Abstract: Disclosed is a control device for a multi-cylinder engine having a combustion chamber (19) to which an intake port (16) and an exhaust port (17) are connected. The control device comprises: an intake-side variable valve operating mechanism (71) for controlling a lift timing of two intake valves (21a, 21b) of the intake port (16); an exhaust-side variable valve operating mechanism (72) for controlling a lift timing of an exhaust valve (22a); and an exhaust-side valve operating mechanism (73) for driving an exhaust valve (22b) at a fixed timing. The control device is operable, when executing cylinder deactivation in a low engine load and low engine speed operating range, to cause the exhaust-side variable valve operating mechanism (72) to open the exhaust valve (22a) during downward movement of a piston (14) in a cylinder (18) being subjected to the cylinder deactivation.

Abstract: Disclosed is a control device for a multi-cylinder engine having a combustion chamber (19) to which an intake port (16) and an exhaust port (17) are connected. The control device comprises: an intake-side variable valve operating mechanism (71) for controlling a lift timing of two intake valves (21a, 21b) of the intake port (16); an exhaust-side variable valve operating mechanism (72) for controlling a lift timing of an exhaust valve (22a); and an exhaust-side valve operating mechanism (73) for driving an exhaust valve (22b) at a fixed timing. The control device is operable, when executing cylinder deactivation in a low engine load and low engine speed operating range, to cause the exhaust-side variable valve operating mechanism (72) to open the exhaust valve (22a) during downward movement of a piston (14) in a cylinder (18) being subjected to the cylinder deactivation.

Abstract: A valve train device for an engine includes: a shaft portion; a cam element portion which is mounted on the shaft portion; and an operation member. The cam element portion includes a first end surface cam and a second end surface cam. Each of the first end surface cam and the second end surface cam includes a lift portion. The operation member includes a first operation member and a second operation member. The first operation member causes the cam element portion to move in a first direction, and the second operation member causes the cam element portion to move in a second direction. The first end surface cam includes a first slope portion, and guides the first operation member radially outwardly; and a displacement allowing portion which is formed adjacent to the first slope portion, and allows relative displacement between the first operation member, and the cam element portion.

Abstract: A valve train device for an engine includes: a shaft portion; a cam element portion which is mounted on the shaft portion; and an operation member. The cam element portion includes a first end surface cam and a second end surface cam. Each of the first end surface cam and the second end surface cam includes a lift portion. The operation member includes a first operation member and a second operation member. The first operation member causes the cam element portion to move in a first direction, and the second operation member causes the cam element portion to move in a second direction. The first end surface cam includes a first slope portion, and guides the first operation member radially outwardly; and a displacement allowing portion which is formed adjacent to the first slope portion, and allows relative displacement between the first operation member, and the cam element portion.

Abstract: A cam element portions is configured such that respective maximum lift portions (lift ending points) of both-side end-face cams thereof are provided at respective phases which are different from each other in a rotational direction and that a maximum value of a length, in an axial direction, between respective cam faces of the both-side end-face cams which are provided at the same phase is set to be a distance, in the axial direction, between a first operational member and a second operational member or smaller. Accordingly, in a valve gear of an engine in which cams operative to control opening/closing of a valve are switchable, it can be properly prevented that a camshaft locks and stop rotating because of an operational malfunction of an operational member or the like.

Abstract: A valve operating system for an engine is provided. The system includes first and second detent mechanisms for holding a cam element at a first position when the cam element is shifted to one side in camshaft directions, and at a second position when the cam element is shifted to the other side. The detent mechanisms include first and second detent cams and first and second pushing members, respectively. The first detent cam includes first and second grooves and a first top portion. The second detent cam includes third and fourth grooves and a second top portion. The first and second grooves have inclining portions extending from the first top portion toward bottoms thereof, inclining with respect to the camshaft directions, respectively. The third and fourth grooves have inclining portions extending from the second top portion toward bottoms thereof, inclining with respect to the camshaft directions, respectively.

Abstract: A cam element portion comprises a slant portion (reverse-rotation return slope portion), which is positioned on a rotary-delay side from a maximum-lift portion (lift ending point) of an end-face cam and slants inward toward the rotary-delay side from an outer peripheral face of the end-face cam. Accordingly, in a valve gear of an engine in which cams operative to control opening/closing of a valve are switchable, it can be properly prevented that the cam element portion is switched unexpectedly and improperly or an operational member breaks down which are possibly caused by an engine's reverse rotation.

Abstract: A valve operating system for an engine is provided. The system includes first and second detent mechanisms for holding a cam element at a first position when the cam element is shifted to one side in camshaft directions, and at a second position when the cam element is shifted to the other side. The detent mechanisms include first and second detent cams and first and second pushing members, respectively. The first detent cam includes first and second grooves and a first top portion. The second detent cam includes third and fourth grooves and a second top portion. The first and second grooves have inclining portions extending from the first top portion toward bottoms thereof, inclining with respect to the camshaft directions, respectively. The third and fourth grooves have inclining portions extending from the second top portion toward bottoms thereof, inclining with respect to the camshaft directions, respectively.

Abstract: A cam element portions is configured such that respective maximum lift portions (lift ending points) of both-side end-face cams thereof are provided at respective phases which are different from each other in a rotational direction and that a maximum value of a length, in an axial direction, between respective cam faces of the both-side end-face cams which are provided at the same phase is set to be a distance, in the axial direction, between a first operational member and a second operational member or smaller. Accordingly, in a valve gear of an engine in which cams operative to control opening/closing of a valve are switchable, it can be properly prevented that a camshaft locks and stop rotating because of an operational malfunction of an operational member or the like.

Abstract: A cam element portion comprises a slant portion (reverse-rotation return slope portion), which is positioned on a rotary-delay side from a maximum-lift portion (lift ending point) of an end-face cam and slants inward toward the rotary-delay side from an outer peripheral face of the end-face cam. Accordingly, in a valve gear of an engine in which cams operative to control opening/closing of a valve are switchable, it can be properly prevented that the cam element portion is switched unexpectedly and improperly or an operational member breaks down which are possibly caused by an engine's reverse rotation.