Abstract: In an upstream portion from a valve connecting surface that is formed in an opening of an intake port to a combustion chamber, an upper wall surface of the intake port continues from an upstream side end of the valve connecting surface and extends substantially straight and diagonally with respect to a ceiling surface on the intake port side. In addition, a cross-sectional shape of the portion in the intake port in a direction perpendicular to an axial direction of the intake port is a flat shape with an axis in a transverse direction being a long axis.

Abstract: Intake holes at the opposite ends are opened and closed by first intake valves. The middle intake hole is opened and closed by a second intake valve. A control device includes an intake variable valve device. First branch channels are connected to the intake holes and produce a normal tumble flow. A second branch channel is configured such that the flow rate of intake air passing through the middle intake hole is relatively greater on the side closer to the outer periphery of the combustion chamber. Where increasing the flow coefficient is given a higher priority, a three-valve drive mode is selected. Where the strength of the normal tumble flow is enhanced, a two-valve drive mode is selected. Where production of the normal tumble flow is reduced, a one-valve drive mode is selected.

Abstract: A fluid transfer apparatus includes a spiral pipe that is formed by an elastic tube wound in a spiral manner, and a fluid to be transferred flows in the spiral pipe. The fluid transfer apparatus further includes a speaker that is configured to generate a pressure wave in a working fluid in the tube that is a medium, and the pressure wave causes a change of the cross-sectional area of a flow channel of the tube.

Abstract: Intake holes at the opposite ends are opened and closed by first intake valves. The middle intake hole is opened and closed by a second intake valve. A control device includes an intake variable valve device. First branch channels are connected to the intake holes and produce a normal tumble flow. A second branch channel is configured such that the flow rate of intake air passing through the middle intake hole is relatively greater on the side closer to the outer periphery of the combustion chamber. Where increasing the flow coefficient is given a higher priority, a three-valve drive mode is selected. Where the strength of the normal tumble flow is enhanced, a two-valve drive mode is selected. Where production of the normal tumble flow is reduced, a one-valve drive mode is selected.

Abstract: With regard to an internal combustion engine having a tumble flow formed in a cylinder, an object of the invention is to intensify the tumble flow. There is provided an internal combustion engine having a pent-roof type combustion chamber. In a predetermined area in the vicinity of an opening of an intake port to a combustion chamber, an upper wall surface of the intake port is extended approximately linearly while being inclined to an intake port-side ceiling surface more downward than a normal direction of the intake port-side ceiling surface in a side view. In a partial area in the predetermined area of the intake port, a distance between lateral wall surfaces on a left side and on a right side of the intake port is gradually increased toward downstream in a top view.

Abstract: In an upstream portion from a valve connecting surface that is formed in an opening of an intake port to a combustion chamber, an upper wall surface of the intake port continues from an upstream side end of the valve connecting surface and extends substantially straight and diagonally with respect to a ceiling surface on the intake port side. In addition, a cross-sectional shape of the portion in the intake port in a direction perpendicular to an axial direction of the intake port is a flat shape with an axis in a transverse direction being a long axis.

Abstract: A fluid transfer apparatus includes a spiral pipe that is formed by an elastic tube wound in a spiral manner, and a fluid to be transferred flows in the spiral pipe. The fluid transfer apparatus further includes a speaker that is configured to generate a pressure wave in a working fluid in the tube that is a medium, and the pressure wave causes a change of the cross-sectional area of a flow channel of the tube.

Abstract: With regard to an internal combustion engine having a tumble flow formed in a cylinder, an object of the invention is to intensify the tumble flow. There is provided an internal combustion engine having a pent-roof type combustion chamber. In a predetermined area in the vicinity of an opening of an intake port to a combustion chamber, an upper wall surface of the intake port is extended approximately linearly while being inclined to an intake port-side ceiling surface more downward than a normal direction of the intake port-side ceiling surface in a side view. In a partial area in the predetermined area of the intake port, a distance between lateral wall surfaces on a left side and on a right side of the intake port is gradually increased toward downstream in a top view.

Abstract: Disclosed is a piston (16) that is capable of not only suppressing the occurrence of knocking but also reducing cooling loss in an internal combustion engine in which a tumble flow is formed in a cylinder. The piston for the internal combustion engine in which the tumble flow is formed in the cylinder includes a non-adiabatic region (50) that is a region on a piston upper surface (35) brought into contact with the tumble flow during an intake stroke and has no insulating layer. The piston also includes an adiabatic region (52) that is a region on at least a part of the piston upper surface excluding the non-adiabatic region and has an insulating layer.

Abstract: Disclosed is a piston (16) that is capable of not only suppressing the occurrence of knocking but also reducing cooling loss in an internal combustion engine in which a tumble flow is formed in a cylinder. The piston for the internal combustion engine in which the tumble flow is formed in the cylinder includes a non-adiabatic region (50) that is a region on a piston upper surface (35) brought into contact with the tumble flow during an intake stroke and has no insulating layer. The piston also includes an adiabatic region (52) that is a region on at least a part of the piston upper surface excluding the non-adiabatic region and has an insulating layer.