Abstract: An arrangement for supporting an electronic control unit (1) on an internal combustion engine. The electronic control unit is provided to bridge a part (7) of an engine main body assembly (6) and a part (9) of an air intake assembly (11). The part of the air intake assembly (11) is preferably an intake air pipe (9). The part of the engine main body assembly (6) is preferably a head cover (7). Therefore, the weight of the electronic control unit (1) is partly supported by the head cover (7) of which rigidity is high. The electronic control unit (1) is inclined towards the head cover (7) so that a larger ratio of the weight of the electronic control unit is supported by the head cover.

Abstract: A valve drive mechanism for a DOHC engine which leaves sufficient installation space for a functional part (16) to be located at a central portion of each of cylinder bores (15) even if each cylinder bore is relatively small. When viewed from the top, two intake valves (1) are linearly arranged in parallel to the longitudinal center line of the engine and two exhaust valves (2) are linearly arranged on the opposite side. The center line (8) of an intake camshaft (4) is offset from the mutual center line of the linearly arranged intake valves in a transverse direction of the engine to an outside direction of the associated cylinder bore such that the intake camshaft center line (8) is apart from the longitudinal center line of the engine and the exhaust camshaft center line (8) is offset in the opposite transverse direction from the mutual center line (6) of the linearly arranged exhaust valves (2), with the parallel relationship between the intake and exhaust camshafts being maintained.

Abstract: A resin-made belt pulley (p) including a rim (2) over which a belt is engaged and a web (3) molded together with the rim and mounted on a rotating shaft, (1) extending through a position radially inside of the pulley, characterized in that a mounting position (30) of the web (2) on the rotating shaft (1) is offset (12) from the center (8) of the rim (2) in an axial direction, and the web (3) includes a vertical web portion (7) extending from the mounting position (30) of the web in a radially outward direction of the rotating shaft (1) and inclined web portions (9) diagonally connecting the vertical web portion (7) to the center (8) of the rim in the axial direction. Since a belt tension acting on the rim (2) is born at the center position (8) of the rim (2), deformation of the rim (2) caused by the belt tension can be minimized even if the pulley (p) is fabricated from resin which is a material of low rigidity.

Abstract: A valve operating apparatus for DOHC engine allowing to improve the fuel consumption, in DOHC engines, is provided with by reducing the weight of the shaft system of valve operating mechanism and lowering the driving force for the dynamic valve and, at the same time, permitting to improve the durability and the silence of the transmission system and, moreover, assuring a good combustion even for engines having smaller bore diameter. A first and a second cam shafts for opening/closing the intake/exhaust valve are arranged side by side on a cylinder head, a first transmission means is disposed at a shaft end of the first cam shaft positioned at one side of the engine and, at the same time, shaft ends of the first and second cam shafts located at the other side of the engine are linked for the transmission of the driving power by a second transmission means.

Abstract: The present invention provides a direct injection type multicylinder engine capable of reducing the dimensions and number of parts thereof by forming so as to be used in common the cam brackets for retaining cam shafts, clamp members for fixing adjacent injectors, and fixing stud bolts. The cam brackets comprise singly formed parts, and retain the cam shafts rotatably on a cylinder head. The clamp members are adapted to fix adjacent injectors to the cylinder head at once. The cam brackets and clamp members are fixed to the cylinder head by inserting first common stud bolts through the central portions of the cam brackets and those of the cam brackets. The engine can be miniaturized by reducing the distance between the cam shafts, and the number of the parts required to retain the injectors and cam shafts is reduced.

Abstract: This injector mounting structure has attained the reduction of the length of a fuel pipe, a total height of an engine and a distance between cam shafts. A fuel supply boss extends from the relative injector diagonally at a predetermined angle, and passes a position close to the cam shafts and then a position between cams mounted on these cam shafts, so that it becomes possible to minimize the total height of an injector body, and reduce the length of the fuel pipe to be connected to a fuel supply boss. The fuel supply boss is provided with an escape portion for preventing the fuel supply boss and cam shafts from interfering with each other, whereby the fuel supply boss and cam shafts may be disposed closer to each other. The distance between the cam shafts becomes shorter, and the shafts of the suction and exhaust valves can be disposed closer to each other as they are kept parallel to each other, the performance of even a miniaturized engine being not deteriorated.