Multi-cyclone dust collecting device and vacuum cleaner including same

A vacuum cleaner comprising:

• a suction nozzle;
• a multi-cyclone dust collecting device connected to the suction nozzle;
• and
• a suction motor connected to the multi-cyclone dust collecting device and configured to generate a suction force,
• wherein the multi-cyclone dust collecting device comprises:
• a primary cyclone formed to firstly separate dirt from an introduced dirt-containing air;
• an intermediate wall that is disposed in a cylindrical shape inside the primary cyclone and includes a porous member;
• and
• a plurality of secondary cyclones disposed inside the intermediate wall and formed to separate fine dust from air discharged through the porous member of the intermediate wall from the primary cyclone, each of the plurality of secondary cyclones including a at least three inlets and one outlet,
• wherein the at least three inlets provided in each of the plurality of secondary cyclones protrude outward from a body of each of the plurality of secondary cyclones and include an inlet duct formed in a tangential direction with respect to an outer circumferential surface of each of the plurality of secondary cyclones,
• wherein an entrance of the inlet duct is located at a position lower than an upper end of the porous member of the intermediate wall,
• wherein the outlet of each of the plurality of secondary cyclone includes a discharge pipe and a lower end of the discharge pipe is positioned at a same level as or at a lower level than a lower end of the inlet duct provided at each of the at least three inlets,
• wherein each of the at least three inlets comprises:
• an opening formed in each of the plurality of secondary cyclones, and
• the inlet duct is formed to surround the opening,
• wherein the inlet duct comprises:
• an inflow guide wall disposed in a tangential direction with respect to the outer circumferential surface of the secondary cyclone;
• a top wall connecting an upper end of the inflow guide wall and an upper end of the secondary cyclone;
• and
• a bottom wall disposed in parallel with the top wall and connecting a lower end of the inflow guide wall and the outer circumferential surface of the secondary cyclone, and
• wherein each of the at least three inlets further includes an adjusting portion extending from the outer circumferential surface of the secondary cyclone corresponding to a start end of the inlet duct toward the opening.