Patent Publication Number: US-2022211234-A1

Title: Vacuum cleaner

Description:
This application claims priority to Chinese Patent Application No. 202020346376.9 filed Mar. 18, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present application relates to a vacuum cleaner, for example, an air passage switching device of the vacuum cleaner. 
     BACKGROUND 
     A filter of a vacuum cleaner gradually becomes blocked after being used for some time, resulting in a decrease in the filtration performance. Patent application US20160331198 published on Nov. 17, 2016 discloses a vacuum cleaner. This vacuum cleaner has two sets of butterfly valves and two sets of solenoid driving devices for driving the corresponding butterfly valves to move. The two sets of butterfly valves switch the air passage so that the airflow discharged by the fan may flow through one of the filters in the reverse direction, the dust and other blockages attached to this filter are blown away, and thus the blockages in this filter can be effectively reduced. The present application provides an air passage switching apparatus with another configuration, which may also be effectively applied to the blockage cleaning of the filter of the vacuum cleaner. 
     SUMMARY 
     The present disclosure provides a vacuum cleaner provided with a switching valve apparatus that switches an air passage more conveniently. 
     A vacuum cleaner includes a dust collection container, a fan, a first filter, a second filter, and a switching valve apparatus. The switching valve apparatus includes an outer casing and a counterflow air passage at least partially located in the outer casing. The outer casing is provided a first vent opening corresponding to the first filter and a second vent opening corresponding to the second filter. The first vent opening and the second vent opening are disposed on the outer periphery of the outer casing and arranged side by side along the circumferential direction of the outer casing. The counterflow air passage is rotatable to different angular positions relative to the outer casing so that the counterflow air passage may selectively communicate with the first vent opening or communicate with the second vent opening or not be aligned with and thus not in communication with the first vent opening and the second vent opening. The counterflow air passage is provided with a counterflow air outlet. In the case where the counterflow air passage is at a first angular position, the counterflow air outlet is staggered with the first vent opening and the second vent opening, and the outer casing seals the counterflow air outlet. In this case, under the suction of the fan, the airflow filtered by the first filter flows through at least the first vent opening to the suction port of the fan, and the airflow filtered by the second filter flows through at least the second vent opening to the suction port of the fan. In the case where the counterflow air passage is at a second angular position, the counterflow air outlet communicates with the first vent opening and is staggered with the second vent opening. In this case, under the suction of the fan, the airflow filtered by the second filter flows through at least the second vent opening to the suction port of the fan, and the air flows backward into the dust collection container through at least the counterflow air passage, the counterflow air outlet, the first vent opening, and the first filter in sequence. In the case where the counterflow air passage is at a third angular position, the counterflow air outlet communicates with the second vent opening and is staggered with the first vent opening. In this case, under the suction of the fan, the airflow filtered by the first filter flows through at least the first vent opening to the suction port of the fan, and the air flows backward into the dust collection container through at least the counterflow air passage, the counterflow air outlet, the second vent opening, and the second filter in sequence. 
     In the switching valve apparatus of this vacuum cleaner, the counterflow air passage rotates to different angular positions relative to the outer casing so that the air passage can be switched more conveniently and efficiently. 
     Optionally, the vacuum cleaner further includes a first chamber, a second chamber, and a third chamber. The outer casing is further provided with a first air outlet located on the outer periphery of the outer casing. The first vent opening faces the first chamber along a radial direction of the outer casing. The second vent opening faces the second chamber along a radial direction of the outer casing. The first air outlet faces the third chamber along a radial direction of the outer casing. In the case where the counterflow air passage is at the first angular position, the first vent opening is communicated between the first chamber and the first air outlet, and the second vent opening is communicated between the second chamber and the first air outlet. In the case where the counterflow air passage is at the second angular position, the first vent opening is communicated between the first chamber and the counterflow air passage, and the second vent opening is communicated between the second chamber and the first air outlet. In the case where the counterflow air passage is at the third angular position, the first vent opening is communicated between the first chamber and the first air outlet, and the second vent opening is communicated between the second chamber and the counterflow air passage. 
     Optionally, the outer casing is further provided with a first cylindrical wall. The first cylindrical wall surrounds the outer periphery of the counterflow air passage, and the first vent opening and the second vent opening are separately disposed on the first cylindrical wall. 
     Optionally, the outer casing is further provided with a first counterflow inlet and a second counterflow inlet. The first counterflow inlet and the second counterflow inlet are separately disposed on the first cylindrical wall. The counterflow air passage is provided with a counterflow air inlet. In the case where the counterflow air passage is at the second angular position, the counterflow air inlet is aligned with and thus communicates with the first counterflow inlet, and the counterflow air outlet is aligned with and thus communicates with the first vent opening. In the case where the counterflow air passage is at the third angular position, the counterflow air inlet is aligned with and thus communicates with the second counterflow inlet, and the counterflow air outlet is aligned with and thus communicates with the second vent opening. 
     Optionally, the vacuum cleaner further includes a tray and a lower cover located on the lower side of the tray. The tray is provided with a first installation through opening penetrating through the upper side of the tray and the lower side of the tray. The first cylindrical wall penetrates through the first installation through opening in the up-and-down direction. The first vent opening and the second vent opening are separately located between the tray and the lower cover. The first counterflow flow air inlet and the second counterflow inlet are separately located on the upper side of the tray. 
     Optionally, the switching valve apparatus further includes a valve core at least partially accommodated in the outer casing and rotatable relative to the outer casing. The counterflow air passage is disposed in the valve core. The valve core is further provided with a second cylindrical wall. The first cylindrical wall is sleeved outside the second cylindrical wall. The counterflow air outlet is disposed on the second cylindrical wall. In the case where the counterflow air passage is at the first angular position, the first cylindrical wall seals the counterflow air outlet. 
     Optionally, the counterflow air passage is further provided with a counterflow air inlet. The counterflow air inlet is disposed on the second cylindrical wall. In the case where the counterflow air passage is at the first angular position, the first cylindrical wall seals the counterflow air inlet. 
     Optionally, the outer casing is further provided with a first counterflow inlet and a second counterflow inlet. The first counterflow inlet and the second counterflow inlet are separately disposed on the first cylindrical wall. In the case where the counterflow air passage is at the second angular position, the counterflow air inlet communicates with the first counterflow inlet, and the second cylindrical wall seals the second counterflow inlet. In the case where the counterflow air passage is at the third angular position, the counterflow air inlet communicates with the second counterflow inlet and the second cylindrical wall seals the first counterflow inlet. 
     Optionally, the second cylindrical wall includes a flexible sealing layer disposed on the outer peripheral surface of the second cylindrical wall. The sealing layer is used for sealing the gap between the inner surface of the first cylindrical wall and the second cylindrical wall. The first cylindrical wall and the second cylindrical wall are disposed coaxially. 
     Optionally, the vacuum cleaner further includes a lower cover. The first vent opening and the second vent opening are separately located on the upper side of the lower cover. The outer casing is fixed relative to the lower cover. The valve core is movable relative to the lower cover. The lower cover blocks upward the lower end of the first cylindrical wall and the lower end of the second cylindrical wall. 
     Optionally, the outer casing is further provided with a first counterflow inlet and a second counterflow inlet. In the case where the counterflow air passage is at the second angular position, the first counterflow inlet communicates with the first vent opening through the counterflow air passage. In the case where the counterflow air passage is at the third angular position, the second counterflow inlet communicates with the second vent opening through the counterflow air passage. 
     Optionally, the counterflow air passage is provided with a counterflow air inlet. The counterflow air inlet forms the air inlet of the counterflow air passage, and the counterflow air outlet forms the air outlet of the counterflow air passage. In the case where the counterflow air passage is at the second angular position, the first counterflow inlet communicates with the counterflow air inlet and the counterflow air outlet communicates with the first vent opening, so that the first counterflow inlet communicates with the first vent opening through the counterflow air passage. In the case where the counterflow air passage is at the third angular position, the second counterflow inlet communicates with the counterflow air inlet and the counterflow air outlet communicates with the second vent opening, so that the second counterflow inlet communicates with the second vent opening through the counterflow air passage. 
     Optionally, in the case where the counterflow air passage is at the second angular position, the first counterflow inlet is aligned with and thus communicates with the counterflow air inlet and the counterflow air outlet is aligned with and thus communicates with the first vent opening. In the case where the counterflow air passage is at the third angular position, the second counterflow inlet is aligned with and thus communicates with the counterflow air inlet and the counterflow air outlet is aligned with and thus communicates with the second vent opening. 
     Optionally, in the case where the counterflow air passage is at the first angular position, the outer casing seals the counterflow air outlet and the counterflow air inlet. In this case, the counterflow air outlet is staggered with the first vent opening and the second vent opening, and the counterflow air inlet is staggered with the first counterflow inlet and the second counterflow inlet. 
