Patent Publication Number: US-10765280-B2

Title: Vacuum cleaner and control method for the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY 
     The present application claims priority under 35 U.S.C. § 365 to International Patent Application No. PCT/KR2015/014084 filed Dec. 22, 2015, entitled “VACUUM CLEANER AND CONTROL METHOD THEREFOR”, and through Korean Patent Application No. 10-2014-0190408, which was filed on Dec. 26, 2014, each of which is incorporated herein by reference into the present disclosure as if fully set forth herein. 
     TECHNICAL FIELD 
     Embodiments of the present disclosure relate to a vacuum cleaner to reduce a noise generated when cleaning and a control method for the same. 
     BACKGROUND 
     In general, a vacuum cleaner is an apparatus configured to perform a clean by suctioning foreign materials, e.g., dust together with air using a suction force generated by a fan rotated by a motor, and by collecting the dust by separating the foreign materials contained in the suctioned air from the air. 
     The vacuum cleaner includes a general vacuum cleaner configured to perform a clean such that a user moves it by directly applying a force and a robot cleaner configured to perform a clean by automatically moving without the user operation. 
     When the vacuum cleaner performs a clean, the noise is inevitably generated in a process of suctioning and discharging air through a flow path inside the main body. 
     SUMMARY 
     Therefore, it is an aspect of the present disclosure to provide a vacuum cleaner having a resonator capable of efficiently canceling a noise generated during air passes through a flow path inside the vacuum cleaner, when cleaning, and a control method for the same. 
     In accordance with one aspect of the present disclosure, a vacuum cleaner includes a suction unit configured to suction and discharge air, at least one flow path configured to guide air to be suctioned into the suction unit or to be discharged from the suction unit, and at least one resonator connected to the at least one flow path to cancel a noise, wherein the at least one resonator is configured to change a resonant frequency to be cancelled. 
     The resonator may include a resonance container formed in a hollow container shape to form a resonance space and a piston installed to be movable forward and backward in the resonance container. 
     The vacuum cleaner may further include a driving device configured to move the piston forward and backward. 
     The driving device may include a driving motor, a pinion rotated by the driving motor, and a rack connected to the piston and engaged with the pinion. 
     The vacuum cleaner may further include a lever configured to transmit an external force to the piston. 
     The at least one flow path may include a suction flow path configured to guide air suctioned into the suction unit and a discharge flow path configured to guide air discharged from the suction unit, wherein the at least one resonator is installed in at least one of the suction flow path and the discharge flow path. 
     The resonator may include a resonance container formed in a hollow container shape to form a resonance space and a connection pipe configured to connect the flow path to the resonance container, wherein a length of the connection pipe is variable. 
     The connection pipe may include a first connection pipe extending from the flow path and a second connection pipe extending from the resonance container and movably installed in the first connection pipe. 
     The at least one flow path may include a main flow path and a bypass flow path diverged from the main flow path and then joined into the main flow path, wherein the resonator is connected to the bypass flow path. 
     The resonator may include a resonance container formed by an expandable and contractible bellows tube. 
     In accordance with another aspect of the present disclosure, a vacuum cleaner includes at least one flow path configured to guide suction or discharge of air, and at least one resonator connected to the at least one flow path, wherein the resonator comprises a resonance container configured to change a volume of an internal space thereof forming a resonance space. 
     The vacuum cleaner may further include a piston installed to be movable in the resonance container and configured to change the volume of the resonance space while moving. 
     The resonance container may be formed by an expandable and contractible bellows tube. 
