Patent Document

TECHNICAL FIELD 
   The present invention relates to an electric vacuum cleaner including first and second dust separation devices for separating vacuumed dust. 
   BACKGROUND 
   There is conventionally known an electric vacuum cleaner including a first dust separation device for separating dust and a second dust separation device for separating dust which has passed through the first dust separation device (refer to JP2006-6383A). 
   The electric vacuum cleaner includes the first dust separation device for separating dust vacuumed by a negative pressure of an electric fan, a first dust collection section for collecting the dust separated by the first dust separation device, the second dust separation device for separating the dust which has passed through the first dust separation device, a dust removing device for removing the dust adhering to the second dust separation device and a second dust collection section provided in the lower portion of the second dust separation device, for accumulating the dust removed by the dust removing device. An introduction opening provided in the upper portion of the second dust collection section is provided with an openable and closable opening and closing member. The opening operation and closing operation of the opening and closing member are conducted in conjunction with a pulling-out operation and a retracting operation of a power source cord. 
   More particularly, the opening and closing member closes the introduction opening of the second dust collection section, when pulling-out the power source code and the opening and closing member opens the introduction opening, when retracting the power source code. 
   In addition, when the power source cord is retracted, the dust removing device for removing the dust adhering to the second dust separation device is operated, disposing the dust removed by the second dust separation device into the second dust collection section from the introduction opening. 
   In operation of the electric fan, i.e., when the power source cord is pulled out, the introduction opening of the second dust collection section is closed by the opening and closing member. Accordingly, the dust accumulated in the second dust collection section is prevented from rising to adhere again to the second dust collection section. 
   However, the above electric vacuum cleaner has a problem in that its structure is complex, because the opening and closing operation of the opening and closing member requires an interlocking mechanism which operates in conjunction with the pulling-out operation and retracting operation of the power source cord. 
   SUMMARY 
   It is, therefore, an object of the present invention to provide an electric vacuum cleaner capable of opening and closing an introduction opening of a second dust collection section by means of a simple structure. 
   One aspect of the invention relates to an electric vacuum cleaner including a first dust separation device configured to separate dust vacuumed by a negative pressure of an electric fan, a first dust collection section for collecting the dust separated by the first dust separation device, a second dust separation device configured to separate the dust which has passed through the first dust separation device, a dust removing device configured to remove the dust adhering to the second dust separation device, a second dust collection section positioned in an upstream side of the second dust separation device and provided in a lower portion of the second dust separation device, for accumulating the dust removed by the dust removing device, a partition wall for zoning the first dust collection section and the second dust collection section, and an introduction opening for introducing the dust removed by the dust removing device into the second dust collection section, wherein the partition wall is provided with a communication opening for communicating the first dust collection section to the second dust collection section, the partition wall is provided with an opening and closing member for closing either of the introduction opening or the communication opening and switching the closing to the other by rotating, and the opening and closing member closes the introduction opening with the negative pressure by driving of the electric fan and closes the communication opening by its own weight when the electric fan is not driven. 
   Preferably, the communication opening is formed in an upper portion of the second dust collection section. 
   Advantageously, a bottom portion of the first dust collection section and a bottom portion of the second dust collection section are simultaneously opened, so as to simultaneously discharge the dust accumulated in the first dust collection section and the second dust collection section. 
   In a preferred embodiment, the dust removing device removes the dust adhering to the second dust separation device, when operation of the electric fan is stopped. 
   Advantageously, the second dust separation device comprises a pleated filter body. 
   In a preferred embodiment, the dust removing device removes the dust adhering to the pleated filter body by vibrating the pleated filter body. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing an external appearance of an electric vacuum cleaner according to the present invention. 
       FIG. 2  is a perspective view showing a body of the electric vacuum cleaner. 
       FIG. 3  is a vertical cross-sectional view showing the structure of the electric vacuum cleaner body. 