     Optionally, in the case where the counterflow air passage is at the first angular position, the first vent opening, the counterflow air outlet, and the second vent opening are arranged in sequence along the circumferential direction of the outer casing, and the first counterflow inlet, the counterflow air inlet, and the second counterflow inlet are arranged in sequence along the circumferential direction of the outer casing. 
     Optionally, the switching valve apparatus further includes a valve core at least partially accommodated in the outer casing and rotatable relative to the outer casing. The counterflow air passage is disposed in the valve core. The counterflow air passage rotates along with the rotation of the valve core. In the case where the counterflow air passage is at the first angular position, the valve core seals the first counterflow inlet and the second counterflow inlet. 
     Optionally, the first vent opening and the second vent opening are arranged side by side along the circumferential direction of the outer casing; the first counterflow inlet and the second counterflow inlet are arranged side by side along the circumferential direction of the outer casing; the first vent opening and the first counterflow inlet are arranged side by side in the height direction of the outer casing; and the second vent opening and the second counterflow inlet are arranged side by side in the height direction of the outer casing. 
     Optionally, the vacuum cleaner further includes a tray, a lower cover located on the lower side of the tray, and an upper cover located on the upper side of the tray. The counterflow air passage is provided with a counterflow air inlet. The first vent opening and the second vent opening are separately located between the tray and the lower cover. The first counterflow inlet and the second counterflow inlet are separately located between the tray and the upper cover. In the case where the counterflow air passage is at the second angular position, at least part of the air discharged by the fan into the space between the tray and the upper cover may flow backward into the dust collection container through at least the first counterflow inlet, the counterflow air inlet, the counterflow air passage, the counterflow air outlet, the first vent opening, and the first filter in sequence. In the case where the counterflow air passage is at the third angular position, at least part of the air discharged by the fan into the space between the tray and the upper cover may flow backward into the dust collection container through at least the second counterflow inlet, the counterflow air inlet, the counterflow air passage, the counterflow air outlet, the second vent opening, and the second filter in sequence. 
     Optionally, the switching valve apparatus further includes a valve core at least partially accommodated in the outer casing and rotatable relative to the outer casing. The valve core is provided with a first blocking wall and a second blocking wall. The first blocking wall and the second blocking wall are located in the outer casing. The counterflow air passage is formed between the first blocking wall and the second blocking wall. The vacuum cleaner further includes a driving motor for driving the valve core to rotate. The valve core is further provided with a center column. The driving motor may drive the center column to rotate to drive the valve core to rotate. The first blocking wall and the second blocking wall are integrated with and separately extend from the center column. 
     Optionally, the outer casing is further provided with a first air outlet. The first vent opening, the second vent opening, and the first air outlet are separately disposed on the outer periphery of the outer casing. In the case where the counterflow air passage is at the first angular position, the first vent opening and the second vent opening separately communicate with the first air outlet. In this case, under the suction of the fan, the airflow filtered by the first filter sequentially flows through at least the first vent opening and the first air outlet to the suction port of the fan, and the airflow filtered by the second filter sequentially flows through at least the second vent opening and the first air outlet to the suction port of the fan. In the case where the counterflow air passage is at the second angular position, the second vent opening communicates with the first air outlet. In this case, under the suction of the fan, the airflow filtered by the second filter sequentially flows through at least the second vent opening and the first air outlet to the suction port of the fan. In the case where the counterflow air passage is at the third angular position, the first vent opening communicates with the first air outlet. In this case, under the suction of the fan, the airflow filtered by the first filter sequentially flows through at least the first vent opening and the first air outlet to the suction port of the fan. The first vent opening, the second vent opening, and the first air outlet are arranged side by side along the circumferential direction of the outer casing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a vacuum cleaner according to the present application; 
         FIG. 2  is an exploded view of the head of the vacuum cleaner (with the filters removed) according to the present application; 
         FIG. 3  is another exploded view of the head of the vacuum cleaner (with the filters removed) according to the present application; 
         FIG. 4  is a schematic view illustrating a separated state of the tray and the lower cover of the vacuum cleaner according to the present application; 
         FIG. 5  is a partially enlarged cross-sectional view of the head of the vacuum cleaner according to the present application (the cross-section is a horizontal plane and the valve core is at the first angular position relative to the outer casing); 
         FIG. 6  is a schematic view illustrating a separated state of the upper cover, the tray, and the lower cover of the vacuum cleaner according to the present application; 
         FIG. 7  is an exploded view of the switching valve apparatus of the vacuum cleaner according to the present application; 
         FIG. 8  is a schematic view illustrating a separated state of the outer casing and the valve core of the vacuum cleaner according to the present application; 
         FIG. 9  is a perspective view of the vacuum cleaner in the case where the switching valve apparatus and the driving motor are assembled according to the present application; 
         FIG. 10  is a top view of the head of the vacuum cleaner (with the housing and the upper cover removed) according to the present application; 
         FIG. 11  is a perspective view of the switching valve apparatus of this vacuum cleaner in the case where the valve core is at the second angular position relative to the outer casing; 
         FIG. 12  is a vertical sectional view of the head of the vacuum cleaner according to the present application (the valve core is at the first angular position relative to the outer casing); 
         FIG. 13  is a perspective view of the switching valve apparatus of this vacuum cleaner in the case where the valve core is at the third angular position relative to the outer casing; 
         FIG. 14  is another vertical sectional view of the head of the vacuum cleaner according to the present application; 
         FIG. 15  is a perspective view of the switching valve apparatus of this vacuum cleaner in the case where the valve core is at the first angular position relative to the outer casing; 
         FIG. 16  is a bottom view of the head of the vacuum cleaner (with the filter and the lower cover removed) according to the present application; 
         FIG. 17  is a partially enlarged cross-sectional view of the head of the vacuum cleaner viewed from the top according to the present application (the cross-section is a horizontal plane and the valve core is at the first angular position relative to the outer casing); and 
         FIG. 18  is an enlarged view of part of the structure in  FIG. 12  (the valve core is at the first angular position relative to the outer casing). 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 to 17 , the vacuum cleaner provided in the present application includes a dust collection container  10 , a fan  11 , a first filter  120 , a second filter  121 , and a switching valve apparatus. 
     The dust collection container  10  is used for accommodating the dust, debris, and other garbage sucked by this vacuum cleaner. The dust collection container  10  is provided with a dirt suction port  100 . The dirt suction port  100  is used for docking with a hose assembly (not shown). The hose assembly may be connected to a suction head (not shown). The garbage enters the dust collection container  10  along with the suction airflow through the suction head, the hose assembly, and the dirt suction port  100 . The capacity of the dust collection container  10  is between 0.5 gallons (1 gallon=3.785412 liters) and 30 gallons and may be between 1 gallon and 20 gallons such as 6 gallons, 9 gallons, 10 gallons, 12 gallons, 14 gallons, and 16 gallons. The fan  11  operates to form the suction airflow. 
     The switching valve apparatus includes an outer casing  2  and a counterflow air passage  30 . The outer casing  2  is provided with a first vent opening  200  corresponding to the first filter  120  and a second vent opening  201  corresponding to the second filter  121 . The counterflow air passage  30  is at least partially located in the outer casing  2  and is rotatable to different angular positions relative to the outer casing  2 . The counterflow air passage  30  is rotatable to different angles relative to the outer casing  2  so that the counterflow air passage  30  may be at different angular positions (for example, a first angular position, a second angular position, or a third angular position) relative to the outer casing  2 . The first angular position, the second angular position, and the third angular position are different angular positions of the counterflow air passage  30  or a valve core  3  (detailed later) relative to the outer casing  2 . In the case where the counterflow air passage  30  is at the first angular position relative to the outer casing  2 , the first vent opening  200  is fluidly communicated between the first filter  120  and the suction port  111  of the fan  11 , and the second vent opening  201  is fluidly communicated between the second filter  121  and the suction port  111  of the fan  11 . In this case, under the suction of the fan  11 , the airflow filtered by the first filter  120  flows through at least the first vent opening  200  to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  flows through at least the second vent opening  201  to the suction port  111  of the fan  11  so that the airflow filtered by the first filter  120  flows through at least the first vent opening  200  during flowing to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  flows through at least the second vent opening  201  during flowing to the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  is at the second angular position relative to the outer casing  2 , the first vent opening  200  is fluidly communicated between the counterflow air passage  30  and the first filter  120 , and the second vent opening  201  is fluidly communicated between the second filter  121  and the suction port  111  of the fan  11 . In this case, under the suction of the fan  11 , the airflow filtered by the second filter  121  flows through at least the second vent opening  201  to the suction port  111  of the fan  11 , and the air flows backward into the dust collection container  10  through at least the counterflow air passage  30 , the first vent opening  200 , and the first filter  120  in sequence, which also means that the air flows through at least the counterflow air passage  30 , the first vent opening  200 , and the first filter  120  during flowing backflow into the dust collection container  10 . In the case where the counterflow air passage  30  is at the third angular position relative to the outer casing  2 , the second vent opening  201  is fluidly communicated between the counterflow air passage  30  and the second filter  121 , and the first vent opening  200  is fluidly communicated between the first filter  120  and the suction port  111  of the fan  11 . In this case, under the suction of the fan  11 , the airflow filtered by the first filter  120  flows through at least the first vent opening  200  to the suction port  111  of the fan  11 , and the air flows backward into the dust collection container  10  through at least the counterflow air passage  30 , the second vent opening  201 , and the second filter  121  in sequence, which also means that the air flows through at least the counterflow air passage  30 , the second vent opening  201 , and the second filter  121  during flowing backward into the dust collection container  10 . 