     In accordance with another aspect of the present disclosure, a vacuum cleaner includes at least one flow path configured to guide suction or discharge of air, and at least one resonator connected to the at least one flow path, wherein the resonator comprises a resonance container forming a resonance space and a connection pipe connecting the flow path to the resonance container, wherein a length of the connection pipe is variable. 
     The connection pipe comprises a first connection pipe extending from the flow path and a second connection pipe extending from the resonance container and movably installed in the first connection pipe. 
     In accordance with another aspect of the present disclosure, a control method for a vacuum cleaner includes allowing air to flow via a flow path by driving a suction unit, detecting a frequency of noise generated in the flow path during the air flows, and changing a resonant frequency of a resonator connected to the flow path so that the resonant frequency corresponds to the frequency of the noise. 
     The resonator may include a resonance container formed in a hollow container shape to form a resonance space therein, wherein the change in the resonant frequency of the resonator is performed according to the change in a volume of the resonance space. 
     The resonator may include a connection pipe configured to connect the flow path to the resonance container, wherein the change in the resonant frequency of the resonator is performed according to the change in a length of the connection pipe. 
     In accordance with one aspect of the present disclosure, it may be possible to actively cope with a noise which is generated with various levels according to an operation mode of a vacuum cleaner, since the vacuum cleaner has a resonator capable of changing a resonate frequency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the present disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a schematic view illustrating a vacuum cleaner according to a first embodiment of the present disclosure; 
         FIG. 2  is a sectional view illustrating a suction unit and a resonator applied to a vacuum cleaner according to the first embodiment of the present disclosure; 
         FIG. 3  is an exploded perspective view illustrating a resonator applied to the vacuum cleaner according to the first embodiment of the present disclosure; 
         FIG. 4  is a sectional view illustrating an operation of the resonator applied to the vacuum cleaner according to the first embodiment of the present disclosure; 
         FIG. 5  is a control block diagram of a vacuum cleaner according to the first embodiment of the present disclosure; 
         FIG. 6  is a control flowchart of the vacuum cleaner according to the first embodiment of the present disclosure; 
         FIG. 7  is a sectional view illustrating a suction unit and a resonator applied to a vacuum cleaner according to a second embodiment of the present disclosure; 
         FIG. 8  is a cross-sectional view illustrating a resonator applied to a vacuum cleaner according to a third embodiment of the present disclosure; 
         FIGS. 9 and 10  are sectional views illustrating operations of a resonator applied to a vacuum cleaner according to a fourth embodiment of the present disclosure; 
         FIG. 11  is a schematic view illustrating an installation state of a resonator applied to a vacuum cleaner according to a fifth embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a vacuum cleaner according to a first embodiment of the present disclosure will be described in detail with reference to drawings. 
     In this embodiment, a robot cleaner configured to clean a floor while automatically traveling without the user operation will be described as an example of a vacuum cleaner. 
     As illustrated in  FIG. 1 , a vacuum cleaner  1  may include a body  10  formed in a substantially disk shape to form an exterior of the vacuum cleaner  1 ; a suction unit  20  disposed inside of the body  10  to allow the outside air together with foreign materials to be suctioned into the inside of the body  10  and to be discharged; and a dust collector  30  configured to filter the foreign materials, e.g., dust, contained in the air suctioned by the suction unit  20 . 
     An inlet  11  to which the air is suctioned, and an outlet  12  to which the air in which the foreign material is filtered is discharged may be disposed in the body  10 . A flow path  13  and  14  configured to guide the air suctioned via the inlet  11  to be discharged via the outlet  12  by passing through the dust collector  30  and the suction unit  20  may be provided inside of the body  10 . The inlet  11  may be provided in the lower front side of the body  10  and the inlet  11  may be provided in the rear side of the body  10 . 