       FIG. 4  is a perspective view illustrating a dust collection container. 
       FIG. 5  is a perspective view illustrating the dust collection container shown in  FIG. 4  seen from another direction. 
       FIG. 6  is an explanatory view showing a structure of a round air path section of the dust collection container. 
       FIG. 7  is an explanatory view illustrating a fine dust collection section. 
       FIG. 8  is a cross-sectional view showing the electric vacuum cleaner body with an introduction opening closed by an opening and closing plate. 
       FIG. 9  is an explanatory view showing a fine dust collection section with the introduction opening closed by the opening and closing plate. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Hereinafter, an embodiment of an electric vacuum cleaner according to the present invention will be described with reference to the drawings. 
   Embodiment 
   An electric vacuum cleaner  10  shown in  FIG. 1  includes a vacuum cleaner body  20 . The front portion of the vacuum cleaner body  20  is provided with a hose connection port  21 . A dust collection hose  12  has one end detachably connected to the hose connection port  21  and has the other end provided with a hand operation unit  13 . An extension wand  14  is detachably connected to the hand operation unit  13 . A suction port  15  is detachably connected to the leading end portion of the extension wand  14 . The hand operation unit  13  is provided with an operation part  13 A including a plurality of operation switches S. 
   The vacuum cleaner body  20  includes a body case  30 , a dust collection container  50  detachably mounted on the body case  30  and a cover body  40  having the back portion connected to the body case  30  by a hinge so as to be openable and closable in the up and down direction, as illustrated in  FIG. 2 . 
   In addition, an electric fan  33  (refer to  FIG. 3 ) is built in a back portion  30 A of the body case  30 , and a cord reel  34  is disposed below the electric fan  33 . A plate-like mounting section  35  is provided in front of the body case  30  (on the left side in  FIG. 3 ). The dust collection container  50  is detachably mounted on the mounting section  35 . The cover body  40  and the mounting section  35  enclose the dust collection container  50 , so as to fasten the dust collection container  50  when the cover body  40  is closed. 
   The cover body  40  is provided with a tube portion  22  as shown in  FIG. 3 . The leading end of the tube portion  22  is the hose connection port  21  and the back end of the tube portion  22  is a connection opening  23 . 
   A front opening (not shown) is formed in a front wall portion  31  (reference to  FIG. 2 ) of the back portion  30 A. The front opening communicates with a suction opening  33 A of the electric fan  33  via a communication air path (not shown). The communication air path opposed to the front opening is provided with a dust removing device  90 . 
   The dust removing device  90  includes a reciprocating body (not shown) for reciprocating in the width direction of the body case  30  (in the direction orthogonal to the page space of  FIG. 3 ) and a projection  91  provided in the reciprocating body. The projection  91  shallowly engages with a top portion of a pleat of an after-mentioned pleated filter body  100 , and the projection  91  moves over the top portions of the pleat by the reciprocating of the reciprocating body. The dust removing device  90  thereby removes the dust adhering to the pleated filter body  100  by vibrating the pleated filter body  100 . 
   The reciprocating body reciprocates for a predetermined time every time the driving of the electric fan  33  is stopped. 
   As shown in  FIGS. 4 ,  5 , the dust collection container  50  includes a round air path section  51  formed on the upper portion thereof, a dust collection section (a first dust collection section)  60  formed below the round air path section  51 , a negative pressure room  70  formed at the back of the dust collection section  60 , and a bottom pad  80 . 
   The round air path portion  51  includes a dust separation section (a first dust separation device)  52  provided in the central portion thereof and a circular arc round air path  53  provided around the dust separation section  52 , as shown in  FIG. 6 . A leading end opening  54  of the leading end of the round air path  53  is connected to the connection opening  23  of the tube portion  22  of the cover body  40  as shown in  FIG. 3 . The round air path  53  communicates into the dust collection section  60  via a back end opening  55 . Moreover, the round air path  53  includes an opening  57  which is formed in the bottom portion in the middle of the round air path  53  and communicates with the negative pressure room  70 . A net filter F 2  is stretched to the opening  57 . 