     The first filter  120  and the second filter  121  are separately detachable. The fan  11  includes an impeller (not shown), a motor  110 , and an impeller housing  112  for shielding the impeller. The impeller is located at the bottom of the motor  110 . The shaft (not shown) of the motor  110  drives the impeller to rotate to generate the suction airflow, and thus drives the dust, debris, and other garbage are sucked into the dust collection container  10 . The rated power of the fan  11  is between 100 W and 3000 W and may be between 200 W and 1800 W such as 960 W, 1200 W, 1320 W, and 1440 W. 
     In this embodiment, the first angular position is a position between the second angular position and the third angular position, and the counterflow air passage  30  is rotatable between the second angular position and the third angular position relative to the outer casing  2 . The counterflow air passage  30  is rotatable from the first angular position to the second angular position relative to the outer casing  2  along a rotation direction, and is rotatable from the second angular position to the third angular position relative to the outer casing  2  against the rotation direction. The counterflow air passage  30  rotates from the second angular position to the third angular position through the first angular position against the rotation direction. The angular difference between the first angular position and the second angular position is a first angle, and the angular difference between the first angular position and the third angular position is a second angle. The counterflow air passage  30  rotates from the first angular position to the second angular position along the rotation direction by the first angle, and the counterflow air passage  30  rotates from the first angular position to the third angular position against the rotation direction by the second angle. The first angle is between 60 degrees and 80 degrees, and the second angle is between 60 degrees and 80 degrees. The first angle is equal to the second angle. In this embodiment, the first angle and the second angle may be 70 degrees, and the counterflow air passage  30  may rotate from the first angular position to the second angular position along the rotation direction by 70 degrees, and may rotate from the second angular position to the third angular position against the rotation direction by 140 degrees. 
     In the case where the counterflow air passage  30  is at the first angular position relative to the outer casing  2 , the outer casing  2  seals the counterflow air passage  30 . The outer casing  2  is further provided with a first counterflow inlet  202  and a second counterflow inlet  203 . In the case where the counterflow air passage  30  is at the second angular position relative to the outer casing  2 , the first vent opening  200  communicates with the first counterflow inlet  202  through the counterflow air passage  30  so that the air can flow into the dust collection container  10  through at least the first counterflow inlet  202 , the counterflow air passage  30 , the first vent opening  200 , and the first filter  120  in sequence. In this case, the second vent opening  201  is staggered with the second counterflow inlet  203  and thus does not communicate with the second counterflow inlet  203 . In the case where the counterflow air passage  30  is at the third angular position relative to the outer casing  2 , the second vent opening  201  communicates with the second counterflow inlet  203  through the counterflow air passage  30  so that the air can flow into the dust collection container  10  through at least the second counterflow inlet  203 , the counterflow air passage  30 , the second vent opening  201 , and the second filter  121  in sequence. In this case, the first vent opening  200  is staggered with the first air counterflow air  202  and thus does not communicate with the first counterflow inlet  202 . The counterflow air passage  30  is provided with a counterflow air outlet  300  and a counterflow air inlet  301 . The counterflow air inlet  301  forms the air inlet of the counterflow air passage  30 , and the counterflow air outlet  300  forms the air outlet of the counterflow air passage  30 . In the case where the counterflow air passage  30  is at the second angular position relative to the outer casing  2 , the counterflow air inlet  301  communicates with the first counterflow inlet  202 , and the counterflow air outlet  300  communicates with the first vent opening  200 . In an embodiment, in the case where the counterflow air passage  30  is at the second angular position relative to the outer casing  2 , the counterflow air inlet  301  is aligned with and thus communicates with the first counterflow inlet  202  and the counterflow air outlet  300  is aligned with and thus communicates with the first vent opening  200 , so that the first counterflow inlet  202  communicates with the first vent opening  200  through the counterflow air passage  30 . In this case, the air flows backward into the dust collection container  10  through at least the first counterflow inlet  202 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the first vent opening  200 , and the first filter  120  in sequence so that a first counterflow airflow is formed. Since the first counterflow airflow flows through the first filter  120  in the reverse direction, the blockages in the first filter  120  can be reduced or cleared. The normal suction work of the vacuum cleaner is that the airflow that carries the dust, debris, and other garbage flows through the filter (the first filter  120  and the second filter  121 ) in the forward direction, the dust, debris, and other garbage are filtered out by the filter and left in the dust collection container  10 . In the case where the counterflow air passage  30  is at the third angular position relative to the outer casing  2 , the counterflow air inlet  301  communicates with the second counterflow inlet  203  and the counterflow air outlet  300  communicates with the second vent opening  201 . In an embodiment, in the case where the counterflow air passage  30  is at the third angular position relative to the outer casing  2 , the counterflow air inlet  301  is aligned with and thus communicates with the second counterflow inlet  203  and the counterflow air outlet  300  is aligned with and thus communicates with the second vent opening  201 , so that the second counterflow inlet  203  communicates with the second vent opening  201  through the counterflow air passage  30 . In this case, the air flows backward into the dust collection container  10  through at least the second counterflow inlet  203 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the second vent opening  201 , and the second filter  121  in sequence so that a second counterflow airflow is formed. Since the second counterflow airflow flows through the second filter  121  in the reverse direction, the blockages in the second filter  121  can be reduced or cleared. The airflow that carries the dust, debris, and other garbage flows through the filter in the forward direction, and thus the filter may be gradually blocked, and the filtration performance may be reduced. The airflow flowing through the filter (the first filter  120  and the second filter  121 ) in the reverse direction is compared with the aforementioned forward direction. The airflow flows through the filter in the reverse direction, and thus the blockages in the filter can be gradually reduced. 
     In the case where the counterflow air passage  30  is at the first angular position relative to the outer casing  2 , the outer casing  2  seals the counterflow air outlet  300  and the counterflow air inlet  301 . In this case, the counterflow air outlet  300  is staggered with the first vent opening  200  and the second vent opening  201 , and the counterflow air inlet  301  is staggered with the first counterflow inlet  202  and the second counterflow inlet  203 . Moreover, in this case, the first vent opening  200 , the counterflow air outlet  300 , and the second vent opening  201  are arranged in sequence along the circumferential direction of the outer casing  2 , and the first counterflow inlet  202 , the counterflow air inlet  301 , and the second counterflow inlet  203  are arranged in sequence along the circumferential direction of the outer casing  2 . The outer casing  2  is further provided with a first air outlet  204 . The first air outlet  204  is used for being fluidly communicated between the first vent opening  200  and the suction port  111  of the fan  11  and for being fluidly communicated between the second vent opening  201  and the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  is at the first angular position, the first air outlet  204  and the counterflow air outlet  300  are located on two opposite sides of the outer casing  2  along the radial direction of the outer casing  2 . 
     The switching valve apparatus further includes a valve core  3 . The valve core  3  is at least partially accommodated in the outer casing  2  and is rotatable relative to the outer casing  2 . The counterflow air passage  30  is disposed in the valve core  3 , and the counterflow air passage  30  is part of the valve core  3 . Since the counterflow air passage  30  is part of the valve core  3 , the counterflow air passage  30  being at the first angular position means that the valve core  3  is at the first angular position, the counterflow air passage  30  being at the second angular position means that the valve core  3  is at the second angular position, and the counterflow air passage  30  being at the third angular position means that the valve core  3  is at the third angular position. The counterflow air passage  30  rotates along with the rotation of the valve core  3 . The valve core  3  rotates to different angles relative to the outer casing  2 , and thus the counterflow air passage  30  is driven to rotate to different angles. Similar to the counterflow air passage  30 , the valve core  3  is rotatable from the first angular position to the second angular position relative to the outer casing  2  and is rotatable back and forth between the second angular position and the third angular position relative to the outer casing  2 . The valve core  3  may rotate from the first angular position to the second angular position along the rotation direction by the first angle, and the valve core  3  may rotate from the first angular position to the third angular position against the rotation direction by the second angle. In the case where the counterflow air passage  30  is at the first angular position, or in the case where the valve core  3  is at the first angular position, the valve core  3  seals the first counterflow inlet  202  and the second counterflow inlet  203 . 
