Electric vacuum cleaner

Abstract

This electric vacuum cleaner comprises a housing which has an intake port and an exhaust port, a ventilation passage through which air from the intake port flows to the exhaust port, an electric suction machine which is provided in the ventilation passage, a dust collecting portion which is provided in the ventilation passage upstream of the electric suction machine in the airflow direction, and a sound reducing portion which forms a portion of the ventilation passage upstream of the dust collecting portion in the airflow direction, and which reduces noise including an airflow sound, wherein the sound reducing portion is disposed within the housing.

Description

vacuum cleaner

[0001] This application claims priority to Japanese Patent Application No. 2023-169851, filed on September 29, 2023, the contents of which are incorporated herein by reference.

[0002] As a conventional electric vacuum cleaner, Patent Document 1 discloses a canister-type electric vacuum cleaner in which a partition wall with a communication port is provided between a dust collection chamber and an electric blower inside the vacuum cleaner body, a vibration plate is provided on the upstream side of the partition wall in the airflow direction, and a sound-absorbing material is disposed in a hole-like space provided in the vibration plate. According to this electric vacuum cleaner, when the electric blower is operated, high-frequency sound is generated from the electric blower, and the high-frequency sound is radiated toward the dust collection chamber through the communication port in front of the electric blower, and the high-frequency sound that passes through the vibration plate is absorbed by the sound-absorbing material, thereby reducing noise.

[0003] JP 2012-5561 A

[0004] In the case of the vacuum cleaner of Patent Document 1, the sound-absorbing member between the dust collection chamber and the electric blower obstructs the flow of air, making it easy for suction performance to decrease, so there is a demand for a vacuum cleaner that can reduce noise while preventing a decrease in suction performance.

[0005] 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.

[0006] The present invention provides an electric vacuum cleaner comprising a housing having an air intake port and an exhaust port, a ventilation duct for directing air from the air intake port to the exhaust port, an electric suction device provided in the ventilation duct, a dust collection unit provided in the ventilation duct upstream of the electric suction device in the airflow direction, and a sound reduction unit that forms part of the ventilation duct upstream of the dust collection unit in the airflow direction and reduces noise including airflow sound, the sound reduction unit being located within the housing.

[0007] The present invention also provides an electric vacuum cleaner comprising: a housing having an air intake port and an exhaust port; a ventilation passage for directing air from the air intake port to the exhaust port; an electric suction machine provided in the ventilation passage; and a dust collection section provided in the ventilation passage upstream of the electric suction machine in the airflow direction; the air intake port is provided at one end of the housing in the direction of the central axis; the exhaust port is provided at the other end of the housing in the direction of the central axis; and the ventilation passage has a first ventilation passage connected to the other end of the electric suction machine, a second ventilation passage on the outer periphery of the first ventilation passage, a third ventilation passage on the outer periphery of the second ventilation passage, a first folding section that turns back air flowing out from an opening on the other end of the first ventilation passage and guides it to the second ventilation passage, and a second folding section that turns back air flowing out from an opening on one end of the second ventilation passage and guides it to the third ventilation passage.

[0008] The present invention also provides an electric vacuum cleaner having a vacuum cleaner body that includes: a housing having an air intake port and an exhaust port; a ventilation passage that flows air from the air intake port to the exhaust port; an electric suction device provided in the ventilation passage; a dust collection unit provided in the ventilation passage upstream of the electric suction device in the airflow direction; a first sound reduction unit that forms part of the ventilation passage upstream of the dust collection unit in the airflow direction and reduces noise including airflow sound; a second sound reduction unit that forms part of the ventilation passage between the dust collection unit and the electric suction device and reduces noise including driving noise of the electric suction device; and a third sound reduction unit that forms part of the ventilation passage downstream of the electric suction device in the airflow direction and reduces noise including driving noise of the electric suction device.

[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 cross-sectional view showing a suction mouth body of the vacuum cleaner of the first embodiment; FIG. 3 is a longitudinal cross-sectional view showing the vacuum cleaner of the first embodiment; FIG. 4 is a longitudinal cross-sectional view showing the vicinity of the handle of the vacuum cleaner of the first embodiment; FIG. 5 is a perspective view showing a vacuum cleaner body of the first embodiment; FIG. 6 is a longitudinal cross-sectional view showing a first sound reduction section and a second sound reduction section of the vacuum cleaner body of the first embodiment; FIG. 7 is a longitudinal cross-sectional view showing a third sound reduction section of the vacuum cleaner body of the first embodiment; FIG. 8 is a longitudinal cross-sectional view showing the first sound reduction section and the second sound reduction section of the vacuum cleaner body of the second embodiment; FIG. 9 is a longitudinal cross-sectional view showing the third sound reduction section of the vacuum cleaner body of the second embodiment;

[0011] The present invention will be described in more detail below with reference to the accompanying drawings. Note that the following description is illustrative 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 10 provided on an upper end 9b of the 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 10 is positioned at the rearmost position, and the vacuum cleaner main body 2 is tilted backward from the lower end 9a to the upper end 9b. In the following description, the lower end 9a of the vacuum cleaner main body 2 shown in Fig. 1 may be referred to as one end 9a, and the upper end 9b may be referred to as the other end 9b.

