the multiple exhaust ports 32 are of different sizes, they may be arranged in groups of small (e.g., 0.5 to 1.0 mm), medium (e.g., 1.0 to 1.5 mm diameter), and large (e.g., 1.5 to 2.0 mm diameter) exhaust ports 32, arranged in order from the other end 5b. Furthermore, the exhaust ports 32 are not arranged in an area that overlaps with the electric suction device 42. By doing this, there is no exhaust port 32 facing and close to the sound-reducing cover 47 (described later) that covers the electric suction machine 42, so the noise leaking to the outside can be reduced compared to when there is an exhaust port 32 facing and close to the sound-reducing cover 47.

[0017] Fig. 5 is a perspective view of the electric vacuum cleaner of the first embodiment as seen obliquely from the front. Fig. 6 is a perspective view of the electric vacuum cleaner of the first embodiment as seen obliquely from the rear. As shown in Figs. 4 to 6 , the housing 4 includes an air passage 41 through which air from the air intake 31 flows to the air exhaust 32, an electric suction device 42 provided in the air passage 41, a dust collection unit 43 provided in the air passage 41 upstream of the electric suction device 42 in the airflow direction, a first sound reduction unit 44 provided in the air passage 41 between the air intake 31 and the dust collection unit 43, a second sound reduction unit 45 provided in the air passage 41 between the dust collection unit 43 and the electric suction device 42, and a third sound reduction unit 46 provided in the air passage 41 between the electric suction device 42 and the air exhaust 32. The electric suction device 42 is covered by an electric suction device cover 47.

[0018] The first sound reduction section 44 is disposed within the housing 4 and forms part of the ventilation passage 41 upstream of the dust collection section 43 in the airflow direction. The second sound reduction section 45 is disposed within the housing 4 and forms part of the ventilation passage 41 between the dust collection section 43 and the electric suction device 42. The third sound reduction section 46 is disposed within the housing 4 and forms part of the ventilation passage 41 downstream of the electric suction device 42 in the airflow direction. In this embodiment, the handle 6 is hollow, and the interior of the handle 6 also forms part of the ventilation passage 41.

[0019] FIG. 7 is a longitudinal cross-sectional view showing the suction port body-side sound attenuation section 24 of the suction port body 3 and the first and second sound attenuation sections 44 and 45 of the vacuum cleaner body 2 according to the first embodiment. The first sound attenuation section 44 includes a sound attenuation tube 71 and a sound attenuation cover 72 that covers the outer periphery of the sound attenuation tube 71. While the sound attenuation cover 72 partially covers the outer periphery of the sound attenuation tube 71 in FIG. 7 , it may cover the entire outer periphery of the sound attenuation tube 71. The sound attenuation tube 71 has a first end opening 71a connected to the air intake 31 and a second end opening 71b connected to the inlet 43a at one end of the dust collection section 43. The sound attenuation tube 71 has a ventilated structure on at least a portion of its periphery. In this embodiment, the ventilated structure of the sound attenuation tube 71 is a plurality of through holes 71c that penetrate the inner and outer surfaces of the sound attenuation tube 71. In addition, the breathable structure of the sound-reducing tube 71 may be a sound-absorbing material made of a breathable material (e.g., urethane foam) that covers the inner surface of the sound-reducing tube 71, in which case the sound-reducing tube 71 may not have multiple through holes 71c, and may not even have a sound-reducing cover 72.

[0020] The space between the sound-reducing tube 71 and the sound-reducing cover 72 forms an expansion chamber 71d. The first sound-reducing section 44 is configured to reduce noise, including ventilation noise (airflow noise) of air flowing from the air intake 31 to the first sound-reducing section 44. Noise from the air intake 31 is transmitted inside the sound-reducing tube 71 of the first sound-reducing section 44. The noise (sound waves) is introduced into the expansion chamber 71d through multiple through-holes 71c of the sound-reducing tube 71, and a portion of the noise is reduced by sound wave interference within the expansion chamber 71d. This reduces the level of noise leaking outside the housing 4. Because the first sound-reducing section 44 is provided in the ventilation passage 41 near the air intake 31 of the vacuum cleaner body 2, a sound-reducing effect can be achieved even when an attachment (such as a suction port body, crevice nozzle, brush nozzle, or hose nozzle) that does not have a sound-reducing section is attached to the vacuum cleaner body 2.

[0021] Returning to FIG. 2 , in this embodiment, the suction port body 21 of the suction port body 3 is provided with a suction port body-side sound-reducing section 24, thereby achieving a sound-reducing effect in the suction port body 3 as well. The suction port body 21 includes a lower case 21a, an upper case 21b, an upper cover 21c, a rotating brush 21d, and a drive motor (not shown) that rotates the rotating brush 21d. The suction port body-side sound-reducing section 24 has a plurality of through-holes 24a formed in the upper case 21b above the rotating brush 21d and an expansion chamber 24b, which is the space between the upper case 21b and the upper cover 21c. The plurality of through-holes 24a communicate with the expansion chamber 24b. In this suction port body 3, noise (sound waves), including the rotational sound of the rotating brush 21d and the ventilation sound of airflow passing through the suction port 25, are introduced into the expansion chamber 24b through the plurality of through-holes 24a, and a portion of the noise is reduced by sound wave interference within the expansion chamber 24b. This reduces the level of noise leaking outside the suction port body 3.

[0022] Returning to FIG. 7 , the dust collection unit 43 has an inlet 43a at one end through which dust-laden air flows in from the air intake 31, and an outlet 43b at the other end through which dust-free air is discharged to the second sound reduction unit 45. A dust collection bag or a dust collection device is housed in the internal space of the dust collection unit 43. In the case of a dust collection bag, a so-called paper bag is used, which stores dust in a breathable pack body. In the case of a dust collection device, if the dust collection device includes a container body and a filter, dust captured by the filter can be stored in the container body, and dust-free air can be exhausted from the exhaust port of the dust collection device. Alternatively, in the case of a cyclone-type dust collection device, it can be equipped with a cyclone unit including a centrifugal separator (inner cylinder) and a container body, and dust can be separated in the cyclone unit, the separated dust can be stored in the container body, and dust-free air can be exhausted from the exhaust port of the cyclone unit.

