A vehicle underbody structure includes a catalyst disposed in a front portion of an exhaust pipe; a cover member for covering the catalyst from above; and a heat insulator disposed inside a tunnel portion behind the catalyst and configured to cover the exhaust pipe from above. The heat insulator is disposed away from the tunnel portion by a predetermined gap in an up-down direction. A front portion of the heat insulator and a rear portion of the cover member are disposed in such a way as to overlap each other. A front end of the heat insulator is disposed on the upper side with respect to a rear end of the cover member.

An attachment device includes a support table member and a coupling mechanism. The coupling mechanism includes a coupling bolt and an abutment member having a nut portion. In the abutment member, there is formed a locking protrusion protruding to the side where an auxiliary machine fixing portion is present. In the auxiliary machine fixing portion, there is formed an insertion hole for the coupling bolt and an anti-rotation hole in which the locking protrusion can be fitted.

An exhaust gas purification device includes an upstream cylinder, a downstream cylinder, and a purifying cylinder. The upstream cylinder, the purifying cylinder, and the downstream cylinder each have at an end thereof a flange portion having a flat connecting surface. Each flange portion of one of the upstream and downstream flange portions of the purifying cylinder, and the flange portions of the upstream cylinder and the downstream cylinder includes an engagement pin having an engagement recess portion. Each flange portion of the other includes a pin hole and an engagement groove. The engagement recess portion is fitted into and engaged with the engagement groove.

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 present disclosure is directed to a flexible pipe assembly that includes a pipe, a sleeve, a first connection assembly, and a second connection assembly. The pipe of the flexible pipe assembly includes a first end portion that is coupled to an external vertical exhaust pipe that allows exhaust to escape from a truck and a second end portion that is coupled to a pipe to an outlet of an exhaust aftertreatment system (EAS). The pipe also includes a third portion, which is a bellows, coupling the first end portion to the second end portion of the pipe of the flexible pipe assembly. The first and second connection assemblies couple the sleeve to the pipe of the flexible pipe assembly by passing through holes in the sleeve and the pipe of the flexible pipe assembly.

A support structure for an exhaust system part that configures an exhaust system of an internal combustion engine for a vehicle includes a bracket and a support member. The bracket includes a first plate and a second plate. The first plate has both end portions attached to the second plate, and the second plate has both end portions attached to the exhaust system part. A first space is defined between the first plate and the second plate, and a second space is defined between the second plate and the exhaust system part. Each of the first space and the second space has a first open end disposed on the vehicle front side, and has a second open end disposed on the vehicle rear side. The first plate, the first space, the second plate, and the second space are disposed between the support member and the exhaust system part.

Systems are provided for a fastening system. In one example, the fastening system comprises a fastening element coupled to each of a subframe and an aftertreatment device. The fastening element is configured to alter a path of travel of the aftertreatment device in response to a deformation of the subframe.

An exhaust system member is provided on a vehicle-width-direction outer side relative to a vehicle body structure such as a side sill, while avoiding widening of the vehicle, enhancing shock absorption performance during a collision, and maintaining rigidity of the vehicle body. Embodiments include an engine disposed forward of a vehicle cabin, an engine exhaust system, and a hinge pillar extending vertically. The exhaust system includes a first exhaust system member beside the hinge pillar in the vehicle front-rear direction from the vehicle-width-direction outer side of the hinge pillar and extending forward of the hinge pillar, a second exhaust system member rearward of the hinge pillar, and a connection part connecting these exhaust system members. The connection part has a smaller length in the vehicle width direction than at least one of the first and second exhaust system members, and overlaps with the hinge pillar in the vehicle front-rear direction.

Methods and systems are provided for a coupling device. In one example, the coupling device may be formed of a composite material and positioned between an exhaust system and a vehicle chassis. The composite material may include aluminum particles dispersed in an elastomer matrix to reduce an overall thermal absorptivity of the composite material.

An elastic support for an exhaust system includes a support body, which is made of an elastic material. The support body includes a first fitting opening into which a first bracket is fitted and a second fitting opening into which a second bracket is fitted. An axis of the first fitting opening is orthogonal to an axis of the second fitting opening.