Abstract: An air cleaner may include a filter element and a housing defining an inner space. The inner space may be divided by the filter element into a dust-side air chamber on an upstream side and a clean-side air chamber on a downstream side. Air introduced into the housing may be dischargable via an outlet pipe, to which an air flow sensor is attachable, connected to the clean-side air chamber. The outlet pipe may extend in a direction different from a normal to the filter element. A plurality of ribs may be disposed on an inner surface of a clean-side portion of the housing that defines the clean-side air chamber. The plurality of ribs may extend from a corner portion of the housing toward the filter element and the outlet pipe. A distance between adjacent ribs of the plurality of ribs may decrease in a direction toward the outlet pipe.

Abstract: An air cleaner capable of, even when a flow rate of air flow flowing in the air cleaner is high, performing flow rate measurement with high measurement accuracy via an air flow sensor attached to an outlet pipe is provided. The above problem can be solved by an air cleaner 1 including a plurality of ribs 41, 42, 43 disposed at an inner surface of a housing 2 defining a clean-side air chamber 23, the plurality of ribs 41, 42, 43 extending from a corner portion 24 of the housing, the corner portion 24 being distant from a filter element 4 and an outlet pipe 21, toward the filter element 4 and the outlet pipe 21 and terminating short of a surface 25 of the housing with the outlet pipe 21 provided, the plurality of ribs 41, 42, 43 being configured such that a distance d between adjacent ribs narrows toward the outlet pipe 21.