[0023] An openable lid (not shown) constituting part of the housing 4 is provided near the dust collection unit 43. The lid can be opened to remove a dust collection bag or dust collection device (dust collection container) from the dust collection unit 43 and dispose of the dust. The lid has a double structure in which a portion of the outer wall (housing 4) is integrated with a portion of the wall forming the dust collection unit 43. The dust collection bag or the like is removed by opening the lid. The double-layered lid also reduces noise during operation. To more effectively reduce wind noise (intake), a filter-type dust collection device or dust collection bag is preferable to a cyclone-type dust collection device. This is because a cyclone-type dust collection device increases wind speed in the cyclone section, increasing wind noise. Filter-type dust collection devices and dust collection packs do not have a cyclone section, so they can reduce wind noise (intake noise) more than a cyclone-type dust collection device.

[0024] The second sound reduction section 45 includes a sound reduction tube 73 and a sound reduction cover 74. The sound reduction tube 73 has a first end opening 73a connected to the discharge port 43b of the dust collection section 43 and a second end opening 73b connected to the suction port 42a of the electric suction machine 42. The sound reduction cover 74 only needs to cover at least a portion of the outer periphery of the sound reduction tube 73; in this embodiment, the sound reduction cover 74 covers the entire outer periphery of the sound reduction tube 73. The sound reduction tube 73 has a straight tube section 75 and a tapered section 76 whose opening widens toward the upstream side (one end) in the airflow direction. The tapered section 76 is located on the upstream side (one end) of the sound reduction tube 73 in the airflow direction. The first end opening 73a, which is the largest opening of the tapered section 76, connects to the other end of the peripheral wall that forms the dust collection section 43, and the other end, which is the smallest opening of the tapered section 76, connects to one end of the straight tube section 75. One end of the sound-reducing cover 74 is connected to the outer surface of the tapered portion 76 near one end opening 73 a , and the other end of the sound-reducing cover 74 is connected to one end side of the electric suction machine cover 47 that covers the electric suction machine 42 .

[0025] The straight pipe section 75 of the sound attenuation pipe 73 has a breathable structure on at least a portion of its peripheral surface. In this embodiment, the breathable structure of the straight pipe section 75 is a plurality of through holes 75a that penetrate the inner and outer surfaces of the straight pipe section 75. Note that the breathable structure of the straight pipe section 75 may also be a sound-absorbing material made of a breathable material (e.g., urethane foam) that covers the inner surface of the straight pipe section 75. In this case, the straight pipe section 75 does not need to have a plurality of through holes 75a, and further, the sound attenuation cover 74 may not be required.

[0026] The space between the sound-reducing tube 73 and the sound-reducing cover 74 forms an expansion chamber 77. The second sound-reducing section 45 is configured to reduce noise, including ventilation noise from air flowing from the dust collection section 43 to the second sound-reducing section 45 and driving noise (high-frequency noise) of the electric suction machine 42 transmitted from the electric suction machine 42 to the second sound-reducing section 45. Noise (sound waves) transmitted inside the sound-reducing tube 73 of the second sound-reducing section 45 are introduced into the expansion chamber 77 through the multiple through-holes 75a of the straight tube section 75, and a portion of the noise is reduced by sound wave interference within the expansion chamber 77. This reduces the level of noise leaking outside the housing 4. A pair of spacers 78 are provided between the outer surface (front and rear sides) of the sound-reducing cover 74 midway along the central axis 49 and the inner surface (front and rear sides) of the housing 4, thereby supporting the sound-reducing cover 74 with the axis of the second sound-reducing section 45 generally aligned with the central axis 49.

[0027] FIG. 8 is a longitudinal cross-sectional view showing the third sound reduction section 81 of the vacuum cleaner body of the first embodiment. FIG. 9 is a longitudinal cross-sectional view showing the handle and its vicinity in the vacuum cleaner body of the first embodiment. The ventilation passage 41 downstream (the other end) of the electric suction device 42 (see FIG. 4 ) in the airflow direction includes a first ventilation passage (a ventilation passage between the upstream first ventilation passage 82 and the downstream first ventilation passage 84) provided within the housing, a second ventilation passage 101 provided within the handle 6 and communicating with the downstream end of the first ventilation passage (the downstream first ventilation passage 84) in the airflow direction, and a third ventilation passage 102 provided within the housing 4 and communicating with the downstream end of the second ventilation passage 101 in the airflow direction. In this embodiment, the multiple exhaust ports 32 are located closer to one end than the third ventilation passage 102 in the direction of the central axis 49. The downstream end of the third ventilation passage 102 in the airflow direction is located at the periphery of the nearest exhaust port 32. The space between the tubular member 94 and the housing 4 where the plurality of exhaust ports 32 are arranged serves as a guide path 103 that guides air from the third ventilation path 102 to the plurality of exhaust ports 32 .

[0028] As shown in Figures 8 and 9, the first ventilation passage has an upstream first ventilation passage 82 connected to the other end of the electric suction machine cover 47 on the other end side of the electric suction machine 42, a midstream first ventilation passage 83 on the outer periphery of the upstream first ventilation passage 82, a downstream first ventilation passage 84 on the outer periphery of the midstream first ventilation passage 83, a first folding portion 86 that turns back the air flowing out from the other end opening 85 on the other end side of the upstream first ventilation passage 82 and guides it to the midstream first ventilation passage 83, and a second folding portion 87 that turns back the air flowing out from the small ventilation hole 97 on one end side of the midstream first ventilation passage 83 and guides it to the downstream first ventilation passage 84. The midstream first ventilation passage 83 is connected to the downstream end (other end opening 85) of the upstream first ventilation passage 82 in the air flow direction via the first fold portion 86, and the downstream first ventilation passage 84 is connected to the downstream end of the midstream first ventilation passage 83 in the air flow direction via the second fold portion 87.

