Abstract: An angle detection mechanism to detect a rotation angle of a rotation body includes a first detection unit to cause a first output value to constantly change in response to an angle change of the rotation body in the entire region of a specific rotation range and to set a change quantity of the first output value relative to the angle change in a first rotation region of the specific rotation range to be greater than a change quantity in a non-first rotation region, and a second detection unit to cause a second output value to constantly change in response to an angle change and to set a change quantity of the second output value in a second rotation region including a rotation region different from the first rotation region to be greater than a change quantity in a non-second rotation region.

Abstract: A fixing shaft portion of a valve shaft is fixed to a throttle valve at first and second locations by first and second fixing members. A first bearing includes an inner race fixed to a first rotatable shaft portion of the valve shaft, and an outer race fixed to a valve body. A second bearing includes a slidable portion axially slidably fitted to a second rotatable shaft portion of the valve shaft and a fixing portion fixed to the valve body. A linear expansion coefficient of the throttle valve and a linear expansion coefficient of the valve body are set to be larger than a linear expansion coefficient of the valve shaft in an axial direction. A first distance measured from a center point of the throttle valve to the first location is larger than a second distance measured from the center point to the second location.

Abstract: An opening degree sensor produces a sensor output corresponding to a valve opening degree of a valve, and includes a memory into which the sensor output corresponding to the valve opening degree is written. When performing a first half process, flow rates of more than one valve device are measured, a flow rate error is calculated based on an average flow rate obtained by averaging the measured flow rates, and the sensor output corresponding to the valve opening degree into which the flow rate error is incorporated is obtained. When performing a second half process, the sensor output corresponding to the valve opening degree obtained in the first half process is written into the memory of the valve device whose flow rate is not measured.

Abstract: A low pressure EGR regulating valve is driven by an electric actuator, and an output of the electric actuator is transmitted to an intake air throttle valve through a link device. An ECU executes a failure determination to determine presence of a failure in a case where a sensed opening degree, which is sensed with a low pressure EGR opening degree sensor, is other than an opening degree that corresponds to a maximum opening degree of the throttle valve limited by a mechanical stopper. The ECU executes the failure determination after the energization of the electric actuator is stopped in response to stopping of the engine.

Abstract: A control device executes a feedback control operation of an electric motor such that a sensed opening degree of a valve approaches a target opening degree, which is set for a time of fully closing the valve. The control device stops the energization of the electric motor after reaching of the sensed opening degree of the valve to an energization stop opening degree, which is set on a valve opening side of a full closing degree of the valve in a valve opening direction of the valve. A return spring urges the valve in a valve closing direction of the valve. The target opening degree is set on a valve closing side of the energization stop opening degree in the valve closing direction.

Abstract: A control unit generates a control signal for controlling an actuator to manipulate a valve element and to control a quantity of flow in a passage according to both an opening position of the valve element and a predetermined correlation between the opening position and the quantity of flow. The control unit includes a storage unit storing an error-characteristic function and a compensation unit to compensate the control signal according to the error-characteristic function. An actual correlation between the opening position and the quantity of flow is actually measured separately from the predetermined correlation. The error-characteristic function is an approximation of a relation between an opening position x in the predetermined correlation and an opening position y in the actual correlation at a same quantity of flow, which are calculated beforehand with reference to the actual correlation and the predetermined correlation.

Abstract: A control unit generates a control signal for controlling an actuator to manipulate a valve element and to control a quantity of flow in a passage according to both an opening position of the valve element and a predetermined correlation between the opening position and the quantity of flow. The control unit includes a storage unit storing an error-characteristic function and a compensation unit to compensate the control signal according to the error-characteristic function. An actual correlation between the opening position and the quantity of flow is actually measured separately from the predetermined correlation. The error-characteristic function is an approximation of a relation between an opening position x in the predetermined correlation and an opening position y in the actual correlation at a same quantity of flow, which are calculated beforehand with reference to the actual correlation and the predetermined correlation.

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: 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: 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: 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: 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 includes a housing having a seat ring and a plate spring, a butterfly valve, and a valve shaft. The valve shaft has a plane-surface portion and a cam portion, which are arranged adjacent to each other. The fluid control valve is configured such that when an opening degree of the butterfly valve is a first valve opening degree or more, the cam portion is brought into sliding contact with the seat ring and the seat ring is pushed to a location radially outward of a moving path of the butterfly valve against elastic force of the plate spring. Thus, occurrence of uneven wear on a seat surface of the seat ring can be suppressed.

Abstract: A low pressure EGR regulating valve is driven by an electric actuator, and an output of the electric actuator is transmitted to an intake air throttle valve through a link device. An ECU executes a failure determination to determine presence of a failure in a case where a sensed opening degree, which is sensed with a low pressure EGR opening degree sensor, is other than an opening degree that corresponds to a maximum opening degree of the throttle valve limited by a mechanical stopper. The ECU executes the failure determination after the energization of the electric actuator is stopped in response to stopping of the engine.

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.