A coolant control valve unit for a vehicle engine is disclosed. The coolant control valve unit includes a rod at one side of which a valve opening and closing a coolant passage, a cap at which a rod groove into which one end of the rod is inserted is provided, a cap elastic member inserted inside the rod groove to elastically support one end of the rod outwardly, a cam with one surface of which a driving axle is connected and at the other surface of which at least one of pressing surface is provided in a rotational direction with respect to a rotational center portion, and a valve elastic member elastically supporting the valve to one side so that the cap contacts with the pressing surface.

A coolant control valve unit for a vehicle engine is disclosed. The coolant control valve unit includes a rod at one side of which a valve opening and closing a coolant passage, a cap at which a rod groove into which one end of the rod is inserted is provided, a cap elastic member inserted inside the rod groove to elastically support one end of the rod outwardly, a cam with one surface of which a driving axle is connected and at the other surface of which at least one of pressing surface is provided in a rotational direction with respect to a rotational center portion, and a valve elastic member elastically supporting the valve to one side so that the cap contacts with the pressing surface.

An exhaust gas control valve for regulating a flow of exhaust gas includes a housing having an interior wall defining a housing interior, a yoke disposed in the housing interior and having a length and an axis extending along the length, with the yoke being moveable between a first and second yoke position. The exhaust gas control valve further includes a valve member including a valve shaft and a valve body. The valve member is moveable between a first valve position and a second valve position. The exhaust gas control valve also includes a retainer coupled to the yoke, and a biasing member disposed in the housing interior and coupled to the yoke and the retainer to bias the yoke and the retainer in opposite directions, with the biasing member being configured to prevent free play of the yoke and the valve member with respect to said housing.

An exhaust gas control valve for regulating a flow of exhaust gas includes a housing having an interior wall defining a housing interior, a yoke disposed in the housing interior and having a length and an axis extending along the length, with the yoke being moveable between a first and second yoke position. The exhaust gas control valve further includes a valve member including a valve shaft and a valve body. The valve member is moveable between a first valve position and a second valve position. The exhaust gas control valve also includes a retainer coupled to the yoke, and a biasing member disposed in the housing interior and coupled to the yoke and the retainer to bias the yoke and the retainer in opposite directions, with the biasing member being configured to prevent free play of the yoke and the valve member with respect to said housing.

An exhaust gas control valve for regulating a flow of exhaust gas includes a housing having an interior wall defining a housing interior, a yoke disposed in the housing interior and having a length and an axis extending along the length, with the yoke being moveable between a first and second yoke position. The exhaust gas control valve further includes a valve member including a valve shaft and a valve body. The valve member is moveable between a first valve position and a second valve position. The exhaust gas control valve also includes a retainer coupled to the yoke, and a biasing member disposed in the housing interior and coupled to the yoke and the retainer to bias the yoke and the retainer in opposite directions, with the biasing member being configured to prevent free play of the yoke and the valve member with respect to said housing.

In accordance with one aspect of the present disclosure, a turbocharger includes a compressor having a compressor wheel, a turbine provided within a housing, and an exhaust gas recirculation (EGR) flow path. The EGR flow path includes a first fluid connection in the housing and located in proximity to the turbine, a second fluid connection located in proximity to a trailing edge of the compressor wheel, an EGR control valve disposed between the first fluid connection and the second fluid connection, the EGR control valve configured to selectively operate the turbocharger in a low-heat mode having an EGR up to 50% and an operational mode having an EGR rate typically less than 35%.

An engine system includes a throttle device, an EGR valve, and an ECU. The ECU diagnoses foreign-matter lodging abnormality of the EGR valve and the foreign-matter diameter based on intake pressure. When the existence of the abnormality and the foreign-matter diameter are determined, the ECU calculates a difference between a foreign-matter diameter and a predetermined learning determination value as a foreign-matter diameter difference. If this difference is larger than an abnormality determination value, the foreign-matter diameter is judged to be excessive and the throttle device is controlled to avoid engine stall. If the foreign-matter diameter difference is equal to or larger than a normality determination value and also equal to or less than the abnormality determination value, engine deceleration is continued. If the foreign-matter diameter difference is less than the normality determination value, the foreign-matter diameter is judged to be minute and the learning determination value is updated.

An engine system includes an injector, an EGR device (including an EGR valve having a step motor) to recirculate part of exhaust gas of an engine as EGR gas to the engine, and an electronic control unit (ECU) to control the injector, the EGR valve, and others based on an operating state of the engine. The ECU is configured to diagnose foreign-matter lodging abnormality of the EGR valve and a lodged foreign-matter diameter based on detected intake pressure during engine deceleration. When existence of the abnormality and the foreign-matter diameter are determined, the ECU controls the step motor to hold the EGR valve at a first opening degree smaller than a second opening degree needed to remove a foreign matter before fuel cut to the engine by the injector.

In accordance with one aspect of the present disclosure, a turbocharger includes a compressor having a compressor wheel, a turbine provided within a housing, and an exhaust gas recirculation (EGR) flow path. The EGR flow path includes a first fluid connection in the housing and located in proximity to the turbine, a second fluid connection located in proximity to a trailing edge of the compressor wheel, an EGR control valve disposed between the first fluid connection and the second fluid connection, the EGR control valve configured to selectively operate the turbocharger in a low-heat mode having an EGR up to 50% and an operational mode having an EGR rate typically less than 35%.

A valve includes a valve body having an exhaust gas inlet and an exhaust gas outlet, the valve body defining an exhaust gas circulation passage between the exhaust gas inlet and the exhaust gas outlet. A flap is arranged in the valve body and a shaft drives the flap in rotation with respect to the valve body. At least one guide bearing guides the drive shaft of the flap for rotation relative to the valve body. The guide bearing is engaged through an orifice of the valve body, with an inner end of the guide bearing being located inside the valve body. A first tube is engaged in one of the exhaust gas inlet and exhaust gas outlet and abuts against the inner end of the guide bearing.