     The first vent opening  200 , the second vent opening  201 , the first counterflow inlet  202 , and the second counterflow inlet  203  are separately located on the outer periphery of the outer casing  2 . The first vent opening  200  and the second vent opening  201  are arranged side by side along the circumferential direction of the outer casing  2 . The first counterflow inlet  202  and the second counterflow inlet  203  are arranged side by side along the circumferential direction of the outer casing  2 . The first vent opening  200  and the first counterflow inlet  202  are arranged side by side in the height direction of the outer casing  2 . The second vent opening  201  and the second counterflow inlet  203  are arranged side by side in the height direction of the outer casing  2 . The outer casing  2  is further provided with a first cylindrical wall  20 . The first cylindrical wall  20  surrounds the outer periphery of the counterflow air passage  30 . The first vent opening  200 , the second vent opening  201 , the first counterflow inlet  202 , the second counterflow inlet  203 , and the first air outlet  204  are separately provided on the first cylindrical wall  20 . The first vent opening  200  and the second vent opening  201  are arranged side by side along the circumferential direction of the first cylindrical wall  20 . The first counterflow inlet  202  and the second counterflow inlet  203  are arranged side by side along the circumferential direction of the first cylindrical wall  20 . The first vent opening  200  and the first counterflow inlet  202  are arranged side by side in the height direction of the first cylindrical wall  20 . The second vent opening  201  and the second counterflow inlet  203  are arranged side by side in the height direction of the first cylindrical wall  20 . The first vent opening  200  and the second vent opening  201  are located at the lower part of the first cylindrical wall  20 , and the first counterflow inlet  202  and the second counterflow inlet  203  are located at the upper part of the first cylindrical wall  20 . In the case where the valve core  3  is at the first angular position, the first air outlet  204  and the counterflow air outlet  300  are located on two opposite sides of the first cylindrical wall  20  along the radial direction of the first cylindrical wall  20 . 
     The vacuum cleaner further includes a tray  4 , a lower cover  5 , and an upper cover  6 . The tray  4  is provided with a first installation through opening  40  penetrating through the upper side of the tray  4  and the lower side of the tray  4 , and the first cylindrical wall  20  penetrates through the first installation through opening  40 . The counterflow air outlet  300 , the first vent opening  200 , and the second vent opening  201  are separately located between the tray  4  and the lower cover  5 . The counterflow air inlet  301 , the first counterflow inlet  202 , and the second counterflow inlet  203  are separately located between the tray  4  and the upper cover  6 . The counterflow air outlet  300 , the first vent opening  200 , and the second vent opening  201  are separately located on the lower side of the tray  4 . The counterflow air inlet  301 , the first counterflow inlet  202 , and the second counterflow inlet  203  are separately located on the upper side of the tray  4 . The upper cover  6  is located on the upper side of the tray  4 , and the lower cover  5  is located on the lower side of the tray  4 . The tray  4  is roughly disc-shaped. The switching valve apparatus is perpendicular to the tray  4 . 
     The first cylindrical wall  20  has a shape of a hollow cylinder. The first cylindrical wall  20  is provided with a ring-shaped flange  205  surrounding the outer periphery of the first cylindrical wall  20 . The first vent opening  200  and the second vent opening  201  are located on the lower side of the ring-shaped flange  205 . The counterflow air inlet  202  and the second counterflow inlet  203  are located on the upper side of the ring-shaped flange  205 . The ring-shaped flange  205  abuts against the periphery of the first installation through opening  40 . The first installation through opening  40  is circular, and the ring-shaped flange  205  is fastened to the tray  4  through screws so that the outer casing  2  is fastened to the tray  4 . The ring-shaped flange  205  may be provided with a ring-shaped rib (not shown). The ring-shaped rib surrounds the outer periphery of the first cylindrical wall  20 . The tray  4  is further provided with a ring-shaped groove (not shown) surrounding the first installation through opening  40 . The ring-shaped rib is embedded in the ring-shaped groove to enhance the positioning between the ring-shaped flange  205  and the tray  4 . The ring-shaped flange  205  is located on the upper side of the tray  4 . The ring-shaped flange  205  protrudes downward and abuts downward against the outer periphery of the first installation through opening  40 . The ring-shaped rib is downwardly embedded in the ring-shaped groove. 
     The upper cover  6  is provided with a second installation through opening  60  penetrating through the upper side of the upper cover  6  and the lower side of the upper cover  6 , and a third installation through opening  61  penetrating through the upper side of the upper cover  6  and the lower side of the upper cover  6 . The first cylindrical wall  20  penetrates through the second installation through opening  60 . The second installation through opening  60  faces downward to the first installation through opening  40 . The first counterflow inlet  202  and the second counterflow inlet  203  are located between the first installation through opening  40  and the second installation through opening  60 . The upper cover  6  is fastened to the tray  4  through screws. The upper part of the fan  11  is exposed outside the third installation through opening  61 . 
     The first cylindrical wall  20  is further provided with a ring-shaped shoulder portion  206 . The first counterflow inlet  202  and the second counterflow inlet  203  are located on the lower side of the ring-shaped shoulder portion  206 . The ring-shaped shoulder portion  206  abuts upward against the periphery of the second installation through opening  60 . The upper cover  6  covers part of the first cylindrical wall  20  between the first installation through opening  40  and the second installation through opening  60 . From another perspective, the upper cover  6  covers part of the first cylindrical wall  20  between the ring-shaped shoulder portion  206  and the ring-shaped flange  205 . The part of the first cylindrical wall  20  located on the upper side of the ring-shaped shoulder portion  206  is exposed outside the second installation through opening  60 . The first counterflow inlet  202  and the second counterflow inlet  203  are located between the ring-shaped shoulder portion  206  and the ring-shaped flange  205 . 
     The valve core  3  is further provided with a second cylindrical wall  31 . The second cylindrical wall  31  surrounds the rotation axis of the valve core  3  (the rotation axis of the valve core  3  is the central axis around which the valve core  3  rotates and is a virtual straight line). The first cylindrical wall  20  and the second cylindrical wall  31  are disposed coaxially. In this embodiment, the extending direction of the rotation axis of the valve core  3 , the axial direction of the first cylindrical wall  20 , and the axial direction of the second cylindrical wall  31  are the up-and-down direction. The first cylindrical wall  20  is sleeved outside the second cylindrical wall  31 , and the counterflow air passage  30  is at least partially located in the second cylindrical wall  31 . The counterflow air outlet  300  and the counterflow air inlet  301  are separately provided on the second cylindrical wall  31 . In the case where the valve core  3  is at the first angular position, the first cylindrical wall  20  seals the counterflow air outlet  300  and the counterflow air inlet  301 . In the case where the valve core  3  is at the second angular position, the second cylindrical wall  31  seals the second counterflow inlet  203 . Moreover, in this case, the counterflow air inlet  301  communicates with the first counterflow inlet  202 , and the counterflow air outlet  300  communicates with the first vent opening  200 . In the case where the valve core  3  is at the third angular position, the second cylindrical wall  31  seals the first counterflow inlet  202 . Moreover, in this case, the counterflow air inlet  301  communicates with the second counterflow inlet  203 , and the counterflow air outlet  300  communicates with the second vent opening  201 . In this embodiment, the rotation axis of the motor  110  extends in the up-and-down direction, the rotation axis of the fan  11  is parallel to the rotation axis of the valve core  3 , and the shaft of the motor  110  is parallel to the center column  32  of the valve core  3 . 
     The second cylindrical wall  31  includes a flexible sealing layer  310  disposed on the outer peripheral surface of the second cylindrical wall  31  and a partition  31 . The sealing layer  310  seals the gap between the inner surface of the first cylindrical wall  20  and the second cylindrical wall  31  to achieve the necessary seal between the first cylindrical wall  20  and the second cylindrical wall  31 . In this embodiment, the sealing layer  310  is pasted on the outer peripheral surface of the second cylindrical wall  31  and thus may be considered as part of the second cylindrical wall  31 , and the sealing layer  310  rotates with the second cylindrical wall  31 . The sealing layer  310  may be made of PU material (that is, polyurethane material) or EVA material (that is, ethylene-vinyl acetate copolymer material). The partition  311  separates the counterflow air outlet  300  and the counterflow air inlet  301  in the up-and-down direction. Part of the sealing layer  310  is attached to the outer surface of the partition  311  to achieve the necessary seal between the partition  311  and the first cylindrical wall  20 . 
     The valve core  3  is further provided with a center column  32 , a first blocking wall  33 , a second blocking wall  34 , and a first end wall  35 . The first blocking wall  33  and the second blocking wall  34  separately extend from the center column  32  to the second cylindrical wall  31 , and the counterflow air passage  30  is formed between the first blocking wall  33  and the second blocking wall  34 . The first end wall  35  is connected to the upper end of the second cylindrical wall  31 . The upper end of the first blocking wall  33  and the upper end of the second blocking wall  34  are separately integrally connected to the first end wall  35 . The first end wall  35  is perpendicular to the rotation axis of the valve core  3 . The counterflow air inlet  301  is located between the counterflow air outlet  300  and the first end wall  35 , and the first end wall  35  is roughly a circular plate. 