[0013] The housing 4 of the vacuum cleaner main body 2 has a cylindrical body 5, a battery mounting section 6 provided on the outer surface of one end 9a of the body 5, and a circuit board storage section 7 provided on the outer surface of the other end 9b of the body 5. When using the vacuum cleaner 1 for cleaning, the battery mounting section 6 is located on the rear surface of the one end 9a of the body 5, and the circuit board storage section 7 is located on the rear surface of the other end 9b of the body 5. A battery 8 is detachably mounted in the battery mounting section 6. A circuit board 34 (see FIG. 3 ) serving as a control unit is housed inside the circuit board storage section 7. In this embodiment, the body 5 of the housing 4 is generally cylindrical, but is not limited to a cylindrical shape and may be partially or entirely rectangular, or may be a cylindrical shape with a polygonal cross section.

[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 longitudinal cross-sectional view showing the vacuum cleaner 1 of the first embodiment. FIG. 4 is a longitudinal cross-sectional view showing the handle and its vicinity in the vacuum cleaner of the first embodiment. The other end 9b of the body 5 of the housing 4 has an end surface 9c that intersects approximately perpendicularly with the central axis 32 of the body 5, and an operating unit 311 is provided on the other end surface 9c. The handle 10 has a cover 10a fitted to the other end 9b of the body 5 of the housing 4 so as to cover the operating unit 311, and a C-shaped handle body 10b with both ends connected to the cover 10a. The cover 10a has a membrane 10c that intersects approximately perpendicularly with the central axis 32 between both ends of the handle body 10b. The membrane 10c forms part of the inner periphery of the handle body 10b. Text such as "ON / OFF" and "LOW / HIGH" is printed on the outer surface of the membrane 10c at the position of each switch of the operating unit 311. Furthermore, if the operation unit 311 is provided with an indicator light (for example, an LED), at least a portion of the film portion 10c may be translucent so as to transmit the light of the indicator light.

[0016] Handle body 10b is provided at the other end 9b of housing 4 so that it appears to be a stick extending on central axis 32 when viewed from the front-to-back direction, but appears to be a substantially circular ring when viewed from the left-to-right direction. Therefore, when a user reaches out from the rear of vacuum cleaner 1, they can naturally grasp handle body 10b (without twisting their wrist). In this embodiment, handle 10 is substantially circular, but the shape of handle 10 may also be a substantially oval or elliptical ring, or a substantially polygonal ring.

[0017] The operation unit 311 has multiple push-button switches (not shown), and the user can adjust the output of the electric vacuum cleaner 36 (switching between on and off, switching between weak and strong modes, etc.) by pressing the switches via the membrane portion 10c of the handle 10. Because the handle 10 is annular, the user can smoothly move their hand to a position on the handle 10 that is easy to grip, depending on the tilt angle α of the vacuum cleaner 1 relative to the floor surface F. Furthermore, because the operation unit 311 is located in a non-graspable portion of the handle 10 (membrane portion 10c), it is possible to prevent the user from accidentally touching the switch on the operation unit 311 while gripping the handle 10 and unintentionally changing the mode or stopping the vacuum cleaner. Furthermore, because the heavy battery 8 is attached to the battery attachment portion 6 at the lower end 9a (one end 9a) of the vacuum cleaner body 2, the center of gravity of the vacuum cleaner 1 is lowered, making it easier to handle. In this embodiment, the battery 8 is heavier than the electric vacuum cleaner 36, and therefore the vacuum cleaner 1 is designed to be easily lowered in center of gravity.