   The dust separation section  52  includes a frame (not show) having an almost cylindrical shape and a net filter F 1  stretched to the frame. The bottom portion of the dust separation section  52  opens, such that the dust separation section  52  communicates with the negative pressure room  70  via an opening  56 . 
   A dividing wall  61  provided in the back portion of the dust collection section  60  includes an opening  62  which communicates with the negative pressure room  70 . A lower portion wall  61 A of the dividing wall  61  includes a communication hole (communication opening)  63  positioned in an upper portion of a fine dust collection section  74 . More particularly, the communication hole  63  is formed below the opening  62 . A net filter (the first dust separation device) F 3  is stretched to the opening  62 . 
   A frame  71  for detachably installing a pleated filter body (a second dust separation device)  100  is integrally formed in the back portion of the negative pressure room  70  (on the right side in  FIG. 5 ). A back end opening  72  of the frame  71  is connected to the front opening (not shown) of the body case  30  shown in  FIG. 3 . 
   A lower portion back wall  73  is formed in the lower portion of the frame  71 . The fine dust collection section (the second dust collection section)  74  includes a space surrounded by the lower portion back wall  73 , the lower portion wall  61 A of the dividing wall (partition wall)  61  of the dust collection section  60  and the bottom pad  80 . The fine dust collection section  74  communicates with the dust collection section  60  via the communication hole  63  of the dividing wall  61 . In addition, as shown in  FIG. 7 , an introduction opening  75  is formed between a lower frame wall  71 A of the frame  71  and the lower portion wall  61 A of the dividing wall  61  as shown in  FIG. 7 . 
   In addition, one end portion (upper portion in  FIG. 7 ) of an opening and closing plate (opening and closing member)  76  for closing the introduction opening  75  is supported by the lower portion of the dividing wall  61  of the dust collection section  60 . The opening and closing plate  76  is rotatable upon one end portion of the opening and closing plate  76 . The opening and closing plate  76  closes the communication hole  63  of the dividing wall  61  by its own weight and opens the introduction opening  75  of the fine dust collection section  74 , when the electric fan  33  is not driven. The opening plane of the communication hole  63  is configured such that the opening and closing plate  76  rotates to close the introduction opening  75  (refer to  FIG. 9 ), if the pressure in the negative pressure room  70  becomes negative by the driving of the electric fan  33 . 
   The bottom pad  80  is a rotatable in the clockwise direction about an axis  81  illustrated in  FIG. 3 . If a button B provided in a holding portion  58  of the dust collection container  50  is pressed, the bottom portion of the dust collection section  60  and the bottom portion of the fine dust collection section  74  are opened. Accordingly, the dust accumulated in the dust collection section  60  and the fine dust collection section  74  can be disposed. 
   [Operation] 
   Next, the operation of the electric vacuum cleaner having the above structure will be explained. 
   At first, as shown in  FIG. 2 , the dust collection container  50  is mounted on the mounting section  35  of the body case  30 , and the cover body  40  is closed. As shown in  FIG. 1 , one end of the dust collection hose  21  is connected to the hose connection port  21  of the cover body  40 . 
   In this state, as illustrated in  FIGS. 3 ,  7 , the opening and closing plate  76  of the dust collection container  50  closes the communication hole  63  of the dividing wall  61  by its own weight. 
   If the switch S of the operation part  13 A is operated, the electric fan  33  is driven. By the driving of the electric fan  33 , air is sucked from the suction opening  33 A of the electric fan  33 , creating a negative pressure in the negative pressure room  70  of the dust collection container  50 . Thereby, the opening and closing plate  76  rotates by this negative pressure so as to close the introduction opening  75  as shown in  FIGS. 8 ,  9 . 
