The invention relates to α/β-sialon-based materials. The invention particularly relates to α/β-sialon-based materials that have an improved sintering activity and impart high edge strength to the sintered molded articles made of said materials.

An exhaust purification apparatus for an internal combustion engine has an exhaust purification catalytic agent disposed in an exhaust passage. The exhaust purification apparatus for the internal combustion engine has an exhaust throttle valve, an actuator, and a controller. The exhaust throttle valve is arranged upstream of the exhaust purification catalytic agent in the exhaust passage and changes a passage sectional area of the exhaust passage. The actuator operates the exhaust throttle valve to be open and closed. The controller controls the exhaust throttle valve to be open and closed through the actuator. The controller decreases an opening degree of the exhaust throttle valve to narrow the passage sectional area of the exhaust passage upon a heating request for heating the exhaust purification catalytic agent.

An exhaust system for an engine has a volume element such as a muffler or a silencer. First and second exhaust pipes are connected as dual exhaust pipes upstream of or downstream of the volume element. The first exhaust pipe has a first length (L1). A valve is positioned in the second exhaust pipe at a distance (D) from the volume element. The distance D is a fraction of L1 such that the second pipe is a resonator for the first pipe with the valve in a closed position. A method of controlling exhaust noise includes positioning a valve in the first exhaust pipe at a distance (D) from a volume element with D being a specified fraction of a length of the second exhaust pipe, and closing the valve such that the first pipe provides a resonator for the second pipe to counteract standing wave in the second pipe.

Provided is a muffler valve 1 that opens and closes an exhaust passage according to a pressure of an exhaust gas of an engine. A valve body 3 is swingably supported by a support shaft 4 with respect to a valve seat 2 having an opening 22, the valve body 3 is urged in a closing direction by a coil spring 5 externally inserted on the support shaft 4, a valve seat hook portion 23 is provided so as to embrace both ends of the support shaft 4 in a circumferential direction and is fixed to the support shaft 4, and a valve body winding portion 34 is provided so as to embrace the coil spring 5 in the circumferential direction from a direction opposite to the valve seat hook portion 23 and embrace the coil spring 5 over an entire length of the coil spring 5 in the circumferential direction. It is possible to prevent or suppress axial misalignment of the coil spring coaxially externally inserted on the support shaft for opening and closing the valve body as much as possible, and appropriately control the opening and closing of the valve body with high stability.

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.

In a distribution flow path that allows engine coolant to circulate between an exhaust heat recovery unit and an engine, an upstream flow path on the upstream side of the engine and a downstream flow path on the downstream side of the engine are communicated with each other by means of a bypass flow path to thereby form a short flow path with a shorter flow path length than in a case where the engine coolant that has exited the exhaust heat recovery unit passes through the engine. A valve that can adjust the amount of the engine coolant flowing to the bypass flow path and a short flow path pump are disposed.

Methods and systems to control a temperature of a selective catalytic reduction catalyst are disclosed. In one example, a diverter valve that includes two butterfly valves that are coupled together via a shaft is adjusted to control a temperature at an inlet of the selective catalytic reduction catalyst so that the selective catalytic reduction catalyst may operate efficiently.

There is provided an exhaust-gas aftertreatment arrangement for an internal combustion engine comprising a first catalytic converter, a second catalytic converter arranged in parallel with the first catalytic converter, the first and second catalytic converters being arranged to receive exhaust gas from an engine, a connection pipe fluidly connecting an outlet of the second catalytic converter with an inlet of the first catalytic converter, thereby allowing a flow of exhaust gas through the connection pipe, and an outlet valve arranged in the outlet of the second catalytic converter and downstream of the location of the connection pipe, wherein the outlet valve is configured to control a flow of exhaust gas through the second catalytic converter. There is also provided a method for controlling an exhaust-gas aftertreatment arrangement.

An aftertreatment system connected downstream an internal combustion engine arrangement for receiving exhaust gases conveyed from the internal combustion engine arrangement during operation thereof, wherein the aftertreatment system comprises first and second catalytic devices in series, wherein a gap is there between.

Systems and methods for reducing heat loss to a turbocharger during cold engine starting are described. In one example, a turbocharger bypass pipe and a turbocharger turbine pipe are oriented at forty five degrees relative to a longitudinal axis of a catalyst so that a turbocharger turbine may be completely bypassed, thereby increasing the amount of energy that may be transferred to the catalyst.