[0018] The housing 4 of the vacuum cleaner body 2 has an air intake 33 on an end surface on one end 9a of the body 5. The connecting pipe 23 (see FIG. 2) of the suction port body 3 is removably inserted into the air intake 33 of the vacuum cleaner body 2. Returning to FIG. 1 , the housing 4 has a plurality of small hole-like exhaust ports 11 on the peripheral surface on the other end 9b of the body 5. In the present embodiment, the plurality of exhaust ports 11 are located on the front surface of the body 5 when cleaning with the vacuum cleaner 1. The plurality of exhaust ports 11 may be provided on at least one of the left and right side surfaces on the other end 9b of the body 5, or on at least one of the left and right side surfaces and the rear surface of the circuit board storage section 7. Furthermore, in this embodiment, the plurality of exhaust ports 11 are of three different sizes: large, medium, and small, and are arranged in order from the other end 9b to the other end 9b as groups of large size exhaust ports 11 (e.g., diameter 1.5 to 2.0 mm), medium size exhaust ports 11 (e.g., diameter 1.0 to 1.5 mm), and small size exhaust ports 11 (e.g., diameter 0.5 to 1.0 mm) (see FIG. 1). Note that the plurality of exhaust ports 11 may be of the same size.

[0019] FIG. 5 is a perspective view showing the vacuum cleaner body 2 of the electric vacuum cleaner 1 of the first embodiment. FIG. 5 shows the vacuum cleaner body 2 with the suction port body 3 detached from the air inlet 33 and the battery 8 (see FIG. 1 ) detached from the battery mounting portion 6. In this embodiment, the vacuum cleaner 1 may be equipped with attachments other than the suction port body. Examples of such attachments include a crevice nozzle, a brush nozzle, and a hose nozzle. Therefore, attachments other than the suction port body can be attached and detached to the air inlet 33 of the vacuum cleaner body 2. For example, when connecting a crevice nozzle to the vacuum cleaner body 2 to clean a corner of a room, the user can hold the handle 10 with one hand and support the rear surface of the body 5 of the housing 4 (e.g., near the battery 8) with the other hand, making it easier to move the crevice nozzle to the desired position. Even in this case, the center of gravity is lowered by the battery 8 located near the air inlet 33, making the vacuum cleaner body 2 easier to handle.

[0020] 3 , the housing 4 is provided with an air passage 35 through which air from the air intake 33 flows to the exhaust port 11, an electric suction device 36 provided in the air passage 35, a dust collection unit 37 provided in the air passage 35 upstream of the electric suction device 36 in the airflow direction, a first sound reduction unit 38 provided in the air passage 35 between the air intake 33 and the dust collection unit 37, a second sound reduction unit 39 provided in the air passage 35 between the dust collection unit 37 and the electric suction device 36, and a third sound reduction unit 310 provided in the air passage 35 between the electric suction device 36 and the exhaust port 11. The first sound reduction unit 38 is disposed in the housing 4 and forms a part of the air passage upstream of the dust collection unit 37 in the airflow direction. The second sound reduction unit 39 is disposed in the housing 4 and forms a part of the air passage 35 between the dust collection unit 37 and the electric suction device 36. The third sound reduction section 310 is disposed inside the housing 4 and forms part of the ventilation passage 35 downstream of the electric suction device 36 in the airflow direction.

[0021] FIG. 6 is a longitudinal cross-sectional view showing the first and second sound-reducing sections 38 and 39 of the vacuum cleaner body of the first embodiment. The first sound-reducing section 38 includes a sound-reducing tube 51 and a sound-reducing cover 52 that covers the outer periphery of the sound-reducing tube 51. While the sound-reducing cover 52 partially covers the outer periphery of the sound-reducing tube 51 in FIG. 6, it may cover the entire outer periphery of the sound-reducing tube 51. The sound-reducing tube 51 has a first end opening 51a connected to the air intake 33 and a second end opening 51b connected to the inlet 37a at one end of the dust collection section 37. As shown in FIG. 5, the battery 8 attached to the battery attachment section 6 is arranged on the outer surface of the housing 4 near the first sound-reducing section 38, substantially parallel to the sound-reducing tube 51 of the first sound-reducing section 38. The sound-reducing tube 51 has a ventilated structure on at least a portion of its periphery. In the present embodiment, the breathable structure of the sound attenuation tube 51 is a plurality of through holes 51c that penetrate the inner and outer surfaces of the sound attenuation tube 51. Note that the breathable structure of the sound attenuation tube 51 may also be a sound-absorbing material made of a breathable material (for example, urethane foam) that covers the inner surface of the sound attenuation tube 51, in which case the sound attenuation tube 51 does not need to have a plurality of through holes 51c, and further the sound attenuation cover 52 may not be required.

[0022] The space between the sound-reducing tube 51 and the sound-reducing cover 52 forms an expansion chamber 51d. The first sound-reducing section 38 is configured to reduce noise, including ventilation noise from air flowing from the air intake 33 to the first sound-reducing section 38. Noise from the air intake 33 is transmitted inside the sound-reducing tube 51 of the first sound-reducing section 38. The noise (sound waves) is introduced into the expansion chamber 51d through multiple through-holes 51c of the sound-reducing tube 51, and a portion of the noise is reduced by sound wave interference within the expansion chamber 51d. This reduces the level of noise leaking outside the housing 4. Because the first sound-reducing section 38 is provided in the ventilation passage 35 near the air intake 33 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.

