Abstract: An object of the invention for a valve device having an inclined valve body is to suppress pressure loss at a valve opened condition to a smaller amount. The valve body is composed of a disc shaped valve member for closing a fluid passage, a first supporting portion provided at an outer periphery of the valve member and connected to a first shaft member, and a second supporting portion provided at another outer periphery of the valve member and connected to a second shaft member. The valve body is formed of a press-molded metal plate and forms a Z-shape when viewed in a direction parallel to a surface of the valve member.

Abstract: A converting mechanism is provided between an EGR control valve driven by an actuator and an intake-air valve for generating negative pressure, so that the intake-air valve is also driven by the actuator. The converting mechanism has a cam plate rotated together with the EGR control valve and an arm rotated together with the intake-air valve. A cam groove formed in the cam plate is engaged with a driving pin of the arm. The intake-air valve is held at its maximum valve opening position, when the EGR control valve is rotated in a first angular range, while the intake-air valve is rotated from the valve opening position to a maximum valve closing position when the EGR control valve is rotated in a second angular range.

Abstract: An EGR control valve is driven by an actuator so as to control EGR amount by changing its opening degree. An EGR cooling device is provided in an EGR passage for cooling down EGR gas. A bypass passage is provided to the EGR passage, so that EGR gas may bypass the EGR cooling device. A switching valve is provided in the EGR passage for switching EGR mode from a hot EGR mode in which the EGR gas flows through the bypass passage to a cold EGR mode in which the EGR gas flows through the EGR cooling device, or vice versa. A converting mechanism is provided between the EGR control valve and the switching valve, so that the switching valve is driven by the actuator from its hot to cold switching position (or vice versa) when the EGR control valve is driven by the same actuator in a small angular range.

Abstract: An actuator includes an electric motor and a drive force transmitting mechanism. The drive force transmitting mechanism includes a rotary gear and a rotary cam. The rotary gear transmits a drive force of the electric motor to an EGR valve to drive the same. The rotary cam transmits the drive force of the electric motor to a mode change valve to drive the same. The rotary cam is releasably linkable to the rotary gear to receive the drive force of the electric motor through the rotary gear.

Abstract: A partition wall partitioning a cooler inlet port and a cooler outlet port extends from a cooler connecting surface of a connecting portion to a vicinity of a shaft supporting a four-way butterfly valve. An EGR gas leakage around a first valve plate can be restricted. Thus, an increase in temperature of EGR gas flowing through an EGR gas outlet port can be restricted at a cooled mode. A deterioration of emission reducing performance can be avoided.

Abstract: When a control unit variably controls an electric power supplied to an electric motor to repeat a valve opening and closing movement of a valve between a first intermediate position and a second intermediate position through a neutral position, the control unit initially sets the neutral position as a control target value until a valve position, which is sensed with a valve opening degree sensor, is located immediately before the neutral position. The control unit thereafter changes the control target value to the first intermediate position or the second intermediate position when the control unit determines that the valve position, which is sensed with the valve opening degree sensor, reaches the neutral position.

Abstract: A fluid control valve assembly is disclosed that includes a housing, a valve with a ring-shaped groove, and a seal ring with a clearance extending between an outer diameter and an inner diameter. The seal ring includes a pair of opposing axial side surfaces and is provided in the groove. The seal ring seals against the housing when the valve is in the closed position. The valve assembly also includes a backup ring provided in the groove adjacent one of the axial side surfaces of the seal ring to thereby obstruct fluid flow through the clearance of the seal ring when the valve is in the closed position.

Abstract: An exhaust gas recirculation apparatus includes a housing connected with an EGR cooler via a mount face. The housing has a valve chamber accommodating a selector valve. The housing has a partition extending from the mount face close to the valve chamber to divide first and second exhaust ports opened in the mount face. A first passage leads exhaust gas into the EGR cooler through the valve chamber. A second passage recirculates exhaust gas to the intake passage through the EGR cooler and the valve chamber. A bypass passage leads exhaust gas from the engine through the valve chamber to bypass the EGR cooler. A rotation axis of the selector valve is perpendicular to an axis of the mount face, and offset away from the partition.

Abstract: A fluid control valve assembly is disclosed that includes a housing, a valve with a ring-shaped groove, and a seal ring with a clearance extending between an outer diameter and an inner diameter. The seal ring includes a pair of opposing axial side surfaces and is provided in the groove. The seal ring seals against the housing when the valve is in the closed position. The valve assembly also includes a backup ring provided in the groove adjacent one of the axial side surfaces of the seal ring to thereby obstruct fluid flow through the clearance of the seal ring when the valve is in the closed position.

Abstract: A first EGR pipe and a second EGR pipe are merged at a confluent portion. A three-way valve is disposed in the confluent portion to interrupt a communication between the first and the second EGR pipe. An EGR gas cooler is disposed upstream of EGR control valves. Exhaust gas pulsations in the first exhaust pipe and the second exhaust pipe do not interfere with each other even if the phase of the pulsations are quit opposite. Thus, the exhaust gas pressure working on turbines of turbocharger can be increased to enhance a supercharging efficiency.

Abstract: In a gas circulating apparatus, a bypass pipe extends in parallel with an EGR gas cooler. The aperture end of the bypass pipe is inserted to inside of a housing of a valve device and is positioned adjacent to a valve in the housing. Accordingly, the high-temperature EGR gas heat introduced to a second exhaust gas passage of the housing from the bypass pipe is difficult to be transmitted to a first exhaust gas passage of the housing. Thus, the heat transmission of the high-temperature EGR gas to the EGR gas cooler can be reduced.