     The first vent opening  200  and the second vent opening  201  are separately located on the upper side of the lower cover  5 . The first filter  120  and the second filter  121  are separately located on the lower side of the lower cover  5  and installed to the lower cover  5 . The lower cover  5  is further provided with a sealing gasket  50 , a ring-shaped positioning groove  51 , and a matching portion  52 . The sealing gasket  50  blocks upward the lower end of the first cylindrical wall  20  and the lower end of the second cylindrical wall  31  to achieve the sealing between the lower end of the first cylindrical wall  20  and the lower cover  5  and between the lower end of the second cylindrical wall  31  and the lower cover  5 . The first blocking wall  33  and the second blocking wall  34  separately abut downward against the sealing gasket  50 . The sealing gasket  50  blocks the lower end of the counterflow air passage  30 , and the first end wall  35  blocks the upper end of the counterflow air passage  30 ; the first blocking wall  33  and the second blocking wall  34  separately extend downward from the first end wall  35  to the lower cover  5 . In an embodiment, the first blocking wall  33  and the second blocking wall  34  separately extend downward from the first end wall  35  to the sealing gasket  50  of the lower cover  5 . 
     The sealing gasket  50  is disc-shaped, the ring-shaped positioning groove  51  surrounds the outer periphery of the sealing gasket  50 , and the lower end of the first cylindrical wall  20  is embedded in the ring-shaped positioning groove  51 . The center opening of the sealing gasket  50  allows the matching portion  52  to penetrate upward, and the matching portion  52  protrudes upward from the sealing gasket  50  and is embedded in the lower end of the center column  32 . The lower end of the center column  32  abuts downward against the sealing gasket  50 . In this embodiment, the sealing gasket  50  and the sealing layer  310  are glued and fixed. Similar to the sealing layer  310 , the sealing gasket  50  may also be made of PU material or EVA material. The lower cover  5  is further provided with a ring-shaped convex rib  53 . The ring-shaped convex rib  53  surrounds the sealing gasket  50 . The outer periphery of the sealing gasket  50  abuts on the inner periphery of the ring-shaped convex rib  53 . The ring-shaped convex rib  53  is located in the lower end of the first cylindrical wall  20 . The ring-shaped convex rib  53  forms the inner groove wall of the ring-shaped positioning groove  51 . 
     The lower cover  5  is further provided with a disc portion  58 . The ring-shaped positioning groove  51 , the matching portion  52 , the ring-shaped convex rib  53 , and the sealing gasket  50  are separately disposed on the disc portion  58  to form part of the disc portion  58 . The lower cover  5  blocks upward the lower end of the first cylindrical wall  20  and the lower end of the second cylindrical wall  31  through the disc portion  58 . The disc portion  58  protrudes downward from the bottom surface of the lower cover  5 . The disc portion  58  is further provided with a ring-shaped peripheral wall  54  located on the outer periphery of the disc portion  58 . The ring-shaped peripheral wall  54  surrounds the outer periphery of the ring-shaped convex rib  53 . The gap between the ring-shaped peripheral wall  54  and the ring-shaped convex rib  53  forms the ring-shaped positioning groove  51 . The ring-shaped peripheral wall  54  forms the outer groove wall of the ring-shaped positioning groove  51 . The ring-shaped convex rib  53  forms the inner groove wall of the ring-shaped positioning groove  51 . In this embodiment, the outer casing  2  is fixed relative to the lower cover  5 , and the valve core  3  is movable relative to the lower cover  5 . The valve core  3  is located above the disc portion  58  of the lower cover  5  and rotates between the first angular position and the second angular position. 
     The air sucked by the fan  11  from the dust collection container  10  is discharged into a space between the tray  4  and the upper cover  6 . In the case where the counterflow air passage  30  is at the second angular position relative to the outer casing  2 , at least part of the air discharged by the fan  11  into the space between the tray  4  and the upper cover  6  may flow backward into the dust collection container  10  through at least the first counterflow inlet  202 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the first vent opening  200 , and the first filter  120  in sequence. In the case where the counterflow air passage  30  is at the third angular position relative to the outer casing  2 , at least part of the air discharged by the fan  11  into the space between the tray  4  and the upper cover  6  may flow backward into the dust collection container  10  through at least the second counterflow inlet  203 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the second vent opening  201 , and the second filter  121  in sequence. 
     The length direction of the center column  32  is parallel to the rotation axis of the valve core  3 . The center column  32  extends downward to the lower cover  5 . The valve core  3  rotates above the lower cover  5  with the center column  32  as an axis, and the center column  32  forms the shaft of the valve core  3 . The lower end of the center column  32  is embedded in the matching portion  52  or the matching portion  52  is embedded in the lower end of the center column  32 . In this embodiment, the matching portion  52  is a convex portion protruding upward and embedded in the lower end of the center column  32 ; the matching portion  52  may also be disposed as a groove so that the lower end of the center column  32  is inserted into the matching portion  52  which is a groove. The first blocking wall  33  and the second blocking wall  34  are located in the outer casing  2 . The first blocking wall  33  is opposite to the second blocking wall  34  along the circumferential direction surrounding the rotation axis of the valve core  3 . The first blocking wall  33  and the second blocking wall  34  form an included angle. The cross-section of the counterflow air passage  30  is roughly fan-shaped. The first blocking wall  33  and the second blocking wall  34  extend radially from the center column  32  separately. The first blocking wall  33  and the second blocking wall  34  each are an elongated shape extending in the length direction of the center column  32 . The first blocking wall  33  is provided with a first side facing away from the center column  32 , and the second blocking wall  34  is provided with a second side facing away from the center column  32 . The first side and the second side separately extend in a direction parallel to the length direction of the center column  32 . The counterflow air outlet  300  and the counterflow air inlet  301  are separately located between the first side and the second side, and the counterflow air outlet  300  and the counterflow air inlet  301  are arranged in a direction parallel to the length direction of the center column  32 . In this embodiment, the length direction of the center column  32  is the up-and-down direction, so the counterflow air outlet  300  and the counterflow air inlet  301  are arranged in the up-and-down direction. The first side and the second side are separately located on the second cylindrical wall  31 , and the first side and the second side separately extend in the height direction of the second cylindrical wall  31 . 
     The vacuum cleaner further includes a driving motor  14  for driving the valve core  3  to rotate. The shaft (not shown) of the driving motor  14  drives the center column  32  to rotate so as to drive the valve core  3  to rotate. The driving motor  14  is located above the first end wall  35 . The center column  32  is integrally connected to the first end wall  35 . The center column  32  is provided with a matching end  320  extending beyond the first end wall  35  and abutting against the shaft of the driving motor  14 . Multiple first teeth (not shown) are disposed inside the matching end  320 , and multiple second teeth (not shown) are disposed on the outer periphery of the shaft of the driving motor  14 . The shaft of the driving motor  14  is inserted into the matching end  320  and the first teeth mesh with the second teeth so that the matching end  320  is drivingly connected to the shaft of the driving motor  14 . The driving motor  14  is fixed on the top of the outer casing  2 . 
     The outer casing  2  is further provided with a second end wall  21  and a cavity  22 . The cavity  22  is recessed from the second end wall  21  toward the first end wall  35 . The driving motor  14  is installed and fixed to the outer casing  2  and is at least partially accommodated in the cavity  22 . The matching end  320  extends into the cavity  22 . The second end wall  21  is located above the first end wall  35 , and the matching end  320  extends upward into the cavity  22 . The second end wall  21  is roughly disc-shaped, and the first cylindrical wall  20  extends downward from the periphery of the second end wall  21 . 
     Based on the counterflow air passage  30  or the valve core  3  rotating to different angular positions relative to the outer casing  2 , the counterflow air passage  30  may selectively communicate with or not communicate with the first vent opening  200  and may selectively communicate with or not communicate with the second vent opening  201 . In an embodiment, the counterflow air passage  30  selectively communicates with the first vent opening  200  or communicates with the second vent opening  201 , or does not communicate with the first vent opening  200  and the second vent opening  201 . The first vent opening  200  may selectively or alternatively communicate with the first air outlet  204  and the counterflow air passage  30 , and the second vent opening  201  may selectively or alternatively communicate with the first air outlet  204  and the counterflow air passage  30 . 
