A turbocharger (10) that uses exhaust gas flow to drive a turbine wheel (12) having a barrel or piston-type wastegate valve assembly (26, 126) with a wastegate valve (28, 128) that controls exhaust gas flow bypassing the turbine wheel (12) to control turbine work. A cylinder (30, 130), which may have a through hole (32, 132), is moveable in a tubular chamber (22) and functionally operates with a wastegate port (24) in the turbine housing (20) for controlling exhaust gas flow. An actuator (36, 136) operably controls movement of the cylinder (30, 130).

A turbocharger includes a turbine housing and a wastegate assembly. The turbine housing has a wastegate duct defining a wastegate channel and a valve seat disposed about the wastegate channel. The wastegate assembly has a valve body engageable with the valve seat and a shaft fixed to the valve body at a connection interface for selectively engaging the valve body with the valve seat at a first plane. The connection interface has a centroid and a second plane tangential to the centroid. A second axis is normal to the second plane and is angularly tilted relative to a first axis normal to the first plane at which the valve body and the valve seat are engaged.

In an exhaust gas flow control system for an internal combustion engine, with a first exhaust gas duct and a second exhaust gas duct, through both of which exhaust gas from the internal combustion engine can flow to a turbine of an exhaust gas turbocharger with an exhaust gas recirculation line branching off the first exhaust gas duct, a shut-off element is provided which is adjustable between a closed position in which exhaust gas is prevented from flowing into the exhaust gas recirculation line and directing it via a communication passage into the second exhaust gas duct, and at least a first open position in which exhaust gas is directed out of the first exhaust gas duct into the exhaust gas recirculation line while blocking the communication passage between the first and second exhaust gas ducts and a second open position wherein both the first and the second exhaust gas ducts as well as the communication passage between the two ducts is open but the recirculation line is closed.

In a spark-ignition internal combustion engine having multiple cylinders, successive segment time periods assigned to the individual cylinders during working strokes thereof, and subsequently irregular running values are determined from the segment time periods. In a predefined speed range of the engine, the irregular running values of the cylinders are compared with a predefined threshold, and suspected auto-ignition for a first cylinder is detected if the irregular running value of a second cylinder located before the first cylinder in terms of timing of the ignition sequence undershoots the threshold. Fuel to the first cylinder suspected of auto-ignition is interrupted for a predefined number of cycles, and the fuel interruption influence on the irregular running values of the second cylinder during the cycles is detected. The suspected auto-ignition of the first cylinder is either confirmed or rejected based on the irregular running values occurring at the second cylinder.

The present invention relates to a relief valve (1) for a turbocharger, in which the crank arm (3) is made of a first material and the shaft (4) is made of a second material different from the first material used for manufacturing the crank arm (3), each of the materials containing a composition that provides the necessary properties according to the application of each component of the relief valve (1). The present invention also relates to a process for manufacturing the relief valve (1), which allows the crank arm (3) and the shaft (4) to be manufactured separately, using different materials for the manufacture of each component.

A turbocharger assembly may include a turbine wheel. A turbine housing may surround at least part of the turbine wheel. A wastegate port may be defined by the turbine housing and may provide a bypass around the turbine wheel. A valve plate may be movable between a first position closing the wastegate port and a number of additional positions opening the wastegate port. The valve plate may have a face that faces the wastegate port. A shaft may be connected to the valve plate and may rotate about an axis at a pivot point. The pivot point may be located on an opposite side of a line from the valve plate, wherein the line may extend from the face and in a plane within which the face exists when the wastegate port is closed by the valve plate.

An electric waste gate valve control device controls a waste gate valve provided in a waste gate passage that bypasses a portion between an upstream and a downstream of a turbine driven by exhaust of an engine and opening/closing the waste gate passage by an electric actuator. The electric waste gate valve control device includes, a position sensor that detects a position of the waste gate valve; an actuator controller that controls the electric actuator such that an opening degree of the waste gate valve becomes a target opening degree; and a fully closed position learning unit that performs fully closed position learning to acquire the position of the waste gate valve at a time when the electric actuator is driven to bring the waste gate valve into a fully closed state.

Methods and systems are provided for operating a branched exhaust assembly in a vehicle engine in order to increase catalyst efficiency and reduce engine emissions. In one example, a method may include, during a cold-start condition, flowing exhaust first through a three-way catalyst then through an underbody converter and then through a turbine, each exhaust component housed on different branches on the branched exhaust assembly. After catalyst activation, exhaust may flow first through the turbine, then through the underbody converter and then through the three-way catalyst, and during high engine load, exhaust may simultaneously flow through two branches of the branched exhaust assembly, partially bypassing the turbine.

Methods and systems are provided for pressure control in a boosted engine system. A variable geometry turbine (VGT) geometry, and/or wastegate (WG), and/or an exhaust gas recirculation (EGR) valve opening is adjusted based a difference between the exhaust pressure and an intake pressure, and optionally other signals (e.g., engine speed, exhaust pressure) in order to reduce the difference between exhaust and intake manifold pressures, thereby reducing pumping work losses.

Valve element for an exhaust-gas turbocharger, having a spindle which has a longitudinal extent, a lever which extends from the spindle laterally in relation to the longitudinal extent of said spindle and which has a through opening, a valve flap plate, a substantially disc-shaped fastening element, and a shank which extends through the through opening and which connects the valve flap plate to the fastening element, wherein the valve flap plate and the fastening element are connected to one another by way of a shank extending through the through opening of the lever, and wherein a spring element is provided for generating a preload between shank and lever.