   If the introduction opening  75  is closed by the opening and closing plate  76 , the fine dust accumulated in the fine dust collection section  74  is prevented from rising to adhere to the pleated filter body  100 . 
   In addition, since the communication hole  63  of the dividing wall  61  of the dust collection container  50  is formed in the upper portion of the fine dust collection section  74 , the air flows as illustrated by the arrows in  FIGS. 7 ,  9  when the opening and closing plate  76  rotates to close the introduction opening  75 . Accordingly, the dust accumulated in the fine dust collection section  74  is not raised by this air. 
   As described above, the opening and closing plate  76  rotates by the driving of the electric fan  33  so as to close the introduction opening  75 ; thus, the structure of the opening and closing plate  76  is simplified. 
   On the other hand, a negative pressure is created in the dust collection section  60  and the round air path  53  by the negative pressure of the negative pressure room  70  of the dust collection container  50 . This negative pressure acts on the tube portion  22 , the dust collection hose  12 , the extension wand  14  and the suction port  15 , so as to vacuum the dust together with air from the suction port  15 . 
   The vacuumed dust and air are sucked into the hose connection port  21  of the cover body  40  via the extension wand  14  and the dust collection hose  12 . The dust and air sucked into the hose connection port  21  is sucked into the dust collection section  60  through the round air path  53  of the dust collection container  50 . 
   A part of the air is separated from the dust by the round air path  53 , and the separated air is sucked to the negative pressure room  70  through the net filters F 1 , F 2 . 
   The dust and air sucked into the dust collection section  60  are separated, and the separated air is sucked to the negative pressure room  70  through the net filter F 3  and also the dust is collected in the dust collection section  60 . 
   The air sucked to the negative pressure room  70  is sucked to the suction opening  33 A of the electric fan  33  via the pleated filter body  100  or the like. The sucked air is discharged from a discharging port  33 B of the electric fan  33 , and is discharged outside from a discharging port (not shown) of the body case  30 . If the driving of electric fan  33  is stopped, the sucking of dust and air from the suction port  15  is stopped. The degree of vacuum of the negative pressure room  70  of the dust collection container  50  is thereby increased to atmospheric pressure. The opening and closing plate  76  of the dust collection container  50  rotates by its own weight, so as to close the communication hole  63  of the dividing wall  61  as shown in  FIGS. 3 ,  7 , opening the introduction opening  75  of the fine dust collection section  74 . 
   On the other hand, the reciprocating body (not shown) of the dust removing device  90  reciprocates for a predetermined time by stopping the driving of the electric fan  33 ; thus, the dust adhering to the pleated filter body  100  is removed. The dust removed from the pleated filter body  100  is disposed into the fine dust collection section  74  because the introduction opening  75  is opened as shown in  FIG. 7 . 
   In order to dispose of the dust accumulated in the dust collection section  60  and the fine dust collection section  74  of the dust collection container  50 , the dust collection container  50  is removed from the body case  30 , and the bottom pad  80  rotates in the clockwise direction about the axis  81  to open the bottom portion of the dust collection section  60  and the fine dust collection section  74 . Accordingly, the dust accumulated in the dust collection section  60  and the fine dust collection section  74  is disposed. 
   According to one embodiment of the present invention, the introduction opening of the second dust collection section can be opened and closed by means of a simple structure; thus, the re-adhesion of dust can be prevented. 
   The present application is based on and claims priority from Japanese application No. 2006-99862 filed on Mar. 31, 2006, the disclosure of which is hereby incorporated by reference herein in its entirety. 
   Although the present invention has been described in terms of an exemplary embodiment, it is not limited thereto. It should be appreciated that variations may be made in the embodiment described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. In addition, the number, position, shape, or the like of the components are not limited to the above embodiment, and can be changed to the number, position, shape or the like of components preferable for conducting the present invention. Moreover, no element or component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.

Technology Category: 1