[0029] The third sound-reducing section 81 includes a sound-reducing pipe 88 that forms the upstream first ventilation passage 82, and a sound-reducing cover 89. The sound-reducing pipe 88 has a straight pipe section 91 and a tapered section 92 whose opening widens toward the upstream side (one end) in the airflow direction. The tapered section 92 is provided on the upstream side (one end) of the sound-reducing pipe 88 in the airflow direction. The largest opening 88a of the tapered section 92 is connected to the other end of the electric suction machine cover 47, and the smallest opening of the other end of the tapered section 92 is connected to one end of the straight pipe section 91. The other end opening 85 of the straight pipe section 91 opens toward the closed end 93 in the first folded section 86. The sound-reducing cover 89 covers the outer periphery of the straight pipe section 91.

[0030] The straight pipe section 91 of the sound attenuation pipe 88 has a breathable structure on at least a portion of its peripheral surface. In the present embodiment, the breathable structure of the straight pipe section 91 is a plurality of through holes 91a that penetrate the inner and outer surfaces of the straight pipe section 91. Note that the breathable structure of the straight pipe section 91 may also be a sound-absorbing material made of a breathable material (e.g., urethane foam) that covers the inner surface of the straight pipe section 91. In this case, the straight pipe section 91 does not need to have a plurality of through holes 91a, and further, the sound attenuation cover 89 may not be provided.

[0031] As shown in Figures 8 and 9, the space between the straight pipe portion 91 and the sound-reducing cover 89 forms an expansion chamber 89a. The third sound-reducing section 81 is configured to reduce noise, including the driving noise (high-frequency noise) of the electric suction device 42 (see Figure 4), transmitted from the electric suction device 42 to the third sound-reducing section 81. The high-frequency noise of the electric suction device 42 that passes through the tapered section 92 is attenuated while reflecting off the tapered inner surface of the tapered section 92, whose cross-sectional area decreases toward the downstream side in the air flow direction. The attenuated sound waves are guided into the straight pipe portion 91 and introduced into the expansion chamber 89a through the multiple through-holes 91a of the straight pipe portion 91. A portion of the sound waves is attenuated by sound wave interference within the expansion chamber 89a. This reduces the level of noise leaking outside the housing 4. The length from one end to the other of the tapered section 92 is longer than the longitudinal length of the electric suction device 42. By increasing the length of the tapered portion 92 in this way, the angle of the taper of the tapered portion 92 can be made gentler, thereby improving the effect of attenuating high frequency sounds.

[0032] A pair of spacers 90 are provided between the outer surface (front and rear sides) of the tapered portion 92 of the third sound reduction section 81 and the inner surface (front and rear sides) of the housing 4, thereby supporting the tapered portion 92 with its axis generally aligned with the central axis 49. The entire straight tube section 91 of the third sound reduction section 81 and the other end side of the tapered portion 92 are covered by a cylindrical member 94. The cylindrical member 94 has an opening at one end connected to the outer surface of the tapered portion 92 and a closed end 93 at the other end. Furthermore, a pair of spacers 95 are provided between the outer surface (front and rear sides) of the cylindrical member 94 on the other end side of the middle in the direction of the central axis 49 and the inner surface (front and rear sides) of the housing 4, thereby supporting the cylindrical member 94 with its axis generally 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 pipe section 91 of the third sound reduction section 81 and the inner surface (front and rear sides) of the tubular member 94, thereby supporting the straight pipe section 91 with its axis roughly aligned with the central axis 49. Note that the pair of spacers 96 and the pair of spacers 95 are each small piece-shaped members, and therefore air can flow across these spacers 96, 96, 95, 95.

[0033] As shown in FIG. 9 , the first folded portion 86 is a space surrounded by the other-end opening 85 of the straight pipe portion 91 and the closed end 93 of the tubular member 94. The midstream-side first ventilation passage 83 is a space between the sound-reducing pipe 88 and the tubular member 94. A plurality of small ventilation holes 97 are provided on one end side of the tubular member 94. In this embodiment, the plurality of small ventilation holes 97 are provided on the tubular member 94 on the opposite side (front side) from the plurality of exhaust ports 32. A partition wall 98 is provided between the outer surface of the tapered portion 92 on the one end side of the tubular member 94 and the housing 4. The second folded portion 87 is a space surrounded by the one end side of the tubular member 94, the partition wall 98, and the housing 4. The downstream-side first ventilation passage 84 is a space between the tubular member 94 on the other end side of the second folded portion 87 and the housing 4.

[0034] The air that passes through the upstream first ventilation passage 82 in the third sound-reducing section 81 flows into the first fold section 86, turns around the first fold section 86 and flows into the midstream first ventilation passage 83, flows through multiple ventilation holes 97 into the second fold section 87, turns around the second fold section 87 and flows into the downstream first ventilation passage 84, and flows from the downstream first ventilation passage 84 into the second ventilation passage 101 in the handle 6.

[0035] The second ventilation passage 101 is provided inside the oval handle 6. This oval handle 6 has a distance L1 from the inner surface 101a at one end of the oval hole in the direction of the central axis 49 to the curved outer surface 101b at the other end of the oval hole, and is a portion that can be naturally gripped by a human hand. The second ventilation passage 101 inside the handle 6 is formed in a U-shape.

