Methods and systems are provided for controlling imbalance with an exhaust tuning valve. In one example, a method may include adjusting a first exhaust tuning valve in response to combustion torque imbalance in a first and second group of cylinders. Additionally or alternatively, the position of the second exhaust tuning valve may be adjusted in response to an imbalance generated by the same group of cylinders.

A valve assembly for an exhaust system of a vehicle. The valve assembly includes a housing, a valve shaft and a valve plate. The housing defines an inlet, an outlet, and a longitudinally exhaust gas passageway in fluid communication with the inlet and the outlet. The valve shaft is rotatable. The valve plate is coupled to the valve shaft and is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is less restricted. The first housing includes spaced apart ears integral with and laterally extending from the first housing. The ears opposing each other. The shaft includes an axis of rotation being positioned at the ears and outside of the exhaust gas passageway.

An exhaust muffler includes a first muffler section having a tubular member made up of an inner pipe to which an exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and a second muffler section to each other, and the second muffler section having an outer shell, a first partition wall, a second partition wall, and a third partition wall. Exhaust gases delivered from the exhaust pipe are discharged from the first muffler section and the second muffler section out of the exhaust muffler. The second muffler section has a cross-sectional area larger than a cross-sectional area of the tubular member. The exhaust muffler includes a first expansion chamber, a second expansion chamber, and a third expansion chamber. The second muffler section includes a fluid communication pipe extending through the first partition wall and the second partition wall for leading exhaust gases from the first expansion chamber into the second expansion chamber, and an exhaust passage pipe held in fluid communication with the third expansion chamber and extending through the second partition and the third partition wall. The second partition wall has a fluid communication hole defined therein that provides fluid communication between the second expansion chamber and the third expansion chamber. There is thus provided an engine exhaust device capable of increasing a silencing capability by increasing the length of a route through which the exhaust gases flow while maintaining the length of the exhaust device.

A valve assembly for a vehicle exhaust system includes at least one pipe enclosing an exhaust gas flow path, the pipe defining a central axis, and at least one flexible flap positioned within the exhaust gas flowpath. The at least one flexible flap has one fixed edge held fixed to the pipe and extends to a distal edge that is free to bend in response to an increase in exhaust gas flow pressure to provide a variable restriction to flow through the pipe that varies in response to a pressure difference upstream and downstream of the at least one flexible flap.

An exhaust system for an internal combustion engine and having at least an exhaust duct, which originates from the internal combustion engine and has an end part, which ends with an outlet opening, through which exhaust gases are released into the atmosphere. The end part of the exhaust duct has at least one movable wall, which can be moved to different positions to vary the width of the outlet opening. There are provided a motor-driven actuator device, which is configured to move the movable wall and can be electronically controlled, and a control unit, which is configured to vary, by controlling the actuator device, the position of the movable wall depending on a rotation speed of the internal combustion engine and on an engine load of the internal combustion engine.

A transport refrigeration unit (TRU) is provided and includes a power generation unit, a catalytic element, an exhaust pipe, first and second tubular elements fluidly interposed between the power generation unit and the catalytic element and between the catalytic element and the exhaust pipe, respectively, at least one of first and second throttle valves and a control system. The at least one of first and second throttle valves are operably disposed to control fluid flows in the first and second tubular elements, respectively. The control system is configured to control the power generation unit and the at least one of the first and second throttle valves to effect the sound produced by the TRU.

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 road grade estimate. The road grade estimate may be based on a vehicle's present position on a road or a position that is a distance away from the vehicle's present position.

A valve assembly for an exhaust system of a vehicle comprises a housing defining an inlet, an outlet, and a longitudinally extending exhaust gas passageway in fluid communication with the inlet and the outlet. The valve assembly further comprises a valve flap disposed in the housing and rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is less restricted. A mass damper is disposed within the exhaust gas passageway and attached to the valve flap. The mass damper includes end portions and an intermediate portion disposed between the end portions with the intermediate portion having a thickness that is greater than a thickness of the end portions. The mass damper is positioned proximate an inner surface of the housing and positioned between the valve flap and the housing when the valve flap is at the second position.

A system for regulating performance characteristics of a vehicle includes an engine configured to output an exhaust gas. The system further comprises an emissions system in fluid communication with the engine, the emissions system configured to clean the exhaust gas. The system further comprises a valve system in fluid communication with the emissions system, the valve system configured to regulate a flow of the exhaust gas. The valve system comprises a vane movable between a forward open position, a closed position, and a rear open position. The valve system further comprises a biasing member configured to bias the vane in the forward open position. The valve system further comprises a bypass channel configured to provide a bypass flow path for the exhaust gas to control a backpressure on the vane.

Methods and systems are provided for diagnosing an active exhaust valve in an exhaust system based on thermal data. In one example, a method may include indicating degradation of a first active exhaust valve positioned in a first exhaust pipe of a first engine bank based on a difference between a first temperature of exhaust downstream of the first active exhaust valve and a second temperature of exhaust downstream of a second active exhaust valve positioned in a second exhaust pipe of a second engine bank. Degradation of the valve may be confirmed based on thermal image data acquired at outlets of the first and second exhaust pipes.