Abstract: A map creating method for nozzle vanes includes performing an imbalance operation as many times as the number of the cylinders while changing the specific cylinder, creating air-fuel ratio data indicating changes in the air-fuel ratio during the imbalance operation, calculating an air-fuel ratio fluctuation amount for each of pieces of the air-fuel ratio data, determining whether a specific condition is met, the specific condition being that a minimum value among the air-fuel ratio fluctuation amounts is greater than or equal to a first determination value and a difference between the minimum value and a maximum value among the air-fuel ratio fluctuation amounts is less than or equal to a second determination value, and storing, as an opening degree map, the opening degree of the nozzle vanes meeting the specific condition in association with the engine operating state.

Abstract: A forced-induction device includes a turbine wheel, a turbine housing, and a connection pipe. The connection pipe includes a partition wall that partitions the inside of the connection pipe into a first passage and a second passage. When a cross section orthogonal to a rotation axis of the turbine wheel is viewed, a line segment extending from the distal end of the partition wall toward the upstream side in the flow direction of exhaust gas and defining a boundary between the first passage and the partition wall is a first downstream line segment. A line segment extending from the distal end of the partition wall toward the upstream side in the flow direction of exhaust gas and defining a boundary between the second passage and the partition wall is a second downstream line segment. The first downstream line segment and the second downstream line segment are parallel to each other.

Abstract: An internal combustion engine includes a turbocharger and an upstream pipe. The turbocharger includes a compressor housing and a compressor wheel. The compressor wheel includes main blades and a shaft. The shaft extends parallel to the rotation axis of the compressor wheel. The main blades each project from the shaft in a direction orthogonal to the rotation axis. The main blades are spaced apart from one another in the circumferential direction. The upstream pipe includes a tubular member and guide vanes. The guide vanes each project from the inner wall surface of the tubular member. The guide vanes are spaced apart from one another in the circumferential direction. The number of the guide vanes is a prime number greater than two times the number of the main blades.

Abstract: A forced-induction device includes a turbine wheel and a partition wall that partitions the interior of a connection pipe into a first passage and a second passage. When viewed in a cross section orthogonal to a rotation axis of the turbine wheel, a line segment connecting the rotation center of the turbine wheel and a downstream end of an inner wall in a flow direction of exhaust gas is a first line segment. A straight line orthogonal to the first line segment and extending from the downstream end in the flow direction of the exhaust gas is a first imaginary line. A straight line passing through a proximal end of the partition wall and orthogonal to an inflow direction of the exhaust gas is a second imaginary line. The distal end of the partition wall is located between the first imaginary line and the second imaginary line.

Abstract: A forced-induction device includes a turbine wheel, a turbine housing, and a connection pipe. The connection pipe includes a partition wall that partitions the inside of the connection pipe into a first passage and a second passage. When a cross section orthogonal to a rotation axis of the turbine wheel is viewed, a line segment extending from the distal end of the partition wall toward the upstream side in the flow direction of exhaust gas and defining a boundary between the first passage and the partition wall is a first downstream line segment. A line segment extending from the distal end of the partition wall toward the upstream side in the flow direction of exhaust gas and defining a boundary between the second passage and the partition wall is a second downstream line segment. The first downstream line segment and the second downstream line segment are parallel to each other.

Abstract: A forced-induction device includes a turbine wheel and a partition wall that partitions the interior of a connection pipe into a first passage and a second passage. When viewed in a cross section orthogonal to a rotation axis of the turbine wheel, a line segment connecting the rotation center of the turbine wheel and a downstream end of an inner wall in a flow direction of exhaust gas is a first line segment. A straight line orthogonal to the first line segment and extending from the downstream end in the flow direction of the exhaust gas is a first imaginary line. A straight line passing through a proximal end of the partition wall and orthogonal to an inflow direction of the exhaust gas is a second imaginary line. The distal end of the partition wall is located between the first imaginary line and the second imaginary line.