[0036] The upstream end 101x of the second ventilation passage 101 communicates with the other open end of the downstream first ventilation passage 84, and the downstream end 101y of the second ventilation passage 101 communicates with the other open end of the third ventilation passage 102. Thus, air from the downstream first ventilation passage 84 flows through the second ventilation passage 101 to the third ventilation passage 102. In this embodiment, a partition wall 104 is provided between the housing 4, the handle 6, and the tubular member 94 within the housing 4 to separate the first ventilation passage (the downstream first ventilation passage 84) from the third ventilation passage 102, so that air exiting the downstream end 101y of the second ventilation passage 101 does not flow back toward the downstream first ventilation passage 84 (see FIGS. 5, 6, and 9). The partition wall 104 extends from the other end face of the tubular member 94 toward one end along the left and right side surfaces. The partition wall 104 defines the downstream first ventilation passage 84 on the front side of the housing 4 and the third ventilation passage 102 on the rear side of the housing 4 .

[0037] In this vacuum cleaner, the distance of ventilation passage 41 downstream of electric suction device 42 in the airflow direction is increased to enhance noise reduction, and air is passed through not only housing 4 but also handle 6 and then discharged to the outside. Furthermore, in this embodiment, distance L3 in the direction of central axis 49 from downstream end 101y of second ventilation passage 101 to the portion of exhaust port 32 closest to the downstream end of third ventilation passage 102 in the airflow direction is equal to or greater than half of length L2 in the direction of central axis 49 of second ventilation passage 101. In other words, distance L3 is equal to or greater than (½)L2. With this configuration, air and noise that flow from inside housing 4 into handle 6 are not discharged to the outside from exhaust port 32 immediately after passing through handle 6, but are discharged to the outside from exhaust port 32 after passing through third ventilation passage 102 having distance L3. Therefore, compared to when noise that has flowed from inside the housing 4 into the handle 6 is discharged to the outside through the exhaust port 32 provided near (for example, within 5 cm) the downstream end 101y of the second ventilation passage 101, when the noise passes through the third ventilation passage 102 having the distance L3 and then is discharged to the outside through the exhaust port 32, the effect of distance attenuation of noise is obtained, which is advantageous for noise reduction. Note that, although the handle 6 is molded integrally with the housing 4 in this embodiment, the handle 6 may be a separate part from the housing 4 and may be configured to be connectable to the housing 4.

[0038] Thus, with this vacuum cleaner 1 (see FIG. 4 ), noise is reduced by the suction port body-side sound-reducing section 24, the first sound-reducing section 44, the second sound-reducing section 45, the third sound-reducing section 46, and the two folded sections (first folded section 86 and second folded section 87) between the other end opening 85 of the third sound-reducing section 46 and the exhaust port 32, as well as the second ventilation passage 101 in the handle 6, and the distance L3 of the third ventilation passage 102 is set to be equal to or greater than (½)L2, thereby forming a long exhaust path. Thus, the intake air passes through multiple sections with sound-reducing effects before being exhausted from the exhaust port 32. Therefore, compared to a vacuum cleaner without multiple sections with sound-reducing effects, including sound-reducing sections, the sound-reducing effect is improved, resulting in a vacuum cleaner with quieter operation. In this case, because the first sound-reducing section 44, dust-collecting section 43, second sound-reducing section 45, electric suction device 42, and third sound-reducing section 46 are aligned on the same central axis 49 within the housing 4, exhaust loss is kept low and suction performance is maintained. In addition, in Patent Document 1, the handle section has a third opening at a bend that bends at a substantially right angle, and airflow noise generated at the bend is released to the outside through the third opening, resulting in low noise reduction and high pressure loss. In addition, the length of the ventilation path from the electric fan to the third opening is shorter than the length of the ventilation path from the electric fan to the second opening, so the driving noise of the electric fan is released to the outside through the third opening without being sufficiently attenuated, resulting in insufficient noise attenuation over distance. The vacuum cleaner of the present embodiment can also solve the problems described in Patent Document 1.

[0039] 7 and 8 , in this embodiment, the through holes 71c of the first sound attenuation section 44 are oval, the through holes 75a of the second sound attenuation section 45 are oval, and the through holes 91a of the third sound attenuation section 81 are lattice-shaped. However, the shapes of these through holes are not particularly limited and may be elliptical, polygonal (e.g., triangular or rectangular), or irregular. Furthermore, the range in which these through holes are provided is not particularly limited. They may extend over the entire longitudinal circumference of the sound attenuation tube or less than the entire circumference, or may extend from near one end to near the other end, or from one end to the other. Furthermore, in this embodiment, these through holes penetrate the sound attenuation tube perpendicular to the central axis 49, but they may also penetrate the sound attenuation tube obliquely relative to the central axis 49.

[0040] Furthermore, the electric suction machine cover 47 is preferably attached to the sound reduction cover 74 of the second sound reduction section 45 and the tapered section 92 of the sound reduction tube 88 of the third sound reduction section 81 via an elastic member such as rubber. This reduces the transmission of vibrations from the electric suction machine 42 to the sound reduction cover 74 and the tapered section 92. Furthermore, the spacers 78, 90, 95 are preferably attached to the inner surface of the housing 4 via an elastic member such as rubber. This reduces the transmission of vibrations from the electric suction machine 42 to the housing 4.

[0041] Second Embodiment Fig. 10 is a perspective view showing a second embodiment of a vacuum cleaner 110 according to the present invention. Fig. 11 is a vertical cross-sectional view showing the vacuum cleaner 110 of the second embodiment. Fig. 12 is a vertical cross-sectional view showing the vicinity of the handle 112 of the vacuum cleaner body 111 of the second embodiment. In Figs. 10 to 12, elements that are the same as those in Figs. 1, 4, 8, and 9 are designated by the same reference numerals. The vacuum cleaner 110 of the second embodiment is configured generally similarly to the first embodiment, except that the shape of the handle 112 of the vacuum cleaner body 111 and the connection structure between the handle 112 and the housing 113 are different from those of the first embodiment. Below, differences between the second embodiment and the first embodiment will be mainly described.

