Methods and systems are provided for adjusting a position of an exhaust valve that regulates engine exhaust noise. In one example, the position of the exhaust valve is adjusted according to a distance between a first vehicle and a second vehicle. The exhaust valve may be adjusted to reduce an exhaust noise level when the distance between the first vehicle and the second vehicle is less than a threshold distance.

A road vehicle comprising: a passenger compartment; an internal combustion engine; an exhaust system, which releases into the atmosphere the gases generated by the combustion, is connected to the internal combustion engine, and ends with at least one silencer having at least one outlet pipe; and an exhaust noise transmission device, which is provided with a transmission conduit, which originates close to the outlet pipe of the silencer, ends in the area of a wall of the passenger compartment, and is provided, on the inside, with at least one insulating element, which is arranged inside the transmission conduit so as to tightly seal the transmission conduit.

A method is provided for controlling nitrogen oxide emissions in the exhaust gas of an internal combustion engine by means of successive actuation of catalytic converters in the exhaust tract and of the internal combustion engine, wherein the catalytic converters or the internal combustion engine are actuated in succession if the actuation of a first device is not sufficient for reducing the nitrogen oxide emissions. An arrangement for carrying out the method is also provided.

A work vehicle includes: a first exhaust pipe to which engine exhaust is sent; and a second exhaust pipe that has an inlet having an outer diameter larger than an outlet of the first exhaust pipe, the outlet of the first exhaust pipe and the inlet of the second exhaust pipe being disposed in proximity such that the outlet of the first exhaust pipe is positioned inside the inlet of the second exhaust pipe; a partition that divides a cross section of the outlet of the first exhaust pipe into a plurality of divided regions when viewed from the flow direction and partitions the adjacent divided regions at intervals.

A hedge trimmer has at least one cutting blade and an internal combustion engine operatively connected to the at least one cutting blade so as to drive the at least one cutting blade reciprocatingly. The internal combustion engine has an exhaust gas muffler with an outlet for discharging exhaust gases from the exhaust gas muffler. A multi-part exhaust gas pipe is connected seal-tightly to the outlet of the exhaust gas muffler and connects the outlet of the exhaust gas muffler to an outlet opening where the exhaust gases exit from the hedge trimmer. The multi-part exhaust gas pipe has a plurality of pipe sections, including at least a first pipe section and a second pipe section, wherein the second pipe section is embodied separate from the first pipe section. At least one of the plurality of pipe sections is made of plastic material.

A method for automatically changing the engine exhaust sound in conjunction with the traveling mode implemented by the exhaust system applied to the vehicle may vary the valve opening of an electronic variable valve provided in a first tail pipe of first and second tail pipes of muffler discharging the exhaust gas coming from an engine by a mode recognition logic connected to an engine ECU to the atmosphere, and control the variation of the valve opening with the engine torque and the engine RPM based on a change in an accelerator pedal stroke in any one of a SMART DRIVE MODE-ECO state, a SMART DRIVE MODE-COMFORT state, and a SMART DRIVE MODE-SPORT state, implementing a quiet engine exhaust sound and a sporty engine exhaust sound depending on various vehicle traveling states provided by the SMART DRIVE MODE and increasing vehicle/engine outputs.

A two-stage venturi cooler comprises a first tubular conduit having a longitudinal axis, the first elongate tubular conduit having an exhaust gas inlet at one end, a mixed gas outlet at an opposing end, and a cooling gas inlet, wherein structures inside the first stage define a venturi that forms a column of mixed gas, wherein the column of mixed gas comprises a ring of exhaust gas surrounding a core of cooling gas; and a second tubular conduit that is coaxial with the first tubular conduit, wherein the second tubular conduit has a mixed gas inlet at one end and a mixed gas outlet at an opposing end, and wherein the mixed gas inlet is to receive the column of mixed gas and to surround the column of mixed gas with an entrained column of ambient air.

The exhaust pipe comprises an inlet pipe, an outlet pipe and a bend portion arranged between the inlet pipe and the outlet pipe. The bend portion comprises an inlet bend and an outlet bend, wherein a central bend portion defines an intermediate section of inlet bend and outlet bend and wherein the inlet bend and the outlet bend each cover 50 percent of the total bend angle covered by the bend portion. The central bend portion comprises a diameter, which is smaller than a diameter of the inlet bend and of the outlet bend in a bending plane. In addition a bend radius R of the bend portion varies along the bend portion such that a bend radius of the inlet bend is larger than a bend radius of the outlet bend.

An exhaust handling system comprising: an exhaust pipe having an exhaust outlet, said exhaust outlet having a nozzle arranged to vent exhaust gas; at least one acceleration jet arranged to project an air flow at a velocity head greater than that of the vented exhaust gas; wherein the at least one acceleration jet and exhaust outlet are positioned to project the air flow so as to impinge on a path of said vented exhaust gas, and consequently transfer velocity head to the vented exhaust gas.

Provided is an exhaust apparatus for a vehicle, being capable of performing a normal detection of a nitrogen oxide (NOx) concentration in exhaust gas without involving increase in the size and the cost. The exhaust apparatus includes an exhaust pipe having an upstream end connected to an aftertreatment device and a downstream end enclosing an exhaust port at a position higher than the upstream end, a NOx sensor to be retained in the exhaust pipe, and a water barrier wall provided inside the exhaust pipe. The water barrier wall has a shape to form a shield between the NOx sensor and the exhaust port while leaving a gas inlet that allows the exhaust gas to flow to the NOx sensor from the aftertreatment device through the gas inlet.