     The flow path  13  and  14  may include a suction flow path  13  configured to guide the air suctioned via the inlet  11 , to the suction unit  20 , and a discharge flow path  14  configured to guide the air discharged from the suction unit  20 , to the outlet  12 . 
     A resonator  40  may be connected to the flow path  13  and  14  to cancel a noise generated during the air is suctioned or discharged. According to the embodiment, two resonators  40  may be provided and thus one resonator  40  may be connected to the suction flow path  13  and the other resonator  40  may be connected to the discharge flow path  14 . Therefore, it is possible to separately cancel the noise generated in the process of suctioning air through the suction flow path  13  and the noise generated in the process of discharging the air through the discharge flow path  14 . 
     The dust collector  30  may be disposed adjacent to the inlet  11  and configured to allow the foreign materials, which are contained in the air introduced via the inlet  11 , to be filtered before transmitted to the suction unit  20 . A component, e.g., a filter (not shown) may be disposed inside of the dust collector  30 . 
     As illustrated in  FIG. 2 , the suction unit  20  may include a motor  21  configured to generate a torque by including a stator  21   a , a rotor  21   b  and an axis  21   c ; a blowing fan  22  connected to the axis  21   c  of the motor  21  to be rotated to move the air along the flow path  13  and  14 ; and a housing  23  configured to accommodate the motor  21  and the blowing fan  22 . 
     According to the embodiment, since the motor  21  applied to the suction unit  20  is configured to adjust the number of revolutions, it is possible to change the suction force and the blowing force generated by the suction unit  20 . This is to allow the vacuum cleaner  1  to operate in various modes depending on a cleaning environment, e.g., a floor condition or a user&#39;s selection. 
     For example, the vacuum cleaner  1  may be operated in an operation mode, wherein the operation mode may include a quite cleaning mode for minimizing the noise generated in the vacuum cleaner  1  despite of a weak suction force, a regular cleaning mode for cleaning a general floor with a normal suction force, a carpet cleaning mode for cleaning the carpet, and a power cleaning mode for cleaning the floor with a stronger suction force despite of generating a loud noise. 
     According to the change in the operation mode as mentioned above, the suction force and the blowing force generated by the suction unit  20  may vary, and thus the frequency of the noise generated by the suction unit  20  may vary according to the change in the suction force and the blowing force. 
     When the resonator  40  is configured to cancel a certain frequency, it may be impossible to correspond to the noise changed according to the change in the operation mode of the vacuum cleaner  1 . 
     Therefore, according to the embodiment of the present disclosure, the resonator  40  may be configured to change a resonant frequency to cancel the noise and thus it may be possible to actively deal with the noise variably changed according to the change in the operation mode of the vacuum cleaner  1 . 
     As illustrated in  FIG. 3 , the resonator  40  may include a resonance container  41  formed in a hollow container shape to form a resonance space  41   a ; a piston  42  installed to be movable in the resonance container  41  to change a volume of the resonance space  41   a  inside of the resonance container  41 ; and a connection pipe  43  configured to connect the flow path  13  and  14  to the resonance container  41 . Therefore, the volume of the resonance space  41   a  may be changed according to the movement of the piston  42 , and thus the resonant frequency of the resonator  40  may be changed. According to the embodiment, the inside of the resonance container  41  may have an approximately rectangular shape but the shape of the resonance container  41  is not limited thereto. Therefore, the inside of the resonance container  41  may be formed in various other shapes, e.g., a cylindrical shape. 
     The resonant frequency of the resonator  40  can be calculated through the following equation. In the following equation, “fr” represents a resonant frequency, “A” represents a cross-sectional area of a connection pipe, “l” represents a length of a connection pipe, “V” represents a volume of the resonance space  41   a  and “c” represents the speed of sound. 
     
