Toyota Jidosha Kabushiki Kaisha

Tsutomu Wakiya

Akihiro Ikeda

Hideo Nakamura

A cylinder head with which exhaust manifolds are integrated includes a secondary air supply passage configured to include: a main passage disposed above combustion chambers of an engine, and extending along a cylinder line direction; and plural branch passages establishing individual communications between the main passage and corresponding exhaust ports. The respective plural branch passages are so disposed as to be inclined downward from the main passage toward the exhaust ports. Accordingly, it is possible to prevent corrosion of the cylinder head due to stagnation of condensed water.

Cylinder head and internal combustion engine

A cooling structure for a cylinder head, wherein the cylinder head has formed therein an exhaust manifold having branch sections and also having a collecting section to which the branch sections connect; a first water jacket and a second water jacket, which cover the exhaust manifold; connection passages which supply cooling water in the second water jacket to the first water jacket; and a cooling water outlet which connects the first water jacket to the outside. The connection passages include the first connection passage which is closest to the collecting section, and the second connection passage which is located at the downstream end of each of the water jackets. The flow passage cross-sectional area of the second connection passage is set to be less than the flow passage cross-sectional area of the first connection passage.

Cooling structure for cylinder head

A cylinder head () includes a water jacket () formed around an ignition plug mounting hole (). Upper surfaces (to) of portions of the water jacket () between intake ports () and the ignition plug mounting hole () and between exhaust ports () and the ignition plug mounting hole () are set to be lower than upper surfaces (to) of the remaining portions of the water jacket () around the ignition plug mounting hole () to increase the rigidity. Thereby, deformation of the cylinder head () due to cylinder internal pressure is limited, and the stress concentration around the ignition plug mounting hole () due to such deformation is reduced.

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Toyota, Japan

Tsutomu Wakiya