Vacuum cleaner

Abstract

A vacuum cleaner includes an electric blower that sucks dust through a suction connecting port, a first dust separating unit for separating the dust and air sucked into the suction connecting port from each other, and a pleat filter for separating the dust and air passing through a first dust separating unit. The vacuum cleaner further includes an external-air introducing air passage for introducing external air toward an upstream side of the pleat filter, a rotational fan for dropping off dust adhering to the pleat filter by the introduced external air, and a return air passage for returning the dust dropped off from the rotating fan toward the upstream side of the first dust separating unit by the introduced external air.

1 . A vacuum cleaner comprising:
 an electric blower for sucking dust through a suction connecting port;   a dust separating unit for separating the dust and air sucked into the suction connecting port from each other to thereby collect the dust;   a collecting unit for collecting the dust passing through the dust separating unit, the collecting unit being provided separately from the dust separating unit;   a dust removal unit for dropping off the dust collected by the collecting unit; and   a return mechanism for returning the dust dropped off from the collecting unit by the dust removal unit toward an upstream side of the dust separating unit,   the dust returned by the return mechanism being collected by the dust separating unit.   
   
   
       2 . The vacuum cleaner according to  claim 1 , further comprising an external-air introducing air passage provided for introducing external air toward the upstream side of the dust separating unit, wherein the return mechanism has a return air passage configured to return the dust dropped off from the collecting unit by the dust removal unit toward the upstream side of the dust separating unit by the external air introduced through the external-air introducing air passage. 
   
   
       3 . The vacuum cleaner according to  claim 2 , wherein the collecting unit has a pleat filter, and the dust removal unit is provided with a rotating fan contacting the pleat filter and driven by the external air introduced from the external-air introducing air passage to thereby drop off dust collected by the pleat filter. 
   
   
       4 . A vacuum cleaner comprising:
 an electric blower for sucking dust through a dust suction port;   a first dust separating unit for separating the dust and air sucked into the dust suction port from each other;   a second dust separating unit for separating the dust and air passing through the first separating unit;   a first blocking unit for blocking an air passage located on a downstream side of the second dust separating unit and on an upstream side of the electric blower;   a second blocking unit for blocking an air passage between the first dust separating unit and the second dust separating unit;   a detour air passage communicating an upstream portion of the electric blower with a downstream portion of the first dust separating unit;   a third blocking unit for blocking the detour air passage;   a dust removal unit for dropping off the dust adhering to the second dust separating unit;   an external-air introducing air passage for introducing external air toward the upstream side of the second dust separating unit;   a control unit for controlling the first, second and third blocking units; and   a return air passage for returning the dust dropped off by the dust removal unit toward the upstream side of the first dust separating unit by the external air introduced from the external-air introducing air passage so that the returned dust is collected by the first dust separating unit.   
   
   
       5 . The vacuum cleaner according to  claim 4 , wherein the second dust separating unit is provided with a pleat filter, and the dust removal unit is provided with a rotating fan contacting to the pleat filter and driven by the external air introduced from the external-air introducing air passage to thereby drop off dust collected by the pleat filter. 
   
   
       6 . A vacuum cleaner comprising:
 an electric blower for sucking dust through a dust suction port;   a first dust separating unit for separating the dust and air sucked into the dust suction port from each other;   a second dust separating unit for separating the dust and air passing through the first separating unit;   a first blocking unit for blocking an air passage located on a downstream side of the second dust separating unit and on an upstream side of the electric blower;   a second blocking unit for blocking an air passage between the first dust separating unit and the second dust separating unit;   a dust removal unit for introducing external air toward an upstream side of the second dust separating unit and dropping off dust adhering to the second dust separating unit by the external air;   a detour air passage flowing the introduced external air to a downstream side of the second dust separating unit; and   a third blocking unit for catching the dust passing through the detour air passage together with the external air.   
   
   
       7 . The vacuum cleaner according to  claim 6 , wherein the second dust separating unit is provided with a pleat filter, and the dust removal unit is provided with a rotating fan contacting to the pleat filter and driven by the external air introduced by an external-air introducing air passage to thereby drop off dust collected by the pleat filter.