     In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, the first vent opening  200  and the second vent opening  201  separately communicate with the first air outlet  204 . In the case where the counterflow air passage  30  or the valve core  3  is at the second angular position, the first vent opening  200  communicates with the counterflow air passage  30 , and the second vent opening  201  communicates with the first air outlet  204 . In the case where the counterflow air passage  30  is at the third angular position relative to the outer casing  2 , the first vent opening  200  communicates with the first air outlet  204 , and the second vent opening  201  communicates with the counterflow air passage  30 . In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, under the suction of the fan  11 , the airflow filtered by the first filter  120  sequentially flows through at least the first vent opening  200  and the first air outlet  204  to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  sequentially flows through at least the second vent opening  201  and the first air outlet  204  to the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  or the valve core  3  is at the second angular position relative to the outer casing  2 , under the suction of the fan  11 , the airflow filtered by the second filter  121  sequentially flows through at least the second vent opening  201  and the first air outlet  204  to the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  or the valve core  3  is at the third angular position relative to the outer casing  2 , under the suction of the fan  11 , the airflow filtered by the first filter  120  sequentially flows through at least the first vent opening  200  and the first air outlet  204  to the suction port  111  of the fan  11 . The first vent opening  200 , the second vent opening  201 , and the first air outlet  204  are arranged side by side along the circumferential direction of the outer casing  2 . Optionally, the first vent opening  200 , the second vent opening  201 , and the first air outlet  204  are arranged side by side along the circumferential direction of the first cylindrical wall  20 , and the first vent opening  200 , the second vent opening  201 , and the first air outlet  204  are at the same height. 
     The vacuum cleaner further includes a first chamber  15 , a second chamber  16 , and a third chamber  17 . The first chamber  15 , the second chamber  16 , and the third chamber  17  are separately adjacent to the outer casing  2 . The first chamber  15 , the second chamber  16 , and the third chamber  17  are formed by the space between the tray  4  and the lower cover  5 . The first vent opening  200  faces the first chamber  15 , and the second vent opening  201  faces the second chamber  16 . In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, under the suction of the fan  11 , the airflow filtered by the first filter  120  sequentially flows through at least the first chamber  15 , the first vent opening  200 , and the third chamber  17  to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  sequentially flows through at least the second chamber  16 , the second vent opening  201 , and the third chamber  17  to the suction port  111  of the fan  11 . Optionally, the first vent opening  200  faces the first chamber  15  along the radial direction of the first cylindrical wall  20 , and the second vent opening  201  faces the second chamber  16  along the radial direction of the first cylindrical wall  20 . 
     The lower cover  5  is further provided with a first vent port  55  and a second vent port  56 . The first vent port  55  is used for fluidly communicating with the first filter  120  and the first chamber  15 , and the second vent port  56  is used for fluidly communicating with the second filter  121  and the second chamber  16 . In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, the airflow filtered by the first filter  120  sequentially flows through at least the first vent port  55 , the first chamber  15 , the first vent opening  200 , and the third chamber  17  to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  sequentially flows through at least the second vent port  56 , the second chamber  16 , the second vent opening  201 , and the third chamber  17  to the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  or the valve core  3  is at the second angular position, under the suction of the fan  11 , the airflow filtered by the second filter  121  sequentially flows through at least the second vent port  56 , the second chamber  16 , the second vent opening  201 , and the third chamber  17  to the suction port  111  of the fan  11 , and the air sequentially flows backward into the dust collection container  10  through at least the counterflow air passage  30 , the first vent opening  200 , the first chamber  15 , the first vent port  55 , and the first filter  120  in sequence. In the case where the counterflow air passage  30  or the valve core  3  is at the third angular position relative to the outer casing  2 , under the suction of the fan  11 , the airflow filtered by the first filter  120  sequentially flows through at least the first vent port  55 , the first chamber  15 , the first vent opening  200 , and the third chamber  17  to the suction port  111  of the fan  11 , and the air flows backward into the dust collection container  10  through at least the counterflow air passage  30 , the second vent opening  201 , the second chamber  16 , the second vent port  56 , and the second filter  121  in sequence. 
     The first vent port  55  and the second vent port  56  separately protrude downward from the bottom surface of the lower cover  5 , the first filter  120  is connected to the first vent port  55 , the second filter  121  is connected to the second vent port  56 , the first vent port  55  is located on the lower side of the first chamber  15  and on the upper side of the first filter  120 , and the second vent port  56  is located on the lower side of the second chamber  16  and on the upper side of the second filter  121 . The first filter  120  and the second filter  121  are cylindrical filters, the upper end of the first filter  120  is sleeved on the first vent port  55 , and the upper end of the second filter  121  is sleeved on the second vent port  56 . 
     The first vent opening  200  is open to the first chamber  15 , the second vent opening  201  is open to the second chamber  16 , and the first air outlet  204  is open to the third chamber  17 . The first vent opening  200  and the first air outlet  204  are used for fluidly communicating the first chamber  15  with the third chamber  17 , and the second vent opening  201  and the first air outlet  204  are used for fluidly communicating the second chamber  16  with the third chamber  17 . The third chamber  17  is located upstream of the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, the fan  11  sucks the third chamber  17  so that the air in the first chamber  15  and the air in the second chamber  16  flow into the third chamber  17 . The first vent opening  200  may form the air inlet of the first chamber  15  and may also form the air outlet of the first chamber  15 . The first vent port  55  may form the air inlet of the first chamber  15  and may also form the air outlet of the first chamber  15 . The second vent opening  201  may form the air inlet of the second chamber  16  and may also form the air outlet of the second chamber  16 . The second vent port  56  may form the air inlet of the second chamber  16  and may also form the air outlet of the second chamber  16 . The first vent port  55  may form the air inlet of the inner cavity  1200  of the first filter  120  and may also form the air outlet of the inner cavity  1200  of the first filter  120 . The second vent port  56  may form the air inlet of the inner cavity  1210  of the second filter  121  and may also form the air outlet of the inner cavity  1210  of the second filter  121 . The inner cavity  1200  of the first filter  120  accommodates a first float  18  for correspondingly blocking the first vent port  55 , and the inner cavity  1210  of the second filter  121  accommodates a second float (not shown) for correspondingly blocking the second vent port  56 . The first float  18  and the second float can float up along with the rise of the liquid level in the dust collection container  10 . In the case where the first float  18  rises to the first vent port  55 , the first vent port  55  is blocked, and in the case where the second float rises to the second vent port  56 , the second vent port  56  is blocked, thereby preventing the liquid in the dust collection container  10  from being sucked from the first vent port  55  and the second vent port  56 . The first float  18  and the second float are, for example, float balls. 
     The first air outlet  204  faces the third chamber  17 . In an embodiment, the first air outlet  204  faces the third chamber  17  along the radial direction of the first cylindrical wall  20 . In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, under the suction of the fan  11 , the airflow filtered by the first filter  120  sequentially flows through at least the first chamber  15 , the first vent opening  200 , the first air outlet  204 , and the third chamber  17  to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  sequentially flows through at least the second chamber  16 , the second vent opening  201 , the first air outlet  204 , and the third chamber  17  to the suction port  111  of the fan  11 . In the case where the counterflow air passage  30  or the valve core  3  is at the second angular position, the second filter  121  fluidly communicates with the suction port  111  of the fan  11  through at least the second chamber  16 , the second vent opening  201 , the first air outlet  204 , and the third chamber  17  in sequence, and the counterflow air passage  30  fluidly communicates with the first filter  120  through at least the first vent opening  200  and the first chamber  15  in sequence. Therefore, in this case, the air may flow through the first filter  120  in the reverse direction after sequentially flowing through at least the counterflow air passage  30 , the first vent opening  200 , and the first chamber  15  so that the blockage in the first filter  120  can be effectively reduced and the cleaning of the first filter  120  can be achieved. In the case where the counterflow air passage  30  or the valve core  3  is at the third angular position, the first filter  120  fluidly communicates with the suction port  111  of the fan  11  through at least the first chamber  15 , the first vent opening  200 , the first air outlet  204 , and the third chamber  17  in sequence, and the counterflow air passage  30  fluidly communicates with the second filter  121  through at least the second vent opening  201  and the second chamber  16  in sequence. In this case, the air may flow through the second filter  121  in the reverse direction after sequentially flowing through the counterflow air passage  30 , the second vent opening  201 , and the second chamber  16  so that the blockage in the second filter  121  can be effectively reduced and the cleaning of the second filter  121  can be achieved. 
