Nissan Motor Company Limited

Junichi Yokoyama

Ken Nakamura

Tomonori Urushihara

Yutaka Matayoshi

Teruyuki Itoh

Atsushi Yonezawa

Shigeru Kamegaya

Shigeo Muranaka

Giichi Shioyama

Mitsumasa Inoue

Tadashi Nagai

Hiromichi Ofuji

Eiichi Ohnishi

Hiroyuki Fujii

Kouzaburou Ohkawa

An exhaust system for internal combustion engines includes at least two exhaust passages, each passage communicated with at least one branch exhaust passage of an exhaust manifold communicating exhaust ports of a multiple-cylinder engine, and a confluent exhaust passage disposed downstream of said at least two exhaust passages, said confluent exhaust passage including a confluent point for converging downstream ends of said at least two exhaust passages. The exhaust system also includes a communication passage substantially parallel with the at least two exhaust passages and a valve disposed in the communication passage, for allowing a portion of exhaust gas flow to bypass said confluent point only when the engine is within a predetermined high engine revolution range.

Exhaust system for internal combustion engines

To smoothly introduce intake air or mixture through at least one intake valve and exhaust combustion gas through at least exhaust valve, an intake side conical wall surface is formed in an inner wall of the cylinder head in smooth continuous connection with a conical surface formed at an end of the intake valve seat, and an exhaust side conical wall surface is also formed in the inner wall of the cylinder head in smooth continuous connection with a conical surface formed at an end surface of the exhaust valve seat. It is preferable not to allow liquid fuel introduced through the intake to flow directly toward an ignition plug provided at the center of the cylinder, but to allow the introduced liquid fuel to flow directly toward the exhaust port along a flat surface, recess, groove, guide surface, etc. formed around the ignition plug for prevention of misfiring. Further, it is preferable to form a recess on a top surface of the piston, project the ignition plug from inner surface of the cylinder head, incline ignition plug toward the exhaust port, obstruct liquid introduced through the intake valve by a boundary projection formed between the intake and exhaust side conical wall surfaces, etc.

Combustion chamber for internal combustion engine

In order to prevent the electrodes of the spark plug from becoming wetted with droplets of liquid fuel during low temperature and/or idling operation of the engine in a manner which deteriorates engine stability, the branches of a bifurcate intake passage which cooperates with a dual inlet valve arrangement are arranged to guide the unvaporized liquid fuel into the combustion chamber in a manner which obivates contact with the plug. In some embodiments a passage which is adapted to produce a swirl in the combustion chamber is arranged so that the fuel which passes therethrough (usually in the form of a film on the walls of branches) and which has a relatively large inertia as compared with the gaseous charge, enters the combustion chamber with a velocity which carries it along a flight path non-intersective with the plug electrodes. In another arrangement, the swirl generating passage is arranged to branch off from the side of the other one which is essentially coaxially aligned with the passage of the induction manifold. With this arrangement most of the liquid fuel tends to pass into the essentially coaxially aligned one under the influence of its own inertia and thus reduces the amount of liquid fuel entering the swirl generating one.

Induction port arrangement for internal combustion engine having

In a variable venturi carburetor in which the metering jet portion of fuel changes automatically according to the amount of intake air required to keep the mixture at a constant air-to-fuel ratio at all times, two series-arranged nozzles and an auxiliary fuel passage communicating with the downstream side of the venturi and with the space formed between the two nozzles additionally formed at the fixed venturi portion in such a way that the auxiliary fuel passage can be opened or closed according to engine operating conditions. Therefore, when the auxiliary fuel passage is opened, since fuel is introduced into the venturi through only a single nozzle, a rich mixture is obtained; when the auxiliary fuel passage is closed, since fuel is introduced through two nozzles, a lean mixture is obtained.

Variable venturi carburetor

A cooling system for a liquid cooled automotive internal combustion engine comprises a first device responsive to the temperature of engine coolant flowing through a first section of a coolant passage leading to a radiator. Additionally, a second device is provided to be operative in response to the first device to control the flow of the coolant flowing through a second section of the coolant passage which second section is located downstream of the first section and upstream of a coolant pump. The second device is constructed and arranged to block the coolant passage second section at one of a low engine load operating range and a no engine load operating range when the coolant temperature is over a first predetermined level and not higher than a second predetermined level which is higher than the first predetermined level, while to allow the coolant flow through the coolant passage second section at all engine operating ranges when the coolant temperature is over the second predetermined level. Accordingly, fuel economy and hydrocarbon exhaust emission are effectively improved.

Cooling system for automotive internal combustion engine

An intake system of an internal combustion engine including a power cylinder having an intake valve and a fuel injection nozzle, comprising: a throttle chamber upstream open to the atmosphere; primary and secondary throttle valves provided in parallel with each other in the throttle chamber; primary and secondary air passageways leading from the throttle chamber past the primary and secondary throttle valves, respectively, and conjoined together upstream of the intake valve, the secondary passageway being larger in cross sectional area than the primary air passageway and having a reservoir chamber portion larger in cross sectional area than the remaining portion of the secondary passageway; and air heating means provided in the primary air intake pipe and operative to preheat the air to be passed through the primary air intake pipe.

Intake system of internal combustion engine

A cooling device for an internal combustion engine includes a communicating passage for communicating the inlet and outlet of a water pump, a cooling water temperature detecting means for detecting the temperature of cooling water for the engine and a valve controlled by the cooling water temperature detecting means for opening the communicating passage when the cooling water temperature is lower than a predetermined value and closing the passage when the temperature is higher than the value, so that when the engine is at a lower temperature the cooling water is not circulated through a cylinder block and a cylinder head of the engine, thereby rapidly raising the temperature of the engine to remarkably improve the exhaust gas characteristics and running performance and reduce the fuel consumption.

Cooling system for internal combustion engine

A device for controlling an acceleration pump for a carburetor includes a positioning member, a stopper and an actuating means. The positioning member is preferably formed integrally with a piston slidably set in the acceleration pump. The stopper is arranged to move in a direction perpendicular to a sliding direction of the piston. According to the positions of the stopper, the positioning member engages the stopper at a plurality of predetermined positions so that the stroke of the piston may change. The actuating means may be bellows or others. The bellows contains therein an air pressure equal to the standard air pressure at a low place whereby the bellows can expand at a high place due to the air pressure difference. In addition, the actuating means can be controlled in response to the ambient temperature.

Control device for acceleration pump

In an air-fuel mixture supply device for an internal combustion engine, a butterfly-type throttle valve is disclosed whose upstream face is formed with a raised portion extending around the major of its periphery, but which is broken at least at the middle of the downstream part of the periphery of this upstream face. Thereby distribution of the air-fuel mixture is improved between the cylinders of a multi-cylinder engine.

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Ebina, Japan

Junichi Yokoyama