Mazda Motor Corporation

Haruyoshi Ishimi

Koji Asanomi

Tetsuji Yahiro

Masahiro Choushi

An improved, compact auxiliary mechanism driving device in a V-type, overhead-camshaft engine in which a driving section for engine auxiliary mechanism is mounted on a camshaft without increasing the overall size of the engine by utilizing a vacant or unused space(s) on the camshafts peculiar to such an overhead-camshaft engine. A pair of first and second cylinder banks are arranged in V-shape and have a first and a second cylinder head, respectively. The cylinders of the first bank are displaced from the cylinders of the second bank in the axial direction of the camshaft. A first camshaft having first valve-operating cams for the first cylinders is provided on the first cylinder head of the first cylinders. A second camshaft having second valve-operating cams for the second cylinders is provided on the second cylinder head of the second cylinders. The first and second camshafts are operatively connected at their one end with the associated end of the crankshaft for synchronized rotation therewith through a transmission mechanism. The first cams on the first camshaft are displaced from the second cams on the second camshaft in a manner such that the former are disposed axially more apart from the transmission mechanism than the latter. The engine auxiliary mechanism is driven by means of the first camshaft and has a drive section mounted on the first camshaft at a location between the transmission mechanism and the one of the first cams on the first camshaft nearest to the transmission mechanism.

Auxiliary mechanism driving device in a V-type engine

A V-type engine having a pair of cylinder banks set at an angle to each other is provided with a plurality of separate intake passages, each for one cylinder. The intake passages have respective proximate portions at which the intake passages to the cylinders in one cylinder bank and those to the cylinders in the other cylinder bank are in proximity or aligned with each other as viewed in the direction of the crankshaft. An exhaust recirculation passage for recirculating exhaust gas from the exhaust passage to the cylinders extends along the proximate portions in the direction of the crankshaft and is communicated with each intake passage by way of a communicating hole.

Exhaust gas recirculation system for a V-type engine

A V-type engine comprises a cylinder block forming first and second cylinder banks arranged in V-shape. Each cylinder bank is provided with a row of cylinders extending in the axial direction of the crankshaft between the front and rear ends of the engine. The cylinder row in the second cylinder bank starts from a location spaced apart from the front end of the engine and the cylinder row in the first cylinder bank starts from a location near the front end of the engine so that the cylinder row in the second cylinder bank is axially rearwardly displaced from that in the first cylinder bank. A water pump is mounted on the front end of the cylinder block substantially at the center between the first and second cylinder banks. A coolant inlet-passage to the water pump is provided in the part of the cylinder block between the foremost cylinder in the second bank and the front end of the cylinder block, which part is a dead space.

V-Type 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

Hiroshima, Japan

Haruyoshi Ishimi