[0023] 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.

[0024] Returning to FIG. 6 , the dust collection unit 37 has an inlet 37a at one end through which dust-laden air flows in from the air intake 33 and an outlet 37b at the other end through which dust-free air is discharged to the second sound reduction unit 39. A dust collection bag or a dust collection device is housed in the internal space of the dust collection unit 37. 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, a cyclone unit including a centrifugal separator (inner cylinder) and a container body can be provided, 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.

[0025] An openable lid (not shown) constituting part of the housing 4 is provided near the dust collection unit 37. The lid can be opened to remove a dust collection bag or dust collection device (dust collection container) from the dust collection unit 37 and dispose of the dust. The lid has a double structure in which part of the outer wall (housing 4) is integrated with part of the wall forming the dust collection unit 37. 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) more than a cyclone-type dust collection device.

[0026] The second sound reduction section 39 includes a sound reduction tube 53 and a sound reduction cover 54. The sound reduction tube 53 has a first end opening 39a connected to the discharge port 37b of the dust collection section 37 and a second end opening 39b connected to the suction port 36a of the electric suction machine 36. The sound reduction cover 54 only needs to cover at least a portion of the outer periphery of the sound reduction tube 53; in this embodiment, the sound reduction cover 54 covers the entire outer periphery of the sound reduction tube 53. The sound reduction tube 53 has a straight tube section 53a and a tapered section 53b whose opening widens toward the upstream side (one end) in the airflow direction. The tapered section 53b is located on the upstream side (one end) of the sound reduction tube 53 in the airflow direction. The first end opening 39a, which is the largest opening of the tapered section 53b, connects to the other end of the peripheral wall that forms the dust collection section 37, and the other end, which is the smallest opening of the tapered section 53b, connects to one end of the straight tube section 53a. One end of the sound-reducing cover 54 is connected to the outer surface of the tapered portion 53 b near one end opening 39 a , and the other end of the sound-reducing cover 54 is connected to one end of an electric suction machine cover 55 that covers the electric suction machine 36 .

[0027] The straight pipe section 53a of the sound attenuation pipe 53 has a breathable structure on at least a portion of its peripheral surface. In this embodiment, the breathable structure of the straight pipe section 53a is a plurality of through holes 53c that penetrate the inner and outer surfaces of the straight pipe section 53a. Note that the breathable structure of the straight pipe section 53a 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 53a. In this case, the straight pipe section 53a does not need to have a plurality of through holes 53c, and further, the sound attenuation cover 54 may not be required.

[0028] The space between the sound attenuation tube 53 and the sound attenuation cover 54 forms an expansion chamber 53d. The second sound attenuation section 39 is configured to reduce noise, including ventilation noise from air flowing from the dust collection section 37 to the second sound attenuation section 39 and the driving noise (high-frequency noise) of the electric suction machine 36 transmitted from the electric suction machine 36 to the second sound attenuation section 39. Noise (sound waves) transmitted inside the sound attenuation tube 53 of the second sound attenuation section 39 are introduced into the expansion chamber 53d through the multiple through-holes 53c of the straight pipe section 53a, and are partially attenuated by sound wave interference within the expansion chamber 53d. This reduces the level of noise leaking outside the housing 4. In addition, a pair of spacers 57 are provided between the outer surface (front and rear sides) of the sound-reducing cover 54 at the middle in the direction of the central axis 32 and the inner surface (front and rear sides) of the body 5 of the housing 4, thereby supporting the sound-reducing cover 54 with the axis of the second sound-reducing section 39 roughly aligned with the central axis 32.

[0029] 7 is a vertical cross-sectional view showing the third sound reduction section 310 of the vacuum cleaner body of the first embodiment. The ventilation passage 35 downstream of the electric suction device 36 in the airflow direction includes a first ventilation passage 61 connected to the other end of the electric suction device cover 55 located on the other end side of the electric suction device 36, a second ventilation passage 63 located outside the periphery of the first ventilation passage 61, a third ventilation passage 65 located outside the periphery of the second ventilation passage 63, a first folding portion 62 that turns back the air flowing out from the other end opening on the other end side of the first ventilation passage 61 and guides it to the second ventilation passage 63, and a second folding portion 64 that turns back the air flowing out from the one end opening on one end side of the second ventilation passage 63 and guides it to the third ventilation passage 65.