[0042] The other end 113b of the housing 113 has another end surface that intersects the central axis 49 substantially perpendicularly, and an operation unit 114 is provided on the other end surface. The operation unit 114 is positioned so that the user's hand gripping the handle 112 is unlikely to accidentally come into contact with the operation unit 114. The handle 112 is ring-shaped when viewed from the left and right, and stick-shaped when viewed from the front and back. The handle 112 has a cover 112a that has the operation unit 114, and a C-shaped handle body 112b with both ends connected to the cover 112a. The operation unit 114 has multiple switches that can be used to operate the unit, such as to start / stop and switch between low and high modes.

[0043] In this embodiment, both ends of the handle body 112b are connected to the outer surface of the cover portion 112a. A partition wall 104 is provided between the housing 113, the handle 112, and the tubular member 94 within the housing 113, dividing the first ventilation passage (the downstream first ventilation passage 84) and the third ventilation passage 102. The partition wall 104 extends from the other end face of the other end of the tubular member 94 to one end along the left and right side surfaces. The partition wall 104 divides the downstream first ventilation passage 84 on the front side of the housing 4, and the third ventilation passage 102 on the rear side of the housing 4. The downstream first ventilation passage 84 is connected to the upstream end 115x of the second ventilation passage 115 in the handle body 112b through the internal space of the cover portion 112a, and the third ventilation passage 102 is connected to the downstream end 115y of the second ventilation passage 115 through the internal space of the cover portion 112a.

[0044] 12 , in the second embodiment, the annular handle 112 has a distance L1 from one end outer surface 112x to the other end outer surface 112y along the central axis 49, allowing it to be naturally gripped by a human hand. Furthermore, a distance L3 along the central axis 49 from the downstream end 115y of the second ventilation passage 115 to the portion of the exhaust port 32 closest to the downstream end of the third ventilation passage 102 in the airflow direction is equal to or greater than half the length L2 of the second ventilation passage 115 along the central axis 49. In other words, the distance L3 is equal to or greater than (½)L2. With this configuration, air and noise that flow into the handle 112 from within the housing 4 are not exhausted from the exhaust port 32 immediately after passing through the handle 112, but are exhausted from the exhaust port 32 after passing through the third ventilation passage 102 having the distance L3. Therefore, compared to when noise that flows into the handle 112 from inside the housing 4 is discharged to the outside through the exhaust port 32 located near the downstream end of the second ventilation passage 115 (for example, within 5 cm), when the noise passes through the third ventilation passage 102 having the distance L3 and then is discharged to the outside through the exhaust port 32, the noise is more effectively attenuated over distance, which is advantageous for noise reduction. Furthermore, when cleaning, this can prevent the hand holding the handle 112 from accidentally hitting the operating unit 114, causing an unintended mode change or stop. In this embodiment, the handle 112 is a separate part from the housing 4, but the handle 112 may also be molded integrally with the housing 4.

[0045] (Third Embodiment) Fig. 13 is a vertical cross-sectional view showing the suction inlet body-side sound-reducing section 24 of the suction inlet body 3 and the first sound-reducing section 118 and the second sound-reducing section 119 of the vacuum cleaner body 117 of the third embodiment. Fig. 14 is a vertical cross-sectional view showing the vicinity of the handle 6 of the vacuum cleaner body 117 of the third embodiment. In Figs. 13 and 14, elements similar to those in Figs. 7 to 9 are designated by the same reference numerals. The electric vacuum cleaner 116 of the third embodiment is generally configured similarly to the electric vacuum cleaner of the first embodiment, except that sound-absorbing materials 121, 122, 123, 124, and 125 are provided in the first sound-reducing section 118, the second sound-reducing section 119, the third sound-reducing section 120, the first folded portion 86 of the air passage 41, and the second air passage 101 in the handle 6, respectively. Differences between the third embodiment and the first embodiment will be mainly described below.

[0046] As shown in FIG. 13 , a sheet-like sound-absorbing material 121 is provided on the outer surface of the sound-attenuation tube 71 of the first sound-attenuation section 118 so as to cover the multiple through-holes 71 c. The sound-absorbing material 121 may be, for example, urethane foam. In this embodiment, the sound-absorbing material 121 covers all of the through-holes 71 c. However, the sound-absorbing material 121 may also cover only some of the through-holes 71 c, or the sound-absorbing material 121 may occupy the entire expansion chamber 71 d. By providing the sound-absorbing material 121, sound waves attempting to enter the expansion chamber 71 d are absorbed by the sound-absorbing material 121, further improving sound insulation performance (sound reduction performance). The sound-absorbing material 121 may also be provided so as to cover at least a portion of at least one of the outer and inner surfaces of the sound-attenuation tube 71.

[0047] A sheet-like sound-absorbing material 122 is provided on the outer surface of the straight pipe portion 75 of the sound-attenuation pipe 73 of the second sound-attenuation section 119 so as to cover the multiple through-holes 75a. In this embodiment, the sound-absorbing material 122 covers all of the through-holes 75a, but it may also cover some of the through-holes 75a, or the sound-absorbing material 122 may occupy the entire expansion chamber 77. By providing the sound-absorbing material 122, sound waves attempting to enter the expansion chamber 77 are absorbed by the sound-absorbing material 122, further improving sound insulation performance (sound reduction performance). Note that the sound-absorbing material 122 may be provided so as to cover at least a portion of at least one of the outer and inner surfaces of the straight pipe portion 75.

