Abstract: A valve timing adjustment device includes a hydraulic oil control valve. The hydraulic oil control valve includes: an outer sleeve that is shaped in a tubular form and has a projection at an outer periphery of the outer sleeve; an inner sleeve that is located on an inner side of the outer sleeve; and a spool that is located at an inside of the inner sleeve. A reference-shape portion, which serves as a reference at a time of positioning the outer sleeve relative to the inner sleeve, is formed at an outer periphery of the projection. A seat surface of the projection, which fixes a vane rotor between the seat surface of the projection and an end portion of one of a drive shaft and a driven shaft, is shaped in a rotationally symmetric form that is rotationally symmetric around a rotational axis.

Abstract: A valve timing adjustment device includes a hydraulic oil control valve. The hydraulic oil control valve includes: an outer sleeve that is shaped in a tubular form and has a projection at an outer periphery of the outer sleeve; an inner sleeve that is located on an inner side of the outer sleeve; and a spool that is located at an inside of the inner sleeve. A reference-shape portion, which serves as a reference at a time of positioning the outer sleeve relative to the inner sleeve, is formed at an outer periphery of the projection. A seat surface of the projection, which fixes a vane rotor between the seat surface of the projection and an end portion of one of a drive shaft and a driven shaft, is shaped in a rotationally symmetric form that is rotationally symmetric around a rotational axis.

Abstract: A control system for an internal combustion engine has an intake valve, an exhaust valve, and an exhaust purifying catalyst that purifies exhaust gas after combustion of a fuel. During a fuel cut in which no fuel is supplied, a closing timing of the intake valve is controlled to a delayed angle side more than at a timing when the fuel is supplied and to a delayed angle side more than at a timing at a bottom dead center of an intake stroke, and an opening timing of the exhaust valve is controlled to an advanced angle side more than at the timing when the fuel is supplied and to an advanced angle side more than at the timing at the bottom dead center of an expansion stroke.

Abstract: A power transmission system transmits power from an internal combustion engine to a first and a second auxiliary device through an endless transmitting member. Prior to issuing of an engine start request, the first auxiliary device is actuated to move a tensioner pulley to a given position to increase the degree of tension of the endless transmitting member. The actuation of the first auxiliary device as an engine starter upon the issuing of the engine start request, therefore, enables a drive shaft of the engine to be rotated immediately within a required time to crank the engine. This achieves a quick start of the engine and results in a decrease in amount of time between the issuing of the engine start request and the actual start of the engine.

Abstract: A control system for an internal combustion engine has an intake valve, an exhaust valve, and an exhaust purifying catalyst that purifies exhaust gas after combustion of a fuel. During a fuel cut in which no fuel is supplied, a closing timing of the intake valve is controlled to a delayed angle side more than at a timing when the fuel is supplied and to a delayed angle side more than at a timing at a bottom dead center of an intake stroke, and an opening timing of the exhaust valve is controlled to an advanced angle side more than at the timing when the fuel is supplied and to an advanced angle side more than at the timing at the bottom dead center of an expansion stroke.

Abstract: A power transmission system transmits power from an internal combustion engine to a first and a second auxiliary device through an endless transmitting member. Prior to issuing of an engine start request, the first auxiliary device is actuated to move a tensioner pulley to a given position to increase the degree of tension of the endless transmitting member. The actuation of the first auxiliary device as an engine starter upon the issuing of the engine start request, therefore, enables a drive shaft of the engine to be rotated immediately within a required time to crank the engine. This achieves a quick start of the engine and results in a decrease in amount of time between the issuing of the engine start request and the actual start of the engine.