[0030] The third sound-reducing section 310 includes a sound-reducing pipe 66 that forms the first ventilation passage 61 and a sound-reducing cover 67. The sound-reducing pipe 66 has a straight pipe section 68 and a tapered section 69 whose opening widens toward the upstream side (one end) in the airflow direction. The tapered section 69 is located on the upstream side (one end) of the sound-reducing pipe 66 in the airflow direction. The largest opening 66a of the tapered section 69 is connected to the other end of the electric suction machine cover 55, and the smallest opening of the tapered section 69 is connected to one end of the straight pipe section 68. The other end opening 66b of the straight pipe section 68 opens toward the closed end 613 in the first folded section 62. The sound-reducing cover 67 covers the outside periphery of the straight pipe section 68.

[0031] The straight pipe section 68 of the sound attenuation pipe 66 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 68 is a plurality of through holes 610 that penetrate the inner and outer surfaces of the straight pipe section 68. Note that the breathable structure of the straight pipe section 68 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 68. In this case, the straight pipe section 68 does not need to have a plurality of through holes 610, and further, the sound attenuation cover 67 may not be required.

[0032] The space between the straight pipe portion 68 and the sound-reducing cover 67 forms an expansion chamber 611. The third sound-reducing section 310 is configured to reduce noise, including the driving noise (high-frequency noise) of the electric suction device 36, transmitted from the electric suction device 36 to the third sound-reducing section 310. The high-frequency noise of the electric suction device 36 that passes through the tapered section 69 is attenuated while reflecting off the tapered inner surface of the tapered section 69, 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 68 and introduced into the expansion chamber 611 through the multiple through-holes 53c of the straight pipe portion 53a. A portion of the sound waves is attenuated by sound wave interference within the expansion chamber 611. This reduces the level of noise leaking outside the housing 4. The length from one end to the other of the tapered section 69 is longer than the longitudinal length of the electric suction device 36 (see FIG. 3). By increasing the length of the tapered portion 69 in this way, the angle of the taper of the tapered portion 69 can be made gentler, thereby improving the effect of attenuating high frequency sounds.

[0033] A pair of spacers 71 are provided between the outer surface (front and rear sides) of the tapered portion 69 of the third sound reduction section 310 and the inner surface (front and rear sides) of the body 5 of the housing 4, thereby supporting the tapered portion 69 with its axis generally aligned with the central axis 32. The entire straight pipe section 68 of the third sound reduction section 310 and the other end side of the tapered portion 69 are covered by a cylindrical member 612. The cylindrical member 612 has an opening at one end connected to the outer surface of the tapered portion 69 and a closed end 613 at the other end. Furthermore, a pair of spacers 72 are provided between the outer surface (front and rear sides) of the cylindrical member 612 on the other end side of the middle in the direction of the central axis 32 and the inner surface (front and rear sides) of the body 5 of the housing 4, thereby supporting the cylindrical member 612 with its axis generally aligned with the central axis 32. Furthermore, a pair of spacers 73 are provided between the outer surface (front and rear sides) of the other end of the straight pipe section 68 of the third sound reduction section 310 and the inner surface (front and rear sides) of the tubular member 612, thereby supporting the straight pipe section 68 with its axis generally aligned with the central axis 32. Note that the pair of spacers 72 and the pair of spacers 73 are each small piece-shaped members, and therefore air can flow across these spacers 72, 72, 73, 73.

[0034] The first folded portion 62 is a space surrounded by the other end opening 66b of the straight pipe portion 68 and the closed end 613 of the tubular member 612. The second ventilation passage 63 is a space between the sound-reducing pipe 66 and the tubular member 612. A plurality of small ventilation holes 614 are provided on one end of the tubular member 612. In this embodiment, the plurality of small ventilation holes 614 are provided on the same side (front side) of the tubular member 612 as the plurality of exhaust ports 11, but they may be provided around the entire circumference of the tubular member 612. A partition wall 615 is provided between the outer surface of the tapered portion 69 on the one end side of the tubular member 612 and the housing 4. The second folded portion 64 is a space surrounded by the one end side of the tubular member 612, the partition wall 615, and the housing 4. The third ventilation passage 65 is a space between the tubular member 612 on the other end side of the second folded portion 64 and the housing 4. A plurality of small exhaust ports 11 are arranged near the middle between one end and the other end of the third ventilation passage 65, and the size of the exhaust ports 11 increases stepwise from the middle to the other end of the third ventilation passage 65.

