Abstract: An air cleaner degradation degree estimation device, includes: a processor configured to: acquire location information indicating a location of a vehicle; acquire information relating to an air pollution index in an area corresponding to the location information; calculate an air cleaner degradation degree based on a travel distance of the vehicle; and correct the air cleaner degradation degree based on the air pollution index.

Abstract: An air cleaner has a body, an intake part to take air into the body, an exhaust pipe to exhaust the air from the body, a mounting section to mount an air flow meter to the exhaust pipe, a rib disposed on an inner surface of the body, and a straightening element disposed on an inner surface of the exhaust pipe. The rib extends toward the exhaust pipe and the straightening element extends in a same direction where the rib extends. The straightening element is located closer to the body than the mounting section.

Abstract: An intake device includes an air filter that filters intake air for an internal combustion engine, a filter casing housing the air filter, and an air physical quantity sensor. The filter casing includes an intake passage to allow the intake air to pass from upstream to downstream of the air filter. The filter casing has a passage wall portion that is electrically conductive and exposed to the intake passage on a downstream side of the air filter. The air physical quantity sensor has: a sensor element that detects a specific physical quantity related to the intake air on a downstream side of the air filter; and a grounding structure electrically connected to the passage wall portion for grounding the sensor element.

Abstract: There is provided an air cleaner including: an outlet pipe through which air is discharged; an airflow meter that is inserted toward an interior of the outlet pipe through a wall of the outlet pipe; and a flow-regulating member that is formed projecting from an inner surface of the outlet pipe at a side of the airflow meter, the flow-regulating member including an edge that is formed with a peaked shape with respect to the inner surface and that runs along a direction of flow of air, a rear end that is formed at a downstream end of the edge in the direction of flow, and that is shaped cut sharply toward the inner surface and a width-narrowing portion that decreases in width in a circumferential direction of the outlet pipe on progression downstream in the direction of flow.

Abstract: There is provided an air cleaner including: an outlet pipe through which air is discharged; an airflow meter that is inserted toward an interior of the outlet pipe through a wall of the outlet pipe; and a flow-regulating member that is formed projecting from an inner surface of the outlet pipe at a leading end side of the airflow meter, the flow-regulating member including an edge that is formed with a peaked shape with respect to the inner surface and that runs along a direction of flow of air, a rear end that is formed at a downstream end of the edge in the direction of flow, and that is shaped cut sharply toward the inner surface and a width-narrowing portion that decreases in width in a circumferential direction of the outlet pipe on progression downstream in the direction of flow.

Abstract: An air cleaner has a body, an intake part to take air into the body, an exhaust pipe to exhaust the air from the body, a mounting section to mount an air flow meter to the exhaust pipe, a rib disposed on an inner surface of the body, and a straightening element disposed on an inner surface of the exhaust pipe. The rib extends toward the exhaust pipe and the straightening element extends in a same direction where the rib extends. The straightening element is located closer to the body than the mounting section.

Abstract: An intake device includes an air filter that filters intake air for an internal combustion engine, a filter casing housing the air filter, and an air physical quantity sensor. The filter casing includes an intake passage to allow the intake air to pass from upstream to downstream of the air filter. The filter casing has a passage wall portion that is electrically conductive and exposed to the intake passage on a downstream side of the air filter. The air physical quantity sensor has: a sensor element that detects a specific physical quantity related to the intake air on a downstream side of the air filter; and a grounding structure electrically connected to the passage wall portion for grounding the sensor element.

Abstract: A duct structure including a fin having a downstream end surface extending between an inner surface of a duct and a downstream end of a top surface of the fin in a height direction of the fin. As a result, a vortex can be intentionally generated in a downstream of the downstream end surface of the fin. Since a pressure in the vortex is lower than a pressure in a surrounding portion of the vortex, the vortex can draw a fluid flow having flowed along the top surface of the fin to the vortex and can change the flow to a flow flowing along a portion of the inner surface of the duct located downstream of the fin. As a result, a flow separation from the inner surface of the duct can be suppressed.

Abstract: There is provided an air cleaner including: an outlet pipe through which air is discharged; an airflow meter that is inserted toward an interior of the outlet pipe through a wall of the outlet pipe; and a flow-regulating member that is formed projecting from an inner surface of the outlet pipe at a leading end side of the airflow meter, the flow-regulating member including an edge that is formed with a peaked shape with respect to the inner surface and that runs along a direction of flow of air, a rear end that is formed at a downstream end of the edge in the direction of flow, and that is shaped cut sharply toward the inner surface and a width-narrowing portion that decreases in width in a circumferential direction of the outlet pipe on progression downstream in the direction of flow.

Abstract: There is provided an air cleaner including: an outlet pipe through which air is discharged; an airflow meter that is inserted toward an interior of the outlet pipe through a wall of the outlet pipe; and a flow-regulating member that is formed projecting from an inner surface of the outlet pipe at a side of the airflow meter, the flow-regulating member including an edge that is formed with a peaked shape with respect to the inner surface and that runs along a direction of flow of air, a rear end that is formed at a downstream end of the edge in the direction of flow, and that is shaped cut sharply toward the inner surface and a width-narrowing portion that decreases in width in a circumferential direction of the outlet pipe on progression downstream in the direction of flow.

Abstract: A duct structure including a fin having a downstream end surface extending between an inner surface of a duct and a downstream end of a top surface of the fin in a height direction of the fin. As a result, a vortex can be intentionally generated in a downstream of the downstream end surface of the fin. Since a pressure in the vortex is lower than a pressure in a surrounding portion of the vortex, the vortex can draw a fluid flow having flowed along the top surface of the fin to the vortex and can change the flow to a flow flowing along a portion of the inner surface of the duct located downstream of the fin. As a result, a flow separation from the inner surface of the duct can be suppressed.