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.

A combined mass airflow sensor and hydrocarbon trap is provided for absorbing evaporative hydrocarbon emissions from an air intake duct of an internal combustion engine. The combined mass airflow sensor and hydrocarbon trap comprises a duct that supports a hydrocarbon absorbing sheet in an unfolded configuration within a housing. The duct communicates an airstream from an air filter to the air intake duct during operation of the internal combustion engine. An opening in the housing receives a mass airflow sensor into the duct, such that the mass airflow sensor is disposed within the airstream. Guide vanes extending across the duct reduce air turbulence within the airstream passing by the mass airflow sensor. Ports disposed along the duct allow the evaporative hydrocarbon emissions to be drawn into the interior and arrested by the hydrocarbon absorbing sheet when the internal combustion engine is not operating.

A flowmeter is inserted into a main passage through which a target fluid flows. The flowmeter includes a housing, a sub passage, an inlet portion, an outlet portion, a flow rate detector, and a protrusion. The housing includes a side surface and a tip end surface. A part of the target fluid flows into the sub passage from the main passage. The target fluid flows into the sub passage through the inlet portion and flows out of the sub passage through the outlet portion. The flow rate detector is configured to detect a flow rate of the target fluid flowing through the sub passage. The tip end surface includes a first end area and a second end area. The protrusion protrudes from the tip end surface and is located in both the first end area and the second end area.

A straddle-type vehicle comprises a supercharging device which compresses intake-air to be sent to a combustion chamber of an engine; a catalyst provided in an exhaust passage through which an exhaust gas emitted from the engine flows; and a control section which controls the engine, wherein the control section performs an increase suppressing control for suppressing an increase in an exhaust gas temperature, in a case where the control section estimates that the exhaust gas temperature has exceeded an increase suppressing temperature set to be equal to or lower than a catalyst permissible temperature.

A filter assembly includes a conditioning device that conditions a flow of air upstream of a mass air flow sensor. The filter assembly includes a support frame. The filter assembly further includes a filter media coupled to the support frame, the filter media having a dirty side configured to receive a stream of air and a clean side configured to output a stream of air that has been filtered through the filter media. The filter assembly includes a conditioning device coupled to the support frame, the conditioning device positioned in a downstream direction from the clean side of the filter media with respect to the stream of air, the conditioning device offset from the clean side of the filter media by a separation distance.

A rectification structural body includes an inlet port into which air from an air cleaner flows, an outlet port from which air flows out toward an airflow sensor, and a chamber provided between the inlet port and the outlet port. The inlet port and the outlet port are provided in such directions and at such positions that an air flow is bent in the chamber. The chamber includes two cases of a first case and a second case, the chamber being divided into the two cases.

An air cleaner for a vehicle includes a case having an air inlet pipe and an air outlet pipe. A cover is removably attached to the case for covering an open top portion of the case. With the cover attached to the case an interior of the air cleaner defines a flow passage directed through the air cleaner from the air inlet pipe to the air outlet pipe. A filter element is received in the interior and is arranged over the flow passage. The flow passage immediately downstream of the filter element includes an elbow-shaped section for redirecting airflow from the filter element toward the air outlet pipe. The elbow-shaped section is provided with at least one first guide rib shaped correspondingly to the elbow-shaped section. The flow passage upstream of the air outlet pipe defines a branching section formed as an acoustic resonator for reducing air intake noise.

A combined mass airflow sensor and hydrocarbon trap is provided for absorbing evaporative hydrocarbon emissions from an air intake duct of an internal combustion engine. The combined mass airflow sensor and hydrocarbon trap comprises a duct that supports a hydrocarbon absorbing sheet in an unfolded configuration within a housing. The duct communicates an airstream from an air filter to the air intake duct during operation of the internal combustion engine. An opening in the housing receives a mass airflow sensor into the duct, such that the mass airflow sensor is disposed within the airstream. Guide vanes extending across the duct reduce air turbulence within the airstream passing by the mass airflow sensor. Ports disposed along the duct allow the evaporative hydrocarbon emissions to be drawn into the interior and arrested by the hydrocarbon absorbing sheet when the internal combustion engine is not operating.

A vehicle provided with an engine, at least one air intake through which the engine takes in the external air needed to operate, and an air filter, which is arranged in the area of the air intake; the air filter comprises: at least one wave-shaped filtering material panel; an outer reinforcement mesh, an inner reinforcement mesh; and a heating device which is electrically connected to a group of electrified wires of the outer reinforcement mesh and is designed to cause an electric current to flow through said electrified wires, so as to generate heat, due to the Joule effect, on the inside of said outer reinforcement mesh.

A flowmeter is inserted into a main passage through which a target fluid flows. The flowmeter includes a housing, a sub passage, an inlet portion, an outlet portion, a flow rate detector, and a protrusion. The housing includes a side surface and a tip end surface. A part of the target fluid flows into the sub passage from the main passage. The target fluid flows into the sub passage through the inlet portion and flows out of the sub passage through the outlet portion. The flow rate detector is configured to detect a flow rate of the target fluid flowing through the sub passage. The tip end surface includes a first end area and a second end area. The protrusion protrudes from the tip end surface and is located in both the first end area and the second end area.