[0035] Air that passes through the first ventilation passage 61 in the third sound reduction section 310 flows into the first folded section 62, turns around the first folded section 62, flows into the second ventilation passage 63, passes through the plurality of small ventilation holes 614, flows into the second folded section 64, turns around the second folded section 64, flows into the third ventilation passage 65, and is discharged from the third ventilation passage 65 to the outside through the plurality of exhaust ports 11. At this time, the size of the plurality of exhaust ports 11 increases toward the other end, so that air can be discharged to the outside generally uniformly from the exhaust ports 11 at one end of the third ventilation passage 65 to the exhaust ports 11 at the other end.

[0036] As described above, with this electric vacuum cleaner 1 (see FIG. 3 ), the intake air is exhausted from the exhaust port 11 through multiple sound-reducing sections, including the suction port body-side sound-reducing section 24, the first sound-reducing section 38, the second sound-reducing section 39, the third sound-reducing section 310, and the two folded sections (first folded section 62 and second folded section 64) between the other end opening 66 b of the third sound-reducing section 310 and the exhaust port 11, which form a long exhaust path. Therefore, compared to a vacuum cleaner that does not have multiple sound-reducing sections, including sound-reducing sections, the sound-reducing effect is improved, resulting in a vacuum cleaner with quieter operation. Since the first sound-reducing section 38, dust collecting section 37, second sound-reducing section 39, electric suction motor 36, and third sound-reducing section 310 are aligned on the same central axis 32 within the housing 4, exhaust loss is kept low and suction performance is maintained.

[0037] As shown in Figures 6 and 7, in this embodiment, the through holes 51c of the first sound attenuation section 38 are oval, the through holes 53c of the second sound attenuation section 39 are oval, and the through holes 610 of the third sound attenuation section 310 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 and 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 of the sound attenuation tube 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 32, but the through holes may also penetrate the sound attenuation tube obliquely relative to the central axis 32.

[0038] Furthermore, the electric suction machine cover 55 is preferably attached to the sound reduction cover 54 of the second sound reduction section 39 and the tapered section 69 of the sound reduction tube 66 of the third sound reduction section 310 via an elastic member such as rubber. This reduces the transmission of vibrations from the electric suction machine 36 to the sound reduction cover 54 and the tapered section 69. Furthermore, the spacers 71, 72, and 73 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 36 to the housing 4.

[0039] Second Embodiment Fig. 8 is a longitudinal cross-sectional view showing the first and second sound reduction sections of the vacuum cleaner body of the second embodiment. Fig. 9 is a longitudinal cross-sectional view showing the third sound reduction section of the vacuum cleaner body of the second embodiment. In Figs. 8 and 9, elements that are the same as those in Figs. 6 and 7 are given the same reference numerals. The vacuum cleaner of the second embodiment is configured similarly to the vacuum cleaner of the first embodiment, except that sound absorbing materials 81, 82, 91, and 92 are provided in the first sound reduction section 38, the second sound reduction section 39, the third sound reduction section 310, and the first folded portion 62 of the ventilation passage 35, respectively. Below, differences between the second embodiment and the first embodiment will be mainly described.

[0040] As shown in FIG. 8 , a sheet-like sound-absorbing material 81 is provided on the outer surface of the sound-attenuation tube 51 of the first sound-attenuation section 38 so as to cover the multiple through-holes 51 c. The sound-absorbing material 81 may be, for example, urethane foam. In this embodiment, the sound-absorbing material 81 covers all of the through-holes 51 c. However, the sound-absorbing material 81 may also cover only some of the through-holes 51 c, or the sound-absorbing material 81 may occupy the entire expansion chamber 51 d. By providing the sound-absorbing material 81, sound waves attempting to enter the expansion chamber 51 d are absorbed by the sound-absorbing material 81, further improving sound insulation performance (sound reduction performance). The sound-absorbing material 81 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 51.

[0041] A sheet-like sound-absorbing material 82 is provided on the outer surface of the straight pipe portion 53a of the sound-attenuation pipe 53 of the second sound-attenuation section 39 so as to cover the multiple through-holes 53c. In this embodiment, the sound-absorbing material 82 covers all of the through-holes 53c, but it may also cover some of the through-holes 53c, or the sound-absorbing material 82 may occupy the entire expansion chamber 53d. By providing the sound-absorbing material 82, sound waves attempting to enter the expansion chamber 53d are absorbed by the sound-absorbing material 82, further improving sound insulation performance (sound reduction performance). Note that the sound-absorbing material 82 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 53a.

[0042] As shown in Figure 9, a sheet-like sound-absorbing material 91 is provided on the outer surface of the straight pipe portion 68 of the sound-attenuation pipe 66 of the third sound-attenuation section 310 so as to cover the multiple through-holes 610. In this embodiment, the sound-absorbing material 91 covers all of the through-holes 610, but it may also cover some of the through-holes 610, or the sound-absorbing material 91 may occupy the entire expansion chamber 611 (see Figure 7). By providing the sound-absorbing material 91, sound waves attempting to enter the expansion chamber 611 are absorbed by the sound-absorbing material 91, further improving sound insulation performance (sound reduction performance). Note that the sound-absorbing material 91 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 68.