     The vacuum cleaner further includes a first partition wall  71  for isolating the first chamber  15  and the third chamber  17 , a second partition wall  72  for isolating the second chamber  16  and the third chamber  17 , and a third partition wall  73  for isolating the first chamber  15  and the second chamber  16 . The first partition wall  71 , the second partition wall  72 , and the third partition wall  73  are separately located between the tray  4  and the lower cover  5 . The third chamber  17  is located between the first chamber  15  and the second chamber  16 , and the third chamber  17  is located between the first partition wall  71  and the second partition wall  72 . The first partition wall  71  has an inner end  710  that abuts on the outer casing  2  and an outer end  711  that abuts on a ring-shaped enclosure (detailed later). The second partition wall  72  has an inner end  720  that abuts on the outer casing  2  and an outer end  721  that abuts on the ring-shaped enclosure. The third partition wall  73  has an inner end  730  that abuts the outer casing  2  and an outer end  731  that abuts on the ring-shaped enclosure. The first air outlet  204  is located between the inner end  710  of the first partition wall  71  and the inner end  720  of the second partition wall  72 . The first vent opening  200  is located between the inner end  710  of the first partition wall  71  and the inner end  730  of the third partition wall  73 . The second vent opening  201  is located between the inner end  720  of the second partition wall  72  and the inner end  730  of the third partition wall  73 . The inner end  710  of the first partition wall  71 , the inner end  720  of the second partition wall  72 , and the inner end  730  of the third partition wall  73  are arranged side by side along the circumferential direction of the outer casing  2 ; optionally, the inner end  710  of the first partition wall  71 , the inner end  720  of the second partition wall  72 , and the inner end  730  of the third partition wall  73  are arranged side by side along the circumferential direction of the first cylindrical wall  20 . The inner end  730  of the third partition wall  73  and the first air outlet  204  are located on two opposite sides of the outer casing  2  along the radial direction of the outer casing  2 ; optionally, the inner end  730  of the third partition wall  73  and the first air outlet  204  are located on two opposite sides of the first cylindrical wall  20  along the radial direction of the first cylindrical wall  20 . The lower edge of the first partition wall  71  is downwardly embedded in a first matching groove  570  on the lower cover  5 , the lower edge of the second partition wall  72  is downwardly embedded in a second matching groove  571  on the lower cover  5 , and the lower edge of the third partition wall  73  is downwardly embedded in a third matching groove  572  on the lower cover  5 . In this embodiment, the upper edge of the first partition wall  71 , the upper edge of the second partition wall  72 , the upper edge of the third partition wall  73 , and the upper edge of the ring-shaped enclosure are separately integrally connected to the tray  4 . 
     The tray  4  is further provided with a second air outlet  42  corresponding to the suction port  111  of the fan  11 . The second air outlet  42  faces upward the suction port  111  of the fan  11  and faces downward the third chamber  17 . The second air outlet  42  is located on the top of the third chamber  17  and between the first partition wall  71  and the second partition wall  72 . The outer casing  2  is located between the first chamber  15 , the second chamber  16 , and the third chamber  17 . The second air outlet  42  forms the air outlet of the third chamber  17 , and the first air outlet  204  forms the air inlet of the third chamber  17 . The first air outlet  204  is roughly located between the suction port  111  of the motor  110  and the third partition wall  73  along the radial direction of the outer casing  2 . The inner end  710  of the first partition wall  71  is provided with a first longitudinal groove, the inner end  720  of the second partition wall  72  is provided with a second longitudinal groove, and the inner end  730  of the third partition wall  73  is provided with a third longitudinal groove. The first cylindrical wall  20  is provided with a first longitudinal rib  207 , a second longitudinal rib  208 , and a third longitudinal rib  209 . The first longitudinal rib  207  is embedded in the first longitudinal groove, the second longitudinal rib  208  is embedded in the second longitudinal groove, and the third longitudinal rib  209  is embedded in the third longitudinal groove so that the first cylindrical wall  20  can be positioned more stably. The first air outlet  204  is located between the first longitudinal rib  207  and the second longitudinal rib  208 , the first vent opening  200  is located between the first longitudinal rib  207  and the third longitudinal rib  209 , and the second vent opening  201  is located between the second longitudinal rib  208  and the third longitudinal rib  209 . The first longitudinal rib  207 , the second longitudinal rib  208 , the third longitudinal rib  209 , the first longitudinal groove, the second longitudinal groove, and the third longitudinal groove separately extend in the height direction of the first cylindrical wall  20 . 
     The ring-shaped enclosure is disposed between the tray  4  and the lower cover  5 , and the ring-shaped enclosure is ring-shaped. The first chamber  15 , the second chamber  16 , and the third chamber  17  are distributed in the area defined by the ring-shaped enclosure, and the ring-shaped enclosure surrounds the outer periphery of the outer casing  2  and is spaced apart from the outer casing  2 . The first partition wall  71 , the second partition wall  72 , and the third partition wall  73  are separately connected between the outer casing  2  and the ring-shaped enclosure. The first partition wall  71 , the second partition wall  72 , and the third partition wall  73  are separately in the shape of a straight bar extending between the outer casing  2  and the ring-shaped enclosure. The area jointly enclosed by the first part  740  of the ring-shaped enclosure, the first partition wall  71 , part of the first cylindrical wall  20  located between the first longitudinal rib  207  and the third longitudinal rib  209 , and the third partition wall  73  forms the first chamber  15 . The area jointly enclosed by the second part  741  of the ring-shaped enclosure, the second partition wall  72 , part of the first cylindrical wall  20  located between the second longitudinal rib  208  and the third longitudinal rib  209 , and the third partition wall  73  forms the second chamber  16 . The area jointly enclosed by the third part  742  of the ring-shaped enclosure, the second partition wall  72 , part of the first cylindrical wall  20  located between the first longitudinal rib  207  and the second longitudinal rib  208 , and the first partition wall  71  forms the third chamber  17 . The first part  740  and the second part  741  are separately C-shaped, and the third part  742  is connected between the first part  740  and the second part  741 . The first part  740 , the second part  741 , and the third part  742  are connected to form a ring. The first part  740  connects the outer end  711  of the first partition wall  71  and the outer end  731  of the third partition wall  73 , the second part  741  connects the outer end  721  of the second partition wall  72  and the outer end  731  of the third partition wall  73 , and the third part  742  connects the outer end  711  of the first partition wall  71  and the outer end  721  of the second partition wall  72 . 
     The vacuum cleaner further includes a fourth chamber  19  and an air discharging port  80  connecting the outside of the vacuum cleaner and the fourth chamber  19 . The fourth chamber  19  is formed between the upper cover  6  and the tray  4 . The upper cover  6  and the lower cover  5  are separately fastened to the tray  4  through screws. The outer casing  2  is partially accommodated in the fourth chamber  19 , and the fan  11  is located in the fourth chamber  19 . The first counterflow inlet  202  and the second counterflow inlet  203  are separately located in the fourth chamber  19 . The air sucked in by the suction port  111  of the fan  11  is discharged into the fourth chamber  19 , and the air discharged into the fourth chamber  19  by the fan  11  is discharged out of the vacuum cleaner through the air discharging port  80 . In the case where the counterflow air passage  30  or the valve core  3  is at the second angular position, part of the air discharged into the fourth chamber  19  by the fan  11  flows backward into the dust collection container  10  through at least the first counterflow inlet  202 , the counterflow air passage  30 , the first vent opening  200 , and the first filter  120  in sequence. Moreover, in this case, another part of the air discharged into the fourth chamber  19  by the fan  11  is discharged out of the vacuum cleaner through the air discharging port  80 . In the case where the counterflow air passage  30  or the valve core  3  is at the third angular position, part of the air discharged into the fourth chamber  19  by the fan  11  flows backward into the dust collection container  10  through at least the second counterflow inlet  203 , the counterflow air passage  30 , the second vent opening  201 , and the second filter  121  in sequence. Moreover, in this case, another part of the air discharged into the fourth chamber  19  by the fan  11  is discharged out of the vacuum cleaner through the air discharging port  80 . 
     In this embodiment, the air discharged by the fan  11  forms the air source of the counterflow air passage  30 . The outer casing  2  may also be disposed to be located at other positions so that the first counterflow inlet  202  and the second counterflow inlet  203  are located outside the fourth chamber  19  (for example, the first counterflow inlet  202  and the second counterflow inlet  203  are located between the housing  81  and the upper cover  6 ), and an opening is disposed on the housing  81  so that the air outside the vacuum cleaner can be directly introduced and supplied to the first counterflow inlet  202  and the second counterflow inlet  203 . The fourth chamber  19  is provided with a first air guiding channel  190  for guiding air toward the air discharging port  80  and a second air guiding channel  191  for guiding air toward the air discharging port  80 . The first air guiding channel  190  and the second air guiding channel  191  are arc-shaped. The first counterflow inlet  202  and the second counterflow inlet  203  are located in the first air guiding channel  190 . The first air guiding channel  190  is surrounded by multiple arc-shaped baffles  192  in the fourth chamber  19 . The vacuum cleaner is further provided with a silencer sponge  82 , and the silencer sponge  82  is located in the fourth chamber  19  and enclosed in a circle. 
