Abstract: A cylinder head containing an exhaust system manifold for an engine includes screw holes formed through a fastening face of the cylinder head and an exhaust pipe, and outlet cooling channels that are provided adjacent to an outlet of a confluence of the manifold, and are disposed between the screw holes and the outlet. Coolant flows through the outlet cooling channels.

Abstract: A cylinder head containing an exhaust system manifold for an engine includes screw holes formed through a fastening face of the cylinder head and an exhaust pipe, and outlet cooling channels that are provided adjacent to an outlet of a confluence of the manifold, and are disposed between the screw holes and the outlet. Coolant flows through the outlet cooling channels.

Abstract: A cylinder head includes: a bottom wall; an outer circumferential wall defining inside thereof a disposition space where valves which open and close combustion chambers, rocker arms, a camshaft which actuates the rocker arms, and a rocker arm shaft which supports the rocker arms are disposed; a longitudinal; a lateral wall, integrally formed with the longitudinal wall and the outer circumferential wall; a camshaft support, formed on the lateral wall; a rocker arm shaft support, formed on the lateral wall in such a manner that a height of the rocker arm shaft is shifted from a height of the camshaft; and a head bolt boss, formed on the bottom wall to overlap the lateral wall in a height direction. The lateral wall includes a passage through which a head bolt is passed into the head bolt boss and which overlaps the head bolt boss in the height direction.

Abstract: A cylinder head includes: a bottom wall portion; an outer circumferential wall portion defining inside thereof a space; a longitudinal wall portion extending to define, in the space, an intake side where an intake camshaft is disposed and an exhaust side where an exhaust camshaft is disposed; first lateral wall portions disposed on the intake side, on which first support portions are formed for supporting the intake camshaft thereon; second lateral wall portions disposed on the intake side, on which second support portions are formed for supporting the variable valve actuating units thereon; and third lateral wall portions disposed on the exhaust side, on which third support portions are formed for supporting the exhaust camshaft thereon. The second lateral wall portions are lower than the first lateral wall portions in a height direction from the bottom wall portion. The third lateral wall portions are higher than the second lateral wall portions in the height direction.

Abstract: A cylinder head includes: a bottom wall portion; an outer circumferential wall portion defining inside thereof a space; a longitudinal wall portion extending to define, in the space, an intake side where an intake camshaft is disposed and an exhaust side where an exhaust camshaft is disposed; first lateral wall portions disposed on the intake side, on which first support portions are formed for supporting the intake camshaft thereon; second lateral wall portions disposed on the intake side, on which second support portions are formed for supporting the variable valve actuating units thereon; and third lateral wall portions disposed on the exhaust side, on which third support portions are formed for supporting the exhaust camshaft thereon. The second lateral wall portions are lower than the first lateral wall portions in a height direction from the bottom wall portion. The third lateral wall portions are higher than the second lateral wall portions in the height direction.

Abstract: A cylinder head includes: a bottom wall portion; an outer circumferential wall portion defining inside thereof a disposition space where valves which open and close combustion chambers, rocker arms, a camshaft which actuates the rocker arms, and a rocker arm shaft which supports the rocker arms are disposed; a longitudinal wall portion; a lateral wall portion, integrally formed with the longitudinal wall portion and the outer circumferential wall portion; a camshaft support portion, formed on the lateral wall portion; a rocker arm shaft support portion, formed on the lateral wall portion in such a manner that a height position of the rocker arm shaft is shifted from a height position of the camshaft; and a head bolt boss portion, formed on the bottom wall portion in such a manner as to overlap the lateral wall portion in a height direction.

Abstract: A valve gear for an internal combustion engine capable of promptly switching the position of a piston in a rocker arm to thereby change the engine operating condition with a satisfactory response, even in a low rotation region in which an adequate amount of oil discharged from an oil pump cannot be expected. Depending on positions of pistons slidably fitted in low-speed and high-speed cylinder portions provided in an intake driven rocker arm, a low-speed or high-speed drive rocker arm is selectively operated to press a corresponding one of the pistons. The piston in the low-speed cylinder portion switched in a low rotation region is made smaller in diameter than the piston in the high-speed cylinder portion, to be enabled to be promptly switched.

Abstract: A valve gear with a cylinder suspending mechanism of an internal combustion engine, whose entire valve gear mechanism is downsized by efficiently arranging the configuration of the valve gear including the cylinder suspending mechanism. A low-speed drive rocker arm and a high-speed drive rocker arm are disposed in front and at the rear of an intake driven rocker arm so that pistons of low-speed and high-speed cylinder portions arranged side by side in the intake driven rocker arm may be pressed by operating operation arm portions extending from the respective drive rocker arms, to thereby arrange the low-speed and high-speed cylinder portions and the low-speed and high-speed drive rocker arms around the intake driven rocker arm to gather in one place.

Abstract: A valve gear with a cylinder suspending mechanism of an internal combustion engine, whose entire valve gear mechanism is downsized by efficiently arranging the configuration of the valve gear including the cylinder suspending mechanism. A low-speed drive rocker arm and a high-speed drive rocker arm are disposed in front and at the rear of an intake driven rocker arm so that pistons of low-speed and high-speed cylinder portions arranged side by side in the intake driven rocker arm may be pressed by operating operation arm portions extending from the respective drive rocker arms, to thereby arrange the low-speed and high-speed cylinder portions and the low-speed and high-speed drive rocker arms around the intake driven rocker arm to gather in one place.

Abstract: A valve gear for an internal combustion engine capable of promptly switching the position of a piston in a rocker arm to thereby change the engine operating condition with a satisfactory response, even in a low rotation region in which an adequate amount of oil discharged from an oil pump cannot be expected. Depending on positions of pistons slidably fitted in low-speed and high-speed cylinder portions provided in an intake driven rocker arm, a low-speed or high-speed drive rocker arm is selectively operated to press a corresponding one of the pistons. The piston in the low-speed cylinder portion switched in a low rotation region is made smaller in diameter than the piston in the high-speed cylinder portion, to be enabled to be promptly switched.

Abstract: A plurality of oil passages are formed in a shaft body of a rocker shaft, which partially constitutes a valve drive system of an internal combustion engine. A bolt hole is formed in the shaft body in such a manner as to substantially perpendicularly intersect the axis of the shaft body. A bush is fitted into the bolt hole in such a manner as to prevent the bolt hole from establishing communication between the plurality of oil passages. A bolt is fastened through the bush to thereby fix the rocker shaft on a cylinder head. This structure improves the support rigidity of the rocker shaft and the dynamic characteristics of the valve drive system, and reduces the number of components and the number of working man-hours.

Abstract: A plurality of oil passages are formed in a shaft body of a rocker shaft, which partially constitutes a valve drive system of an internal combustion engine. A bolt hole is formed in the shaft body in such a manner as to substantially perpendicularly intersect the axis of the shaft body. A bush is fitted into the bolt hole in such a manner as to prevent the bolt hole from establishing communication between the plurality of oil passages. A bolt is fastened through the bush to thereby fix the rocker shaft on a cylinder head. This structure improves the support rigidity of the rocker shaft and the dynamic characteristics of the valve drive system, and reduces the number of components and the number of working man-hours.