[0043] A sound-absorbing material 92 is provided inside the first folded portion 62. In this embodiment, the pad-shaped sound-absorbing material 92 is provided on the inner surface of the closed end 613 of the tubular member 612. By providing the sound-absorbing material 92, part of the sound waves (high frequencies) from the electric suction machine 36 that pass through the first ventilation passage 61 are absorbed by the sound-absorbing material 92, further improving sound insulation performance (noise reduction performance). Note that the sound-absorbing material 92 may also be provided on the inner surface surrounding the first folded portion 62.

[0044] Third Embodiment In the first embodiment of the electric vacuum cleaner 1 (see FIG. 3 ), the vacuum cleaner body 2 includes the first sound-reducing section 38, the second sound-reducing section 39, and the third sound-reducing section 310, and the suction port body 3 includes the suction port body-side sound-reducing section 24. However, one, two, three, or four of these four sound-reducing sections may be replaced with standard ventilation passages (i.e., ventilation passages without multiple through-holes). This configuration provides the sound-reducing effect achieved by providing two folded sections (first folded section 62 and second folded section 64) in the ventilation passage 35 downstream of the electric suction device 36 in the airflow direction to increase the overall length of the ventilation passage 35, while also providing the sound-reducing effect achieved by the sound-reducing sections that are not replaced with standard ventilation passages. In the second embodiment, one, two, three, or four of the four sound-reducing sections may be replaced with standard ventilation passages, and sound-absorbing material may be provided on the inner surface of the replaced standard ventilation passage. With this configuration, it is possible to obtain a sound reduction effect by lengthening the overall length of the ventilation passage 35 with the two folded sections, a sound reduction effect by the sound reduction section that has not been changed to a normal air passage, and a sound reduction effect by the sound-absorbing material.

[0045] Fourth Embodiment In the first embodiment of the electric vacuum cleaner 1 (see FIGS. 3 and 7 ), the first folded portion 62 and the second folded portion 64 are provided in the ventilation passage 35 downstream of the electric suction device 36 in the airflow direction. However, the second folded portion 64 may be omitted. In this case, the peripheral wall of the tubular member 612 forms part of the body 5 of the housing 4, the small ventilation holes 614 of the tubular member 612 form the exhaust port 11, and air is discharged to the outside through the small ventilation holes 614. This configuration achieves the sound reduction effect achieved by lengthening the ventilation passage 35 with the first folded portion 62, as well as the sound reduction effect achieved by the first sound reduction section 38, the second sound reduction section 39, and the third sound reduction section 310 of the vacuum cleaner body 2 and the suction port body-side sound reduction section 24 of the suction port body 3. In the second embodiment, the second folded portion 64 may also be omitted. With this configuration, it is possible to obtain a sound reduction effect by providing the first folded portion 62 and lengthening the ventilation passage 35, a sound reduction effect by the first sound reduction section 38, the second sound reduction section 39, the third sound reduction section 310 of the vacuum cleaner main body 2 and the suction port body side sound reduction section 24 of the suction port body 3, and a sound reduction effect by the sound-absorbing material.

[0046] Fifth Embodiment The first folded portion 62 and the second folded portion 64 of the electric vacuum cleaner 1 of the first embodiment (see FIGS. 3 and 7 ) may be omitted. In this case, the tubular member 612 is omitted, and air from the other-end opening 66b is discharged from the exhaust port 11 on the other end side. Even without the tubular member 612, some of the air from the other-end opening 66b hits the inner surface of the other end of the housing 4, folds back toward the one end, and is discharged from the exhaust port 11. This configuration achieves the sound reduction effects of the first sound reduction section 38, the second sound reduction section 39, and the third sound reduction section 310 of the vacuum cleaner body 2 and the suction port body-side sound reduction section 24 of the suction port body 3, as well as the sound reduction effect of the sound-absorbing material. The first folded portion 62 and the second folded portion 64 may also be omitted in the second embodiment. With this configuration, it is possible to obtain a sound reduction effect by the first sound reduction section 38, the second sound reduction section 39, the third sound reduction section 310 of the vacuum cleaner main body 2 and the suction port body side sound reduction section 24 of the suction port body 3, as well as a sound reduction effect by the sound-absorbing material.