     To sum up, in the case where the valve core  3  or the counterflow air passage  30  is at the first angular position, the first vent opening  200 , the second vent opening  201 , and the counterflow air passage  30  are all blocked, and under the suction of the fan  11 , the dust, debris, and other garbage along with the air enter the dust collection container  10  from the suction port  100 . Part of the air entering the dust collection container  10  is filtered by the first filter  120 , sequentially flows through the first vent port  55 , the first chamber  15 , the first vent opening  200 , the first air outlet  204 , the third chamber  17 , the second air outlet  42 , and the suction port  111  of the fan  11 , and is discharged into the fourth chamber  19  and then discharged out of the vacuum cleaner through the air discharging port  80 . Another part of the air entering the dust collection container  10  is filtered by the second filter  121 , sequentially flows through the second vent port  56 , the second chamber  16 , the second vent opening  201 , the first air outlet  204 , the third chamber  17 , the second air outlet  42 , and the suction port  111  of the fan  11 , and is discharged into the fourth chamber  19  and then discharged out of the vacuum cleaner through the air discharging port  80 . 
     In the case where the valve core  3  or the counterflow air passage  30  is at the second angular position, the counterflow air inlet  301  is aligned with the first counterflow inlet  202  and the counterflow air outlet  300  is aligned with the first vent opening  200 , so that the first counterflow inlet  202  communicates with the first vent opening  200 . In this case, under the suction of the fan  11 , the air filtered by the second filter  121  sequentially flows through the second vent port  56 , the second chamber  16 , the second vent opening  201 , the first air outlet  204 , the third chamber  17 , the second air outlet  42 , and the suction port  111  of the fan  11  and is discharged into the fourth chamber  19 . Moreover, part of the air discharged into the fourth chamber  19  flows backward into the dust collection container  10  through the first counterflow inlet  202 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the first vent opening  200 , the first chamber  15 , the first vent port  55 , and the first filter  120  in sequence, and in this process, the air flows through the first filter  120  in the reverse direction, thereby cleaning the first filter  120 . 
     In the case where the valve core  3  or the counterflow air passage  30  is at the third angular position, the counterflow air inlet  301  is aligned with the second counterflow inlet  203 , and the counterflow air outlet  300  is aligned with the second vent opening  201 , so that the counterflow air inlet  301  communicates with the second vent opening  201 . In this case, under the suction of the fan  11 , the air filtered by the first filter  120  sequentially flows through the first vent port  56 , the first chamber  15 , the first vent opening  200 , the first air outlet  204 , the third chamber  17 , the second air outlet  42 , and the suction port  111  of the fan  11  and is discharged into the fourth chamber  19 . Moreover, part of the air discharged into the fourth chamber  19  flows backward into the dust collection container  10  through the second counterflow inlet  203 , the counterflow air outlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the second vent opening  201 , the first chamber  15 , the second vent port  56 , and the second filter  121  in sequence, and in this process, the air flows through the second filter  121  in the reverse direction, thereby cleaning the second filter  121 . 
     For this vacuum cleaner, the fan  11 , the first filter  120 , the second filter  121 , the tray  4 , the upper cover  6 , the lower cover  5 , the housing  81 , the switching valve apparatus, and the driving motor  14  are separately part of the head  83  of this vacuum cleaner. The head  83  is detachably installed in the dust collection container  10 . The first filter  120  and the second filter  121  are located at the bottom of the head  83  and in the dust collection container  10 . The fan  11 , the switching valve apparatus, and the driving motor  14  are separately located inside the head  83 . The head  83  is detachably installed to the upper end of the dust collection container  10  through a buckle  86 . The head  83  may be detached from the upper end of the dust collection container  10  as a whole. The head  83  is provided with a handle  84 , and the handle  84  is used for moving this vacuum cleaner. The bottom of the vacuum cleaner is further provided with multiple wheels  85  for moving this vacuum cleaner. 
     In the case where this vacuum cleaner is stopped, the valve core  3  remains at the first angular position. After this vacuum cleaner is turned on, the fan  11  may start to run to form the suction airflow. Under the driving of the driving motor  14 , the valve core  3  first rotates from the first angular position to the second angular position along the rotation direction and remains at the second angular position for n seconds (n may be 2 seconds), thereby completing the cleaning of the first filter  120  once; and then the valve core  3  rotates from the second angular position to the third angular position against the rotation direction and remains at the third angular position for n seconds, thereby completing the cleaning of the second filter  121  once; and then the valve core  3  rotates from the third angular position to the second angular position along the rotation direction and remains at the second angular position for n seconds. The valve core  3  may remain at the second angular position and the third angular position for multiple rounds so that the first filter  120  and the second filter  121  can be cleaned many times. After the cleaning of the first filter  120  and the second filter  121  is completed, the valve core  3  returns to the first angular position, and then the fan  11  performs normal suction work. 
     In the case where the valve core  3  or the counterflow air passage  30  is at the first angular position, a first forward air passage is formed between the first filter  120  and the suction port  111  of the fan  11 , and a second forward air passage is formed between the second filter  120  and the suction port  111  of the fan  11 . The first forward air passage sequentially passes through the first vent port  55 , the first chamber  15 , the first vent opening  200 , the first air outlet  204 , the third chamber  17 , and the second air outlet  42 , and the first forward air passage passes from the first filter  120  through the first vent port  55 , the first chamber  15 , the first vent opening  200 , the first air outlet  204 , the third chamber  17 , and the second air outlet  42  in sequence to the suction port  111  of the fan  11 . The second forward air passage sequentially passes through the second vent port  56 , the second chamber  16 , the second vent opening  201 , the first air outlet  204 , the third chamber  17 , and the second air outlet  42 , and the second forward air passage passes from the second filter  121  through the second vent port  56 , the second chamber  16 , the second vent opening  201 , the first air outlet  204 , the third chamber  17 , and the second air outlet  42  in sequence to the suction port  111  of the fan  11 . The airflow filtered by the first filter  120  flows along the first forward air passage to the suction port  111  of the fan  11 , and the airflow filtered by the second filter  121  flows along the second forward air passage to the suction port  111  of the fan  11 . 
     In the case where the valve core  3  or the counterflow air passage  30  is switched to the second angular position, a first reverse air passage is formed between the first filter  120  and the first counterflow inlet  202 , and the second filter  120  fluidly communicates with the suction port  111  of the fan  11  still through the aforementioned second forward air passage. In this case, the airflow filtered by the second filter  121  flows along the second forward air passage to the suction port  111  of the fan  11 . The first reverse air passage passes through the counterflow air passage  30  and the first vent opening  200 . In an embodiment, the first reverse air passage sequentially passes through the first counterflow inlet  202 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the first vent opening  200 , the first chamber  15 , and the first vent port  55 . The first reverse air passage passes from the first counterflow inlet  202  through the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the first vent opening  200 , the first chamber  15 , and the first vent port  55  in sequence to the first filter  120 . 
     In the case where the valve core  3  or the counterflow air passage  30  is at the third angular position, a second reverse air passage is formed between the second filter  120  and the second counterflow inlet  203 , and the first filter  120  fluidly communicates with the suction port  111  of the fan  11  still through the aforementioned first forward air passage. In this case, the airflow filtered by the first filter  120  flows along the first forward air passage to the suction port  111  of the fan  11 . The second reverse air passage passes through the counterflow air passage  30  and the second vent opening  201 . In an embodiment, the second reverse air passage sequentially passes through the second counterflow inlet  203 , the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the second vent opening  201 , the first chamber  15 , and the second vent port  56 . The second reverse air passage passes from the second counterflow inlet  203  through the counterflow air inlet  301 , the counterflow air passage  30 , the counterflow air outlet  300 , the second vent opening  201 , the first chamber  15 , and the second vent port  55  in sequence to the second filter  121 . 
     The switching valve apparatus of this vacuum cleaner rotates relative to the outer casing  2  in the outer casing  2  through the counterflow air passage  30  or the valve core  3  so that the switching of the air passage can be achieved conveniently and efficiently. The mechanism of the switching valve apparatus is novel and ingenious and occupies a concentrated space so that the spatial layout can be facilitated. The first reverse air passage is an air passage between the first filter  120  and the fourth chamber  19 , and the second reverse air passage is an air passage between the second filter  121  and the fourth chamber  19 . The first reverse air passage is used for cleaning the first filter  120 , the second reverse air passage is used for cleaning the second filter  121 , and the first forward air passage and the second forward air passage are separately used for forward suction of the air. In the case where the counterflow air passage  30  or the valve core  3  is at the first angular position, the fan  11  performs suction through the two air passages (the first forward air passage and the second forward air passage). In the case where the counterflow air passage  30  or the valve core  3  is switched to the second angular position, the first filter  120  cleans the blockage in the first filter  120  through the first reverse air passage, and the fan  11  performs suction through the second forward air passage corresponding to the second filter  121 . In the case where the counterflow air passage  30  or the valve core  3  is switched to the third angular position, the second filter  121  cleans the blockage in the second filter  121  through the second reverse air passage, and the fan  11  performs suction through the first forward air passage corresponding to the first filter  120 . It can be seen that no matter whether the counterflow air passage  30  or the valve core  3  is switched to the second angular position or the third angular position, a forward air passage for forward suction and a reverse air passage for cleaning the filter exist at the same time so that a better cleaning effect on the filter can be ensured.