[0048] As shown in FIG. 14 , a sheet-like sound-absorbing material 123 is provided on the outer surface of the straight pipe portion 91 of the sound-attenuation pipe 88 of the third sound-attenuation section 120 so as to cover the multiple through-holes 91 a. In this embodiment, the sound-absorbing material 123 covers all of the through-holes 91 a, but it may also cover some of the through-holes 91 a, or the sound-absorbing material 123 may occupy the entire expansion chamber 89 a (see FIG. 9 ). By providing the sound-absorbing material 123, sound waves attempting to enter the expansion chamber 89 a are absorbed by the sound-absorbing material 123, further improving sound insulation performance (sound reduction performance). Note that the sound-absorbing material 123 may also be provided so as to cover at least a portion of at least one of the outer and inner surfaces of the straight pipe portion 91.

[0049] A sound-absorbing material 124 is provided inside the first folded portion 86. In this embodiment, the pad-shaped sound-absorbing material 124 is provided on the inner surface of the closed end 93 of the tubular member 94. By providing the sound-absorbing material 124, a portion of the sound waves (high frequencies) from the electric suction machine 42 (see FIG. 13 ) that have passed through the upstream first ventilation passage 82 is absorbed by the sound-absorbing material 124, further improving sound insulation performance (noise reduction performance). Note that the sound-absorbing material 124 may also be provided on the inner surface surrounding the first folded portion 86.

[0050] Sound-absorbing materials 125 are provided in the second air passage 101 inside the oval handle 6. In this embodiment, a plurality of annular sound-absorbing materials 125 are arranged on the inner surface of the handle 6 at regular intervals along the second air passage 101, thereby providing a fourth sound-reducing section 107 inside the handle 6. In the second air passage 101, the space between two adjacent sound-absorbing materials 125 forms an expansion space 126 that is wider than the inner space of each sound-absorbing material 125. In this embodiment, the fourth sound-reducing section 107 is provided with five sound-absorbing materials 125 and four expansion spaces 126 between two adjacent sound-absorbing materials 125. In the fourth sound reduction section 107, by alternately arranging multiple sound absorbing materials 125 and multiple expansion spaces 126, a portion of the sound waves (high frequency) from the electric suction device 42 (see FIG. 13 ) passing through the downstream first ventilation passage 84 is absorbed by each sound absorbing material 124. In addition, the sound waves are attenuated in each expansion space 126, further improving sound insulation performance (noise reduction performance). Note that sound absorbing materials may be provided in the first to third sound reduction sections 44, 45, and 46 of the second embodiment ( FIGS. 11 and 12 ), and a fourth sound reduction section having sound absorbing materials may be provided in the second ventilation passage 115 inside the annular handle 112. Also, some of the sound absorbing materials 121, 122, 123, 124, and 125 may be omitted. All or some of the five sound absorbing materials 125 may be omitted.

[0051] Fourth Embodiment FIG. 15 is a longitudinal cross-sectional view showing the handle and its vicinity in a vacuum cleaner body 127 of a fourth embodiment. In FIG. 15, elements similar to those in FIGS. 8 and 9 are denoted by the same reference numerals. In the fourth embodiment, the other-end opening 85 of the first ventilation passage 129 in the ventilation passage 128 communicates with the upstream end 101x of the second ventilation passage 101 via a connecting pipe 130. That is, the first folded portion 86, the midstream-side first ventilation passage 83, the second folded portion 87, and the downstream-side first ventilation passage 84 of the first embodiment are omitted. In this embodiment, the other-end opening 85 of the first ventilation passage 129 is inserted into and connected to the upstream end 130a of the connecting pipe 130, and the downstream end 130b of the connecting pipe 130 is inserted into and connected to the upstream end 101x of the second ventilation passage 101. Below, differences between the fourth embodiment and the first embodiment will be mainly described.

[0052] In the vacuum cleaner body 127 of the fourth embodiment, most of the connecting pipe 130, excluding the downstream end 130b and its vicinity, forms part of the first ventilation passage 129. The periphery of part of the connecting pipe 130 and the periphery of part of the third sound reduction section 81 form the third ventilation passage 131, and the periphery of part of the third sound reduction section 81 forms the guide passage 132. In this embodiment, the connecting pipe 130 functions as a partition wall that separates the first ventilation passage 129 and the third ventilation passage 131.

[0053] In the fourth embodiment, as in the first embodiment, the distance L3 in the direction of the central axis 49 from the downstream end 101y of the second ventilation passage 101 to the portion of the exhaust port 32 closest to the downstream end of the third ventilation passage 102 in the airflow direction is equal to or greater than (½)L2. According to the fourth embodiment, the first ventilation passage 129 can be simplified. Note that, as in the third embodiment, the fourth embodiment may also include sound-absorbing materials in the first to third sound-reducing sections 44, 45, 46, and a fourth sound-reducing section having sound-absorbing material may be provided in the second ventilation passage 101 in the handle 6 (see FIGS. 13 and 14 ).

[0054] Fifth Embodiment Fig. 16 is a vertical cross-sectional view showing the handle and its vicinity in a vacuum cleaner body 133 of a fifth embodiment. In Fig. 16, elements similar to those in Fig. 9 are given the same reference numerals. The vacuum cleaner body 133 of the fifth embodiment is generally configured similarly to the vacuum cleaner of the first embodiment, except that the handle 134 is stick-shaped and a partition wall 135 and a handle-side folded portion 136 are provided inside the handle 134. Below, differences between the fifth embodiment and the first embodiment will be mainly described.

[0055] In the fifth embodiment, a partition wall 135 is provided within the stick-shaped handle 134, dividing the interior of the handle 134 into an upstream second ventilation passage 137 on the upstream side of the airflow direction and a downstream second ventilation passage 138 on the downstream side of the airflow direction. The handle 134 also includes a handle-side folding portion 136 that folds air from the upstream second ventilation passage 137 back into the downstream second ventilation passage 138. The handle 134 has a straight portion 139 and a tapered portion 140 provided at one end of the straight portion 139. The outer surface 134a at the other end of the straight portion 139 is hemispherical. The diameter of the tapered portion 140 increases from the other end to the one end, and the other end of the tapered portion 140 is connected to the one end of the straight portion 139, and the one end of the tapered portion 140 is connected to the other end of the housing 4.