[0047] (Sixth embodiment) In the first embodiment, the battery 8 is detachably attached to the battery attachment section 6 at the lower end 9a (one end 9a) of the vacuum cleaner body 2 of the electric vacuum cleaner 1 (see FIG. 1), but the battery 8 may be fixed to the battery attachment section 6, or may be detachably attached to the circuit board housing section 7, or may be housed within the circuit board housing section 7. Alternatively, the battery 8 may be disposed on the front surface of one end 9a of the trunk 5 of the vacuum cleaner body 2. The same applies to the second embodiment.

[0048] Seventh Embodiment In the first embodiment, the handle 10 of the vacuum cleaner 1 (see FIG. 1) is annular, but the handle 10 may be a straight rod or a rod with a bent portion. The same applies to the second embodiment.

Claims

1. An electric vacuum cleaner comprising a housing having an air intake and an exhaust port, a ventilation passage through which air from the air intake to the exhaust port, an electric suction unit provided in the ventilation passage, a dust collection unit provided in the ventilation passage upstream of the electric suction unit in the airflow direction, and a sound reduction unit which forms part of the ventilation passage upstream of the dust collection unit in the airflow direction and reduces noise including airflow sound, wherein the sound reduction unit is located within the housing.

2. An electric vacuum cleaner as described in claim 1, wherein the intake port is provided at one end side in the direction of the central axis of the housing, and the exhaust port is provided at the other end side in the direction of the central axis of the housing, and the ventilation passage has a first ventilation passage connected to the other end side of the electric suction machine, a second ventilation passage on the outer periphery of the first ventilation passage, a third ventilation passage on the outer periphery of the second ventilation passage, a first folding portion that turns back air flowing out from the other end opening on the other end side of the first ventilation passage and guides it to the second ventilation passage, and a second folding portion that turns back air flowing out from the one end opening on one end side of the second ventilation passage and guides it to the third ventilation passage.

3. The vacuum cleaner according to claim 1 or 2, further comprising an annular handle provided at the other end of the housing, and an operating section provided at the other end of the housing for switching the electric suction device on and off.

4. The vacuum cleaner according to claim 3, wherein the operating section is provided on the other end surface of the housing that intersects approximately perpendicularly with the central axis of the housing.

5. The vacuum cleaner according to claim 3, wherein the operating part is provided on a part of the handle which cannot be gripped.

6. The vacuum cleaner according to claim 1 or 2, further comprising a battery for supplying power to the electric suction unit, the battery being disposed on the outer surface of the housing in the vicinity of the intake port.

7. The vacuum cleaner according to claim 1 or 2, further comprising a battery for supplying power to the electric suction unit, the battery being disposed on the outer surface of the housing in the vicinity of the sound reduction section.

8. The vacuum cleaner according to claim 1 or 2, further comprising a detachable attachment at the air inlet.

9. The vacuum cleaner according to claim 1 or 2, wherein the sound reduction section has a sound reduction tube having a ventilated structure on at least a portion of its surrounding surface.

10. The vacuum cleaner according to claim 9, wherein the breathable structure is a plurality of through holes penetrating the inner and outer surfaces of the sound-reducing tube.

11. The vacuum cleaner according to claim 9, 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.

12. The vacuum cleaner according to claim 9, wherein the sound reduction section further has a sound reduction cover that covers the outer periphery of the sound reduction tube.

13. An electric vacuum cleaner comprising: a housing having an air intake port and an exhaust port; a ventilation passage for directing air from the air intake port to the exhaust port; an electric suction machine provided in the ventilation passage; and a dust collection section provided in the ventilation passage upstream of the electric suction machine in the airflow direction, wherein the air intake port is provided on one end side of the housing in the direction of the central axis, and the exhaust port is provided on the other end side of the housing in the direction of the central axis, and the ventilation passage has a first ventilation passage connected to the other end side of the electric suction machine, a second ventilation passage on the outer periphery of the first ventilation passage, a third ventilation passage on the outer periphery of the second ventilation passage, a first folding section that turns back air flowing out from the other end opening on the other end side of the first ventilation passage and guides it to the second ventilation passage, and a second folding section that turns back air flowing out from the one end opening on one end side of the second ventilation passage and guides it to the third ventilation passage.

14. An electric vacuum cleaner comprising a vacuum cleaner body including a housing having an air intake and an exhaust port, 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, a first sound reduction unit forming part of the ventilation passage upstream of the dust collection unit in the airflow direction and reducing noise including airflow sound, a second sound reduction unit forming part of the ventilation passage between the dust collection unit and the electric suction machine and reducing noise including the driving sound of the electric suction machine, and a third sound reduction unit forming part of the ventilation passage downstream of the electric suction machine in the airflow direction and reducing noise including the driving sound of the electric suction machine.

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