Abstract: A turbocharger includes a turbine wheel, a turbine housing, a bearing housing, a compressor housing, a seal plate, a variable nozzle mechanism, a penetrating shaft, and a spring member. The variable nozzle mechanism is located within the turbine housing, and adjusts the amount of exhaust gas that flows toward the turbine wheel. The penetrating shaft extends through the bearing housing and is connected to the variable nozzle mechanism. The spring member pushes out the penetrating shaft toward the compressor housing. The bearing housing and the seal plate define a cooling chamber through which coolant flows. The spring member is located in the cooling chamber.

Abstract: A turbocharger includes a turbine wheel, a turbine housing, a bearing housing, a compressor housing, a seal plate, a variable nozzle mechanism, a penetrating shaft, and a spring member. The variable nozzle mechanism is located within the turbine housing, and adjusts the amount of exhaust gas that flows toward the turbine wheel. The penetrating shaft extends through the bearing housing and is connected to the variable nozzle mechanism. The spring member pushes out the penetrating shaft toward the compressor housing. The bearing housing and the seal plate define a cooling chamber through which coolant flows. The spring member is located in the cooling chamber.

Abstract: A turbocharger includes a compressor housing, a turbine housing, a bearing housing, a variable nozzle unit, and a fixing member. The variable nozzle unit includes a first plate, a second plate, a plurality of nozzle vanes, and an attitude changing mechanism. The fixing member includes an engagement portion that is engaged with at least one of the first plate and the second plate, a through shaft portion shaped to extend through the bearing housing toward the compressor housing, and a fixing portion that fixes an end portion of the through shaft portion on the compressor housing side to the hearing housing.

Abstract: A turbocharger includes a compressor housing, a turbine housing, a bearing housing, a variable nozzle unit, and a fixing member. The variable nozzle unit includes a first plate, a second plate, a plurality of nozzle vanes, and an attitude changing mechanism. The fixing member includes an engagement portion that is engaged with at least one of the first plate and the second plate, a through shaft portion shaped to extend through the bearing housing toward the compressor housing, and a fixing portion that fixes an end portion of the through shaft portion on the compressor housing side to the hearing housing.

Abstract: A V-clamp fastens a clamping flange of a turbine housing and a clamping flange of a bearing housing in a rotation axis direction of a connecting shaft so that the clamping flanges are fixed to each other. An annular heat shield plate is disposed between the turbine housing and the bearing housing. The heat shield plate is clamped by the turbine housing and the bearing housing. A clearance is disposed in an entire area between an opposed surface of the clamping flange of the turbine housing and an opposed surface of the clamping flange of the bearing housing.

Abstract: A V-clamp fastens a clamping flange of a turbine housing and a clamping flange of a bearing housing in a rotation axis direction of a connecting shaft so that the clamping flanges are fixed to each other. An annular heat shield plate is disposed between the turbine housing and the bearing housing. The heat shield plate is clamped by the turbine housing and the bearing housing. A clearance is disposed in an entire area between an opposed surface of the clamping flange of the turbine housing and an opposed surface of the clamping flange of the bearing housing.

Abstract: A compressor wheel includes a shaft portion, which extends in the rotation axis direction of the compressor wheel. Blades protrude in the radial direction from the shaft portion. The blades are spaced apart from each other in the circumferential direction of the compressor wheel. The compressor housing has an accommodation space that accommodates the compressor wheel. The compressor housing also has an introduction passage defined therein. The introduction passage is connected to the accommodation space from the intake side and introduces intake air into the accommodation space. Plate-shaped guide vanes protrude from the inner wall surface of the introduction passage. The guide vanes are spaced apart from each other in the circumferential direction of the introduction passage. The number of the guide vanes is the smallest odd number that is greater than the number of the blades.