[0056] In this embodiment, the stick-shaped handle 134 is a portion having a length L1 from the other end outer surface 134a to one end 134b, which has the largest outer diameter, of the tapered portion 140. The other end of the partition wall 104 in the housing 4 is connected to one end of a partition wall 135 in the handle 134, the downstream end of the downstream-side first ventilation passage 84 communicates with the upstream end 137a of the upstream-side second ventilation passage 137, and the downstream end 138a of the downstream-side second ventilation passage 138 communicates with the upstream end of the third ventilation passage 102. The length L2 in the direction of the central axis 49 of the second ventilation passage is the combined length of the upstream-side second ventilation passage 137 or the downstream-side second ventilation passage 138 and the handle-side folded portion 136. The distance L3 in the direction of the central axis 49 from the downstream end 138a of the downstream second ventilation passage 138 to the part of the exhaust port 32 that is closest to the downstream end of the third ventilation passage 102 in the airflow direction is equal to or greater than (½)L2. As in the third embodiment, the fifth embodiment may also have sound-absorbing materials provided in the first to third sound-reducing sections 44, 45, 46, and a fourth sound-reducing section having sound-absorbing materials provided in the upstream second ventilation passage 137 and the downstream second ventilation passage 138 in the handle 134 (see FIGS. 13 and 14 ).

[0057] Sixth Embodiment Fig. 17 is a vertical cross-sectional view showing the handle and its vicinity in a vacuum cleaner body 141 of a sixth embodiment. In Fig. 17, elements similar to those in Figs. 15 and 16 are assigned the same reference numerals. The vacuum cleaner body 141 of the sixth embodiment is generally configured similarly to the vacuum cleaner of the first embodiment, except that the first folded portion 86, the midstream-side first ventilation passage 83, the second folded portion 87, and the downstream-side first ventilation passage 84 in the ventilation passage 41 of the first embodiment are omitted (see Figs. 8 and 9), and the handle 134 has a stick-like shape. Below, differences between the sixth embodiment and the first embodiment will be mainly described.

[0058] In the sixth embodiment, the oval handle 6 of the fourth embodiment (see FIG. 15 ) is modified to a stick-like shape. The stick-like handle 134 has a straight portion 139 and a tapered portion 140, as in the fifth embodiment. The handle 134 also includes a partition wall 135 that divides the second ventilation passage into an upstream second ventilation passage 137 on the upstream side in the airflow direction and a downstream second ventilation passage 138 on the downstream side in the airflow direction, and a handle-side folding portion 136 that folds air from the upstream second ventilation passage 137 back into the downstream second ventilation passage 138. In this case, one end of the partition wall 135 is located near the other end of the tapered portion 140.

[0059] The other end opening 85 of the first ventilation passage 129 and the upstream end 137a of the upstream second ventilation passage 137 are in communication with each other via a connecting pipe 130. In this embodiment, the other end opening 85 of the first ventilation passage 129 is inserted into and connected to the upstream end 130a of the connecting pipe 130, and the downstream end 130b of the connecting pipe 130 is inserted into and connected to the upstream end 137a of the upstream second ventilation passage 137 between the partition wall 135 at the back and the handle 134.

[0060] In the vacuum cleaner body 141 of the sixth embodiment, the connecting pipe 130 forms a part of the first ventilation passage 129 and a part of the upstream second ventilation passage 137. The periphery of a part of the connecting pipe 130 and the periphery of a part of the third sound reduction section 81 form the third ventilation passage 131, and the periphery of a part of the third sound reduction section 81 forms the guide passage 132. In the case of the present embodiment, the connecting pipe 130 functions as a partition wall separating the first ventilation passage 129 and the third ventilation passage 131, and also functions as a partition wall separating the upstream second ventilation passage 137 and the downstream second ventilation passage 138.

[0061] In the sixth embodiment, as in the first embodiment, the distance L3 in the direction of the central axis 49 from the downstream end 138a of the downstream-side second ventilation passage 138 to the portion of the exhaust port 32 closest to the downstream end of the third ventilation passage 131 in the airflow direction is equal to or greater than (½)L2. According to the sixth embodiment, the first ventilation passage 129 can be simplified. Note that, as in the third embodiment, the sixth embodiment may also include sound-absorbing materials in the first to third sound-reducing sections 44, 45, and 46, and a fourth sound-reducing section having sound-absorbing materials may be provided in the upstream-side second ventilation passage 137 and the downstream-side second ventilation passage 138 in the handle 134 (see FIGS. 13 and 14 ).

[0062] Other Embodiments 1. In the third embodiment, the first to fourth sound reduction units 44, 45, 46, and 107 are provided (see FIGS. 13 and 14 ). However, at least the fourth sound reduction unit 107 may be provided among the first to fourth sound reduction units 44, 45, 46, and 107. This also applies to the first, second, and fourth to sixth embodiments. 2. In the first embodiment, the multiple exhaust ports 32 of the vacuum cleaner body 2 are provided on the other end side of the electric suction unit 42 (see FIG. 4 ). However, the multiple exhaust ports 32 may be provided on one end side of the electric suction unit 42. For example, the multiple exhaust ports 32 may be provided in the housing 4 surrounding the second sound reduction unit 45, the housing 4 surrounding the dust collection unit 43, or the housing 4 surrounding the first sound reduction unit 44. This also applies to the second to sixth embodiments. 3. In the fifth and sixth embodiments, the handle 134 is shaped like a straight stick (see FIGS. 16 and 17), but the handle may be shaped like a rod with a bent portion. 4. In the first embodiment, the handle 6 extends parallel to the central axis 49 (see FIG. 4), but the handle 6 may be inclined (bent) backward relative to the central axis 49.

