An engine includes a combustion chamber, a cylinder head, an intake valve, a partition wall plate, and a tumble valve. The cylinder head includes an intake port that communicates with the combustion chamber. The intake valve includes a head configured to open and close an open end of the intake port. The partition wall plate partitions the intake port into first and second passages. The tumble valve is configured to open and close either one of the first passage and the second passage. A cross sectional shape of the partition wall plate is defined on a basis of a shape of a gap that is surrounded by a contour of the head and a contour of the open end, as viewed in a reference direction. The reference direction is a direction from a reference point in the intake port to a gap between the open end and the head.

An engine includes a combustion chamber, a cylinder head, an intake valve, a partition wall plate, and a tumble valve. The cylinder head includes an intake port that communicates with the combustion chamber. The intake valve includes a head configured to open and close an open end of the intake port. The partition wall plate partitions the intake port into first and second passages. The tumble valve is configured to open and close either one of the first passage and the second passage. A cross sectional shape of the partition wall plate is defined on a basis of a shape of a gap that is surrounded by a contour of the head and a contour of the open end, as viewed in a reference direction. The reference direction is a direction from a reference point in the intake port to a gap between the open end and the head.

An assembly structure of a nonmagnetic member to which a position sensor arranged to to sense a rotation position of the rotation member, includes: a nonmagnetic member including a hollow portion; a cover which is fixed to an opening end portion of the hollow portion; and a retaining portion which is provided on an outer circumference portion of the hollow portion of the nonmagnetic member, and to which the position sensor is assembled from the opening end portion's side to be slid in a rotation axis direction, the cover restricting movements of the magnet holding portion and the position sensor in the rotation axis direction in a case where the cover is fixed to the nonmagnetic member in a state where the magnet holding portion and the position sensor are assembled to the nonmagnetic member.

An assembly structure of a nonmagnetic member to which a position sensor arranged to to sense a rotation position of the rotation member, includes: a nonmagnetic member including a hollow portion; a cover which is fixed to an opening end portion of the hollow portion; and a retaining portion which is provided on an outer circumference portion of the hollow portion of the nonmagnetic member, and to which the position sensor is assembled from the opening end portion's side to be slid in a rotation axis direction, the cover restricting movements of the magnet holding portion and the position sensor in the rotation axis direction in a case where the cover is fixed to the nonmagnetic member in a state where the magnet holding portion and the position sensor are assembled to the nonmagnetic member.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a target combustion condition. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition via a feedback control with a gain. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to determine the gain so as to increase as the fuel ratio decreases.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a target combustion condition. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition via a feedback control with a gain. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to determine the gain so as to increase as the fuel ratio decreases.

In an electric actuator, one end portion of a return spring is hooked to a first slit formed in a radially outer guide of an output gear, so that the return spring is twisted for a predetermined angle that is slightly smaller than an initial set angle. A tilted slit portion is formed at an opening of a second slit that is formed in a covering wall of a spring installation member to twist the return spring to a predetermined initial set angle. Thereby, simultaneously with assembling of a valve shaft to the output gear, the return spring is twisted for the initial set angle. Thus, an assembling work of the electric actuator can be simplified.

In an electric actuator, one end portion of a return spring is hooked to a first slit formed in a radially outer guide of an output gear, so that the return spring is twisted for a predetermined angle that is slightly smaller than an initial set angle. A tilted slit portion is formed at an opening of a second slit that is formed in a covering wall of a spring installation member to twist the return spring to a predetermined initial set angle. Thereby, simultaneously with assembling of a valve shaft to the output gear, the return spring is twisted for the initial set angle. Thus, an assembling work of the electric actuator can be simplified.

Methods and systems are provided for introducing a charge motion to a cylinder via a bladder in an intake manifold runner. In one example, a system may include positioning a bladder in an intake port proximate to a cylinder.

Methods and systems are provided for introducing a charge motion to a cylinder via a bladder in an intake manifold runner. In one example, a system may include positioning a bladder in an intake port proximate to a cylinder.