       
         
           
             fr 
             = 
             
               
                 c 
                 
                   2 
                   ⁢ 
                   π 
                 
               
               ⁢ 
               
                 
                   A 
                   
                     l 
                     × 
                     V 
                   
                 
               
               ⁢ 
               Hz 
             
           
         
       
     
     Therefore, it may be possible to effectively cancel the noise generated in the flow path  13  and  14  by changing the volume of the resonance space  41   a  inside of the resonance container  41  by moving the piston  42  to correspond to the rotational speed of the motor  21 . 
     The piston  42  may be moved by the power generated by a driving device  50 . According to the embodiment, the driving device  50  may include a driving motor  51 ; a pinion  52  mounted on a shaft of the driving motor  51 ; and a rack  53  mounted on the piston  42  and engaged with the pinion  52 . Therefore, as the pinion  52  rotates in the forward and reverse directions by the driving motor  51 , the rack  53  may move and accordingly the piston  42  may move in the resonance container  41  to change the volume of the resonance space  41   a . According to the embodiment, the driving device  50  may be configured with the driving motor  51 , the pinion  52  and the rack  53 , but is not limited thereto. Therefore, the variety of driving devices may be used to move the piston  42 . 
     As illustrated in  FIG. 2 , when the volume of the resonance space  41   a  is formed to be large by the piston  42 , the frequency of the noise, which is to be cancelled by the resonator  40 , may be relatively low, and as illustrated in  FIG. 4 , when the volume of the resonance space  41   a  is formed to be small by the piston  42 , the frequency of the noise, which is to be cancelled by the resonator  40 , may be relatively high. Therefore, although the frequency of the noise, which is generated in the suction flow path  13  and the discharge flow path  14 , is changed according to the change in the operation mode of the vacuum cleaner  1 , it may be possible to change the resonant frequency of the noise of the resonator  40  to correspond to the frequency of the noise by moving the piston  42 , and thus it may be possible to effectively deal with the noise generated in the flow path  13  and  14 . 
     As illustrated in  FIG. 5 , the vacuum cleaner  1  may include a processor  100  configured to control motions of the vacuum cleaner  1 ; a position sensor  110  configured to detect a wall, an obstacle and a floor; and a travelling device  130  configured to allow the vacuum cleaner  1  to automatically move by including a travelling motor (not shown) generating a torque and a wheel (not shown) rotating by receiving the torque from the travelling motor. 
     Therefore, the vacuum cleaner  1  may perform a cleaning while travelling through the travelling device to avoid a collision or falling using the information about the wall, the obstacle and the floor detected by the position sensor  110 . 
     The vacuum cleaner  1  may include a noise sensor  120  configured to detect a noise generated in the suction flow path  13  and the discharge flow path  14  during the suction unit  20  is operated. Therefore, the processor  100  may receive information about the noise sensed by the noise sensor  120  and then control the resonator  40  so that the resonator  40  has a resonance frequency corresponding to the frequency of the noise sensed by the noise sensor  120 . In this embodiment, the processor  100  may control the driving device  50  to move the piston  42 , thereby changing the volume of the resonance space  41   a  provided inside the resonance container  41 . 
     Therefore, when a user operates the vacuum cleaner  1 , the suction unit  20  may suction air via the suction flow path  13  and discharge the air via the discharge flow path  14 . In the process of suctioning and discharging of the air, the noise may be generated in the suction flow path  13  and the discharge flow path  14 . The frequency of the noise may be detected by the noise sensor  120  and the information of the frequency of the noise may be transmitted to the processor  100 . The processor  100  may move the piston  42  by controlling the driving device  50  to change the volume of the resonance space  41   a  in the resonance container  41 . As the volume of the resonance space  41   a  is changed, the resonant frequency of the resonator  40  may be changed to correspond to the frequency of the noise generated in the suction flow path  13  and the discharge flow path  14  so as to cancel the noise generated in the flow path  13  and  14 . 
     The control method of the vacuum cleaner will be described below. 
     As illustrated in  FIG. 6 , it may be checked whether the suction unit  20  is operated or not ( 10 ), and when it is checked that the suction unit  20  is operated, the noise sensor  120  may detect the frequency of the noise generated in the flow path  13  and  14  ( 20 ). 
     The processor  100  may receive the information about the frequency of the noise detected by the noise sensor  120  and then allow the resonant frequency of the resonator  40  to be changed to correspond to the frequency of the noise detected by the noise sensor  120  ( 30 ). According to the embodiment, the driving device  50  may allow the volume of the resonance space  41   a  in the resonance container  41  to be changed by moving the piston  42 . According to the embodiment, the change in the resonant frequency of the resonator  40  may be performed by changing the volume of the resonance space  41   a  in the resonance container  41 , but is not limited thereto. Therefore, according to a third embodiment described later, the change in the resonant frequency of the resonator  40  may be performed by changing a length of a connection pipe  43 - 2 . 
