Methods and systems are provided for an engine including a humidity sensor. Degradation of the humidity sensor may be determined based on a change in intake air relative humidity as compared to a change in intake air temperature or pressure, under selected conditions. An amount of exhaust gas recirculated to an engine intake is adjusted differently based on whether the humidity sensor is degraded or functional.

Methods and systems are provided for an engine including a humidity sensor. Degradation of the humidity sensor may be determined based on a change in intake air relative humidity as compared to a change in intake air temperature or pressure, under selected conditions. An amount of exhaust gas recirculated to an engine intake is adjusted differently based on whether the humidity sensor is degraded or functional.

Embodiments of the present disclosure present a valve assembly that includes a valve body having a gas passage bore, a valving bore extending along a longitudinal axis and intersecting the gas passage bore, a first bearing surface concentric with the longitudinal axis and a radially spaced apart second bearing surface concentric with the longitudinal axis, wherein an interface of the gas passage bore and the valving bore defines a flow port radially intermediate the first bearing surface and the second bearing surface. The valve assembly further includes a shaft valve extending along the longitudinal axis and rotatably mounted in the valving bore.

Embodiments of the present disclosure present a valve assembly that includes a valve body having a gas passage bore, a valving bore extending along a longitudinal axis and intersecting the gas passage bore, a first bearing surface concentric with the longitudinal axis and a radially spaced apart second bearing surface concentric with the longitudinal axis, wherein an interface of the gas passage bore and the valving bore defines a flow port radially intermediate the first bearing surface and the second bearing surface. The valve assembly further includes a shaft valve extending along the longitudinal axis and rotatably mounted in the valving bore.

The present invention relates to an oil tank ventilation device for a hydraulic brake unit of a tramcar, comprising a vent plug, a sealing ring, a gas guide hole and a gas guide pipe; the gas guide hole is a through-hole structure arranged at an upper end inside an integrated valve block; the communications of electrical element protection case, integrated valve block and the oil tank are realized by the gas guide pipe stretched into an air chamber of the oil tank and by the vent plug configured in the electrical element protection case. When the surface of the oil tank is covered with ice or snow, the rain or snow can be effectively prevent from falling on the vent plug body and the driving safety of the train is ensured.

Embodiments of the present disclosure present a valve assembly that includes a valve body having a gas passage bore, a valving bore extending along a longitudinal axis and intersecting the gas passage bore, a first bearing surface concentric with the longitudinal axis and a radially spaced apart second bearing surface concentric with the longitudinal axis, wherein an interface of the gas passage bore and the valving bore defines a flow port radially intermediate the first bearing surface and the second bearing surface. The valve assembly further includes a shaft valve extending along the longitudinal axis and rotatably mounted in the valving bore.

Embodiments of the present disclosure present a valve assembly that includes a valve body having a gas passage bore, a valving bore extending along a longitudinal axis and intersecting the gas passage bore, a first bearing surface concentric with the longitudinal axis and a radially spaced apart second bearing surface concentric with the longitudinal axis, wherein an interface of the gas passage bore and the valving bore defines a flow port radially intermediate the first bearing surface and the second bearing surface. The valve assembly further includes a shaft valve extending along the longitudinal axis and rotatably mounted in the valving bore.

An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.

An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.

The invention has an object to control an EGR amount accurately in transient time. An ECU switches EGR control to the one-valve EGR control and the both-valve EGR control based on a request EGR amount. When the EGR control is switched to the one-valve EGR control from the both-valve EGR control, an EGR valve of one bank is closed first. Next, during a time period until an opening degree restriction time period elapses after the EGR valve is closed, an opening degree of an EGR valve of the other bank is restricted to be smaller than a one-valve target opening degree. Subsequently, when the opening degree restriction time period elapses, restriction of the opening degree of the EGR valve is cancelled, and the opening degree of the EGR valve is changes to the one-valve target opening degree.