Mazda Motor Corporation

Kazuaki Nishimura

Hiroichi Takubo

Yasushi Niwa

Hiroaki Deguchi

Satoshi Nishizaka

Toshinobu Itoh

Takafumi Teramoto

Fuminori Ishimura

Sachiko Nakagawa

Hiroshi Kagaya

Kuniaki Kakui, Deceased

A first turbocharger comprises a first center housing and a first return passage. A second turbocharger comprises a second center housing and a second return passage. The first return passage joins the second return passage at a junction. The length of the second return passage from the second center housing to the junction is longer than that of the first return passage from the first center housing to the junction. A bellows-shaped vibration absorption portion is provided at the second return passage. The first return passage comprises a first upstream return passage and a first downstream return passage, and the first upstream and downstream return passages are connected to each other via the flexible hose.

Lubrication device of turbocharger of engine for vehicle

There are provided first and second water supply passages to supply cooling water from an engine to first and second center housings of first and second turbochargers, and first and second return passages to return the cooling water from the first and second turbochargers to the engine. A cooling-water connection portion of the first water supply is located above the level of a cooling-water connection portion of the second water supply passage. A vapor releasing passage is provided between the second turbocharger and an upper tank provided on the outside of an engine body at a position located above the connection portion of the second return passage of the second turbocharger. Accordingly, the function of vapor releasing from the first and second turbochargers can be improved, thereby increasing the layout flexibility around the engine.

Cooling device of turbocharger of engine for vehicle

A double overhead camshaft engine has a pair of camshafts, interconnected by gearing, which are disposed in juxtaposition over a cylinder head and supported by bearings. Either one of the camshafts is coupled to a crankshaft by a timing belt. A sealing member is disposed between the engine and a front cover so as to sealingly enclose and hide the timing belt. The sealing member, in the form of a rib forming a closed loop, is divided into a plurality of rib segments, at least one of which is formed integrally with the bearing member.

Double overhead camshaft bearing structure

An arrangement for supporting a crankshaft in a multicylinder engien comprises a plurality of bulkheads provided in a cylinder block of the engine to be arranged at predetermined intervals along an axis of the crankshaft disposed in the cylinder block, a plurality of bearing caps each coupled with a lower end of one of the bulkheads by a cap bolt screwed into the bulkhead through a part of the bearing cap relatively close to the bulkhead so as to constitute a bearing portion for supporting the crankshaft in conjunction with the bulkhead, a beam structure extending along the axis of the crankshaft to interconnect therethrough adjacent two of the bearing caps, and a reinforcing structure coupled with the beam structure with a plurality of clamped spots generally arranged in the direction along which the crankshaft extends and also coupled with each of side skirt portions of the cylinder block with a plurality of clamped spots generally arranged in the direction along which the crankshaft extends.

Arrangements for supporting crankshafts in multicylinder engines

An engine cylinder block structure includes: a cylinder block integrally formed to include skirts projecting downwardly from both sides of the lower surface of the cylinder block; an oil pan attached to lower surfaces of both skirts of the cylinder block, the oil pan having a deep first portion on a front side and a shallow second portion on a rear side, the first and second portions being connected to each other; flanges integrally formed on lower ends of the skirts for having the oil pan attached thereto; and reinforcing mechanism for reinforcing the strength of both skirts. The reinforcing mechanism includes: a plate-shaped reinforcing member for reinforcing the strength of both skirts, the plate-shaped reinforcing member spanning and interconnecting portions corresponding to a range extending between the first portion of the oil pan and a portion excluding the rear end of the second portion of the oil pan; and stiffening mechanism for providing portions of the flanges corresponding to the second portion of the oil pan with a rigidity higher than that of portions of the flanges corresponding to the first portion of the oil pan.

Engine cylinder block reinforcing structure

In an engine cooling structure in which a water pump for causing a cooling water or coolant to flow in a watercool engine is located at or near one end portion of a cylinder block in the direction of the cylinder alignment, coolant passages include a main coolant passage disposed in a cylinder head and the cylinder block, a radiator circulating passage leading the cooling water from the water pump through an engine body to a radiator core, a by-pass passage by-passing the radiator core, and a heater circulating passage leading the cooling water from the engine body to an air-conditioning heater. The radiator circulating passage and the by-pass passage are arranged so as to switch by a thermostat valve. The by-pass passage and/or the heater circulating passage are or is constructed so as to have a coolant return passage disposed in the cylinder block extending in the direction of the cylinder alignment.

Engine cooling structure

A cylinder block construction of an engine having a pair of balancer shafts provided at its opposite sides, in which the cylinder block is formed with a pair of bearing boss portions for supporting the balancer shafts, respectively. The cylinder block construction includes a pair of mounting portions for securing a pair of engine mounts to the cylinder block, respectively, which are, respectively, provided, in the vicinity of the bearing boss portions, at opposite side walls of the cylinder block so as to be integrally formed with the bearing boss portions.

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Hiroshima, Japan

Kazuaki Nishimura