     According to the embodiment, it may be possible to change the resonant frequency of the resonator  40  by detecting the noise using the noise sensor  120 , but is not limited thereto. Since the frequency of the noise is indirectly detected by using the flow rate of the air passing through the suction flow path  13  and the discharge flow path  14 , the vacuum cleaner  1  may include a flow rate sensor (not shown) configured to detect the flow rate of the air passing the suction flow path  13  and the discharge flow path  14 . 
     Alternatively, without a configuration corresponding to the noise sensor  120 , the vacuum cleaner  1  may allow the resonant frequency of the resonator  40  to be changed to a predetermined value according to the operation mode selected by a user. 
     According to the embodiment, the resonator  40  is installed in the suction flow path  13  and the discharge flow path  14 , respectively, but is not limited thereto. It may be possible to install the resonator  40  in any one of the suction flow path  13  and the discharge flow path  14 . Alternatively, it may be possible to install the resonator  40  configured to change the resonant frequency, in any one of the suction flow path  13  and the discharge flow path  14  and to install a general resonator configured to cancel a certain resonate frequency, in the other of the suction flow path  13  and the discharge flow path  14 . 
     According to the first embodiment, the piston  42  may be moved forward and backward by the piston  42  using the power generated by the driving device  50 , but is not limited thereto. According to a second embodiment as illustrated in  FIG. 7 , the piston  42  may be connected to a lever  44  exposed to the outside of the body  10  of the vacuum cleaner  1  so that a user may move the piston  42  by directly applying a force to the piston  42  of a resonator  40 - 1  through the lever  44 . 
     According to the above mentioned embodiments, the resonant frequency may be changed by changing the volume of the resonance space  41   a  by moving the piston  42 , but is not limited thereto. According to the third embodiment as illustrated in  FIG. 8 , it may be configured to change a length of a connection pipe  43 - 2  while maintaining a volume of a resonance space  41   a - 2  inside of a resonance container  41 - 2 , and thus it may be possible to change the resonant frequency of a resonator  40 - 2  by changing a length of the connection pipe  43 - 2 . 
     According to the third embodiment, the connection pipe  43 - 2  applied to the vacuum cleaner  1  may include a first connection pipe  43   a  connected to the flow path  13  and  14 ; and a second connection pipe  43   b  connected to the resonance container  41 - 2  and movably installed in the first connection pipe  43   a . The driving device  50  may include a driving motor  51  and a pinion  52  and a rack  53 , wherein the rack  53  may be installed in the resonance container  41 - 2 . 
     When moving the resonance container  41 - 2  using the driving device  50 , the resonance container  41 - 2  together with the second connection pipe  43   b  may be moved and thus an entire length of the connection pipe  43 - 2  may be changed. Accordingly, the resonant frequency of the resonator  40 - 2  may be changed. 
       FIGS. 9 and 10  illustrate a resonator  40 - 3  applied to a vacuum cleaner  1  according to a fourth embodiment of the present disclosure. 
     The resonator  40 - 3  may include a resonance container  41 - 3  formed by an expandable and contractible bellows tube; a guide rod  45  installed on one side of the resonance container  41 - 3  to guide the expansion and the contraction of the resonance container  41 - 3 ; and a driving device  50  configured to transfer the guide rod  45 . The driving device  50  may include a driving motor  51  and a pinion  52  and a rack  53 , as the same as the above mentioned embodiment, wherein the rack  53  may be installed in the guide rod  45 . When the guide rod  45  is moved by the driving device  50 , the resonance container  41 - 3  may be contracted and thus the volume of a resonance space  41   a - 3  provided therein may be changed. Accordingly, the resonant frequency, which is to be cancelled by the resonator  40 - 3  may be changed. 
       FIG. 11  illustrates a state in which a resonator  40  applied to a vacuum cleaner  1  is installed according to a fifth embodiment of the present disclosure. 
     According to the embodiment, a vacuum cleaner  1  may include a main flow path, i.e., a suction flow path  13  and a discharge flow path  14  directly connected to a suction unit  20  and two bypass flow paths  15  diverged from the suction flow path  13  or the discharge flow path  14  and then joined into the suction flow path  13  or the discharge flow path  14 , wherein the resonator  40  may be installed in the two bypass flow paths  15 . The bypass flow path  15  may have a smaller diameter than the suction flow path  13  and the discharge flow path  14  so that most of the air flows via the suction flow path  13  and the discharge flow path  14 . 
     When it is impossible to secure a space in the surround of the suction flow path  13  and the discharge flow path  14  for installing the resonator  40 , the resonator may be directly connected to the suction flow path  13  or the discharge flow path  14  using the bypass flow path  15 . 
     According to the embodiment, two bypass flow paths  15  are provided and then a single bypass flow path  15  is connected to the suction flow path  13  and the discharge flow path  14 , respectively, but is not limited thereto. Alternatively, a single bypass flow path  15  may be connected to any one of the suction flow path  13  and the discharge flow path  14 . In this case, the resonator  40  may be directly connected to the suction flow path  13  or the discharge flow path  14  to which the bypass flow path  15  is not connected, and alternatively, the resonator  40  may be not connected to the suction flow path  13  or the discharge flow path  14  to which the bypass flow path  15  is not connected. 
     Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.