An exhaust apparatus includes a chamber disposed below an engine, an inlet pipe guiding exhaust gas from an exhaust pipe to the chamber, a tail pipe discharging the exhaust gas from the chamber to an outside, a first partition wall partitioning an inside of the chamber to a pair of left and right spaces, and a second partition wall partitioning one of the left and right spaces to a pair of front and rear spaces. Another of the left and right spaces is a first expansion chamber into which the inlet pipe enters. A rear space of the front and rear spaces is a second expansion chamber disposed downstream of the first expansion chamber. A front space of the front and rear spaces is a third expansion chamber disposed downstream of the second expansion chamber, and the tail pipe enters into the front space.

An exhaust structure for a saddle riding vehicle includes: an exhaust pipe connected to an internal combustion engine; and a catalyst disposed in the exhaust pipe; the exhaust pipe including a catalyst case unit housing the catalyst and upstream side exhaust pipes disposed on an upstream side of the catalyst case unit; the catalyst case unit having a larger diameter than the upstream side exhaust pipes; the upstream side exhaust pipes being connected to the catalyst case unit in a connecting portion located on an upstream side of the catalyst in a flow of exhaust; in the connecting portion, axes of the upstream side exhaust pipes and an axis of the catalyst case unit being in substantially right-angled positional relation to each other.

The present invention provides an exhaust gas purification catalyst including a base material and a catalyst layer 20 that is arranged on the base material. The catalyst layer 20 includes a catalyst metal and a carrying material carrying the catalyst metal. The catalyst layer 20 satisfies below: (1) in a pore distribution curve measured by a mercury porosimeter, a peak for the largest pore volume exists within a range of a pore diameter equal to or more than 1 μm and not more than 10 μm; and (2) on an electron microscopy observation image (with a 1000-fold magnification) of a surface of the catalyst layer 20, when areas of a plurality of voids comprised in the electron microscopy observation image are respectively calculated, a standard deviation for the areas of the plurality of voids is not more than 30 μm.sup.2.

The present disclosure relates to an all-terrain vehicle and an exhaust assembly for an all-terrain vehicle. The all-terrain vehicle includes: a frame, a V-type twin-cylinder engine and an exhaust assembly. The V-type twin-cylinder engine has a first exhaust port and a second exhaust port, and a cylinder corresponding to the first exhaust port is located in front of a cylinder corresponding to the second exhaust port. The V-type twin-cylinder engine is mounted on the frame. The exhaust pipe group has a first end coupled to the first exhaust port, a second end coupled to the second exhaust port, and a third end coupled to a pipe of the muffler. The exhaust pipe group is divided into at least two exhaust pipes, and adjacent exhaust pipes are flexibly coupled.

A straddled vehicle having an engine unit supported by a vehicle body frame. The engine unit includes an engine body, a turbocharger, and an exhaust device. The exhaust device includes an exhaust pipe and a muffler that are connected to each other to form a portion of an exhaust passage, to allow the exhaust gas passed through the turbocharger to pass therethrough, and a first catalyst and a second catalyst that are arranged in this order along a direction in which the exhaust gas flows through the exhaust pipe. The exhaust pipe has an upstream end thereof connected to the turbocharger, a downstream end thereof connected to the muffler, and a corner section that is bent in at least a part thereof between a downstream end of the first catalyst and an upstream end of the second catalyst, the catalysts not being arranged in the corner section.

The invention presented is a crossover section for a vehicle exhaust system that includes a middle pipe and two outer pipes, each outer pipe in contact with and attached to the middle pipe. Diversion gates extend from the middle pipe into each of the outer pipes to divert a sample of exhaust gas into the middle pipe. A sensor, such as an oxygen sensor, is provided to measure one or more components of the combined exhaust. Also provided is an exhaust system that includes the inventive crossover section and a vehicle that includes one or more of the inventive exhaust systems.

Methods, systems, and vehicles that control the temperature of a device included in the vehicle are presented herein. The temperature of the device is controlled by ventilating the device with drivetrain air, such as transmission cooling air. In some embodiments, the device is at a greater temperature than the drivetrain air, which cools the device. In other embodiments, the device is at a lesser temperature than the drivetrain air, which heats the device. The drivetrain air is provided to the device through an exhaust duct coupled to the vehicle's transmission. The drivetrain exhaust air is preferably circulated by the transmission. The transmission may be a continuously variable transmission. The device may be an oxygen sensor that is coupled to an engine exhaust pipe. The oxygen sensor is thermally coupled to the engine exhaust and the engine exhaust pipe, which are at greater temperatures than the transmission exhaust air.

A saddle-riding type vehicle exhaust structure includes: an exhaust pipe that is connected to an exhaust port connecting to a combustion chamber of an engine and has a circular cross-sectional shape which is orthogonal to an exhaust flow direction; and a muffler that is connected to a downstream side in the exhaust flow direction of the exhaust pipe, wherein the exhaust pipe includes a muffler connection part that is connected to the muffler, an exhaust pipe upstream part that is connected to an upstream side in the exhaust flow direction of the muffler connection part, and an exhaust pipe downstream part that is connected to a downstream side in the exhaust flow direction of the muffler connection part, a cross-sectional area that is orthogonal to the exhaust flow direction of the muffler connection part is larger than each of a minimum value of a cross-sectional area that is orthogonal to an exhaust flow direction of the exhaust pipe upstream part and a minimum value of a cross-sectional area that is orthogonal to an exhaust flow direction of the exhaust pipe downstream part, and a vehicle width direction size of the cross-sectional shape of the muffler connection part and a vertical direction size of the cross-sectional shape of the muffler connection part are different from each other.

A catalytic converter for treatment of exhaust gases from a motorcycle engine includes a housing having an upstream end and a downstream end. A housing body extends between the upstream end and the downstream end. A catalyst mantle is positioned within the body of the housing such that a void is formed between the catalyst mantle and the housing body. A catalyst is positioned within the catalyst mantle. An insulator is positioned within the void between the housing body and the catalyst mantle.

An exhaust device that guides exhaust gas from an exhaust pipe in front of an engine to a muffler in a rear of the engine is provided. The exhaust device includes a primary catalyst case accommodating a primary catalyst configured to purify the exhaust gas at a downstream side from the exhaust pipe, a secondary catalyst case accommodating a secondary catalyst configured to purify the exhaust gas at a downstream side from the primary catalyst, and a chamber formed with a muffling chamber configured to reduce an exhaust noise at a downstream side from the secondary catalyst. The primary catalyst case is disposed in a front space of the engine. The secondary catalyst case is disposed on a front part of a lower space of the engine. The chamber is disposed so as to occupy at least a rear part of the lower space of the engine.