Abstract: A vehicle forced-induction device includes a first exhaust turbine type forced-induction unit and a second exhaust turbine type forced-induction unit. The first forced-induction unit includes an outlet pipe. The outlet pipe includes a first tubular portion and an annular first flange. The second forced-induction unit includes an inlet pipe. The inlet pipe includes a second tubular portion and an annular second flange. The forced-induction device includes a fastener that includes an annular groove. The annular groove has a shape in which a width of the annular groove decreases toward a groove bottom. The fastener is wound around the first and second flanges along a circumference of the first and the second flanges, thereby housing the first and second flanges in the annular groove. The fastener fastens the first and second flanges to urge the first and second flanges toward each other.

Abstract: A turbocharger impeller is provided with a hub portion with a plurality of vane portions extending outwardly thereof. The hub portion is substantially shaped as a truncated cone with a diameter that gradually increases along a rotation axis. The vane portions are formed on a surface of the hub portion and guide a fluid flowing along the rotation axis radially outward relative to the hub portion. Grooves are formed in and/or on surfaces of the vane portions along a direction of the fluid flowing radially outward during rotation of the impeller. Protruding crest portions are formed between adjacent grooves. Crest portions in a central region near the rotation axis are lower in height than crest portions in an outer region further away from the rotation axis.

Abstract: A vehicle forced-induction device includes a first exhaust turbine type forced-induction unit and a second exhaust turbine type forced-induction unit. The first forced-induction unit includes an outlet pipe. The outlet pipe includes a first tubular portion and an annular first flange. The second forced-induction unit includes an inlet pipe. The inlet pipe includes a second tubular portion and an annular second flange. The forced-induction device includes a fastener that includes an annular groove. The annular groove has a shape in which a width of the annular groove decreases toward a groove bottom. The fastener is wound around the first and second flanges along a circumference of the first and the second flanges, thereby housing the first and second flanges in the annular groove. The fastener fastens the first and second flanges to urge the first and second flanges toward each other.

Abstract: A turbocharger impeller is provided with a hub portion with a plurality of vane portions extending outwardly thereof. The hub portion is substantially shaped as a truncated cone with a diameter that gradually increases along a rotation axis. The vane portions are formed on a surface of the hub portion and guide a fluid flowing along the rotation axis radially outward relative to the hub portion. Grooves are formed in and/or on surfaces of the vane portions along a direction of the fluid flowing radially outward during rotation of the impeller. Protruding crest portions are formed between adjacent grooves. Crest portions in a central region near the rotation axis are lower in height than crest portions in an outer region further away from the rotation axis.

Abstract: An internal combustion engine includes: an exhaust heat collector, in which exhaust gas exchanges heat with engine coolant, that heats the engine coolant; an EGR mechanism that recirculates a part of the exhaust gas to an intake passage through an EGR passage that branches from an exhaust passage; and an EGR cooler that cools the exhaust gas flowing through the EGR passage through heat exchange with the engine coolant supplied from the exhaust heat collector.

Abstract: A variable capacity supercharger for an internal combustion engine is provided with a turbine having an exhaust-side movable vane mechanism for changing the cross-sectional area of a flow path of exhaust gas introduced into a turbine wheel by open-close operation of a movable vane, a compressor having an intake-side movable vane mechanism for changing the cross-sectional area of a flow path of intake air delivered from a compressor wheel by open-close operation of a movable vane, and a drive mechanism having an actuator used in common by the exhaust-side movable vane mechanism and the intake-side movable vane mechanism to perform open-close operation of the movable vane of each movable vane mechanism as transmitting operation of the actuator to both of the movable vane mechanisms.

Abstract: A gas introducing structure of an intake path includes a gas introducing path introducing a gas into an intake airflow in the intake path of an internal combustion engine, wherein an inner peripheral surface of the gas introducing path is made of a bottom surface appearing as a straight line at a lower side of a perpendicular cross section of the inner peripheral surface and a curved wall surface appearing as a convex curved line, connecting with each end of the straight line at an angle, at an upper side of the perpendicular cross section of the inner peripheral surface.