[0063] Preferred aspects of the present invention include any combination of the above-described aspects. In addition to the above-described embodiments, various modifications of the present invention are possible. These modifications should not be interpreted as not falling within the scope of the present invention. The present invention should include all modifications within the meaning and scope of the claims.

Claims

1. A vacuum cleaner comprising: a housing having an air intake and an exhaust port; a handle provided on the housing; a ventilation passage for directing air from the air intake to the exhaust port; and an electric suction device provided in the ventilation passage; the ventilation passage downstream of the electric blower in the airflow direction has a first ventilation passage provided within the housing, a second ventilation passage provided in the handle and communicating with the downstream end of the first ventilation passage in the airflow direction, and a third ventilation passage provided within the housing and communicating with the downstream end of the second ventilation passage in the airflow direction; the air intake is located at one end side of the housing in the direction of the central axis; the exhaust port is located at the other end side of the air intake in the direction of the central axis and at the one end side of the third ventilation passage; the handle is located on the other end side of the housing; and the distance in the direction of the central axis from the downstream end of the second ventilation passage to the part of the exhaust port closest to the downstream end of the third ventilation passage in the airflow direction is equal to or greater than half the length in the direction of the central axis of the second ventilation passage.

2. The vacuum cleaner according to claim 1, wherein a partition wall is provided within the housing to separate the first ventilation passage and the third ventilation passage.

3. The vacuum cleaner according to claim 2, wherein the handle is a ring-shaped or stick-shaped handle.

4. An electric vacuum cleaner as described in claim 3, wherein the inside of the stick-shaped handle is provided with a partition wall that divides the second ventilation passage into an upstream second ventilation passage on the upstream side in the air flow direction and a downstream second ventilation passage on the downstream side in the air flow direction, and a handle-side folding portion that folds back air from the upstream second ventilation passage into the downstream second ventilation passage.

5. The electric vacuum cleaner according to claim 4, wherein the first ventilation passage has an upstream first ventilation passage connected to the other end side of the electric suction machine, a midstream first ventilation passage on the outer periphery of the upstream first ventilation passage, a downstream first ventilation passage on the outer periphery of the midstream first ventilation passage, a first turning portion which turns back air flowing out from the other end opening on the other end side of the upstream first ventilation passage and guides it to the midstream first ventilation passage, and a second turning portion which turns back air flowing out from the one end opening on one end side of the midstream first ventilation passage and guides it to the downstream first ventilation passage, and the other end opening on the other end side of the downstream first ventilation passage is connected to the second ventilation passage.

6. The vacuum cleaner according to any one of claims 1 to 5, further comprising a sound reduction section that forms part of the ventilation passage and reduces noise including airflow noise.

7. The vacuum cleaner according to claim 6, wherein the sound reduction section has a sound reduction tube having a ventilated structure on at least a portion of its surrounding surface.

8. The vacuum cleaner according to claim 7, wherein the breathable structure is a plurality of through holes penetrating the inner and outer surfaces of the sound-reducing tube.

9. The vacuum cleaner according to claim 7, wherein the sound reduction section further comprises a sound absorbing material covering at least a portion of at least one of an outer surface and an inner surface of the sound reduction tube.

10. The vacuum cleaner according to claim 7, wherein the sound reduction section further has a sound reduction cover that covers the outer periphery of the sound reduction tube.

11. The vacuum cleaner according to any one of claims 1 to 5, wherein the exhaust port is provided at a position on the housing at one end or the other end side of the electric suction machine so as not to face the electric suction machine.

12. An electric vacuum cleaner as claimed in claim 1 or 2, wherein the inside of the handle is provided with a partition wall that divides the second ventilation passage into an upstream second ventilation passage on the upstream side in the air flow direction and a downstream second ventilation passage on the downstream side in the air flow direction, and a handle side folding portion that folds back air from the upstream second ventilation passage into the downstream second ventilation passage.

13. An electric vacuum cleaner as claimed in any one of claims 1 to 3, wherein the first ventilation passage has an upstream first ventilation passage connected to the other end side of the electric suction machine, a midstream first ventilation passage on the outer periphery of the upstream first ventilation passage, a downstream first ventilation passage on the outer periphery of the midstream first ventilation passage, a first turning portion which turns back air flowing out from the other end opening on the other end side of the upstream first ventilation passage and guides it to the midstream first ventilation passage, and a second turning portion which turns back air flowing out from the one end opening on one end side of the midstream first ventilation passage and guides it to the downstream first ventilation passage, and the other end opening on the other end side of the downstream first ventilation passage is connected to the second ventilation passage.

14. An electric vacuum cleaner comprising a housing having an air intake and an exhaust port, a hollow handle connected to the housing, a ventilation passage through which air from the air intake port flows to the exhaust port, an electric suction machine provided in the ventilation passage, a dust collection unit provided in the ventilation passage upstream of the electric suction machine in the airflow direction, and a sound-reducing unit that forms part of the ventilation passage and reduces noise including airflow noise, wherein the inside of the handle forms part of the ventilation passage, and the sound-reducing unit includes at least a fourth sound-reducing unit out of a first sound-reducing unit that forms part of the ventilation passage upstream of the dust collection unit in the airflow direction and reduces noise including airflow noise, a second sound-reducing unit that forms part of the ventilation passage between the dust collection unit and the electric suction machine and reduces noise including the operation of the electric suction machine, a third sound-reducing unit that forms part of the ventilation passage downstream of the electric suction machine in the airflow direction and reduces noise including the operation of the electric suction machine, and a fourth sound-reducing unit that forms part of the ventilation passage in the handle and reduces noise including airflow noise.

15. The vacuum cleaner according to claim 14, further comprising an attachment that is detachable from an air inlet of the vacuum cleaner body.

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