Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Mitsubishi Jidosha Engineering Kabushiki Kaisha

Kenichi Morishima

Toshihiko Oka

Norio Takayasu

Keisuke Komura

Tetsushi Nagira

Koichi Yoshimoto

Satoshi Matsui

Yoshinori Sakurai

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.

Cylinder head

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. A face of the bottom wall portion which is disposed on the exhaust side is higher than a face of the bottom wall portion which is disposed on the intake side, in the height direction.

The bottom surfaceof the cylinder headis formed by an intake-side bottom surfaceand an exhaust-side bottom surfaceon which an intake portand an exhaust portare formed respectively. Further, a first wallformed between an intake-side water jacketand the intake-side bottom surfaceis larger in thickness than a second wallformed between an exhaust-side water jacketand the exhaust-side bottom surface. This structure can reduce an amount of HC included in exhaust gas.

Cylinder head structure

Growing community of inventors

Okazaki, Japan

Kenichi Morishima