Mazda Motor Corporation

Tetsuji Yahiro

Haruyoshi Ishimi

Masahiro Choushi

Makoto Araki

Katsunori Morimune

This invention relates to an engine suction apparatus in which a tuning frequency of pressure-vibration characteristics of a suction path on the upstream side of a throttle body coincides with a frequency of a pressure vibration applied from a suction port to the suction path at an idling engine speed. The suction apparatus includes an idling path, branching from the suction path on the upstream side of the throttle body, for supplying intake air in an idling state, and a resonance silencer which resonates at the tuning frequency to reduce noise is connected to the idling path.

Suction apparatus for engine

A V-type overhead-camshaft engine comprises first and second banks arranged in V-shape, each bank having a row of a plurality of cylinders extending axially between front and rear ends thereof. The row of the cylinders in the first bank starts from a location spaced apart from the front end of the engine, and terminates at a location near the rear end of the same. The row of the cylinders in the second bank starts from a location near the front end of the engine and terminates at a location spaced apart from the rear end of the same. Each bank is provided with a cylinder head assembly which generally comprises a cylinder head and a head cover, and supports a camshaft. The cylinder head assembly of the first bank is provided with an opening at a location corresponding to the part of the bank between the front end of the engine and the foremost cylinder in the first bank, while the cylinder head assembly of the second bank is provided with an opening at a location corresponding to the part of the second bank between the rear end of the engine and the rearmost cylinder in the second bank. The openings in the cylinder head assemblies of the first and second banks are identical to each other and are located symmetrically with respect to the center of the engine. One of the openings is used as an oil filler section, and the other opening is used as an engine auxiliary mechanism mounting section.

V-Type overhead-camshaft engine

A V-type engine comprises a cylinder block, and first and second cylinder heads mounted on the cylinder block to form first and second cylinder banks arranged in V-shape, the front end face of the cylinder block at the first cylinder bank being substantially flush with the front end face of the cylinder block at the second cylinder head, the rear end face of the cylinder block at the first cylinder block being substantially flush with the rear end face of the cylinder block at the second cylinder block, and the first and second cylinder heads being shaped to conform to the shape of the cylinder block. Each cylinder bank is provided with a row of cylinders extending axially between the front and rear end surfaces thereof. The row of the cylinders in the first cylinder bank starts from a location spaced apart from the front end face and terminates at a location near the rear end face, while the row of the cylinders in the second cylinder bank starts from a location near the front end face and terminates at a location spaced apart from the rear end face so that the row of the cylinders in the first cylinder bank is axially rearwardly displaced from that in the second cylinder bank. An oil-return passage to the crankcase extending through the cylinder block and the cylinder head to communicate the crankcase and the upper surface of the cylinder head is formed at a location between the foremost cylinder in the first cylinder bank and the front end face of the first cylinder bank and/or at a location between the rearmost cylinder in the second bank and the rear end face of the second cylinder bank.

Growing community of inventors

Higashihiroshima, Japan

Tetsuji Yahiro