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US 5,394,845 AGranted
Intake system for engine
AssigneeMazda Motor Corporation
InventorsYoshihisa Noh, Yoshihiko Imamura, Fumihiko Saito, Kazuhiko Hashimoto, Masanori Misumi
Life of this patent
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Abstract
An engine intake system includes a primary port for introducing intake gas throughout an entire engine operating condition. A secondary port is provided with a gate valve which is opened in a high engine load condition for introducing the intake gas. A ratio of a tumble flow to a swirl flow is gradually increased as the gate valve is operated from an entirely closed condition to a fully open condition. According to this invention, ignition and combustion characteristics can be improved.
Claims20
An engine intake system comprising:
- a primary port for introducing intake gas throughout an entire engine operating condition and having an axis, and
- a secondary port provided with a gate valve which is opened in a high engine load condition for introducing the intake gas and having an axis,
- both axes being inclined to one side with regard to a camshaft axis as seen along a cylinder bore axis of an engine,
- the axis of the primary port being inclined at an angle larger than an angle at which the axis of the secondary port is inclined with regard to the cylinder bore axis of the engine as seen along the camshaft axis,
- a ratio of a tumble flow to a swirl flow being gradually increased as the gate valve is operated from an entirely closed condition to a fully open condition.
2 more elements
An engine intake system comprising:
- a primary port for introducing intake gas throughout an entire engine operating condition, and
- a secondary port provided with a gate valve which is opened in a high engine load condition for introducing the intake gas,
- wherein both axes of the primary and secondary ports are inclined to one side with regard to a camshaft axis in a view along a cylinder bore axis of the engine,
- the secondary port being disposed in such a manner that the secondary port axis is substantially directed to an ignition plug disposed in a substantially central portion of a cylinder bore of the engine,
- a primary port curved portion is provided adjacent to a port opening located at a downstream end of the primary port and continued to a combustion chamber of the engine,
- a secondary port curved portion is provided adjacent to a port opening located at a downstream end of the secondary port and continued to the combustion chamber of the engine,
- a primary port straight portion is extended upstream from the primary port curved portion,
- a secondary port straight portion is extended upstream from the secondary port curved portion, and
- the primary port and secondary port straight portions are provided so that a distance between the primary port axis and secondary port axis is reduced to the downstream thereof in a view along the cylinder axis.
6 more elements
An engine intake system comprising:
- a primary port for introducing intake gas throughout an entire engine operating condition, and
- a secondary port provided with a gate valve which is opened in a high engine load condition for introducing the intake gas,
- wherein a primary port inclination angle .alpha. between an axis of the primary port straight portion and a plane perpendicular to a cylinder axis is provided at a small value compared with the secondary port in a view along a camshaft axis,
- the angle .alpha., a primary intake valve inclination angle .theta. between an axis of a primary intake valve and the cylinder axis, a first exhaust valve inclination angle .theta.' between an axis of a first exhaust valve facing the primary intake valve and the cylinder axis and a valve body angle .beta. between upper and lower surfaces of the valve body of the primary intake valve satisfying the following condition in a view along the cam shaft axis:
- .beta.>.theta. and .alpha.<.theta.'.
2 more elements
An engine intake system comprising:
- a primary port for introducing intake gas throughout an entire engine operating condition, and
- a secondary port provided with a gate valve which is opened in a high engine load condition for introducing the intake gas,
- wherein a primary port inclination angle .alpha. between an axis of the primary port straight portion and a plane perpendicular to a cylinder axis is provided at a small value compared with the secondary port in a view along a camshaft axis and the combustion chamber is of a pentroof configuration, the primary port inclination angle .alpha., the primary intake valve inclination angle .theta., a roof inclination angle .theta.", between a roof surface of the combustion chamber in the vicinity of an exhaust valve and a plane perpendicular to the cylinder axis and the valve body angle .beta. satisfying the following condition in a view along the camshaft axis:
- .beta.>.theta. and .alpha.<.theta.".
1 more element
A control method for controlling an engine intake system comprising the steps of:
- introducing intake gas through a primary port to form swirl flow in a combustion chamber of an engine in a low engine load condition,
- introducing the intakes gas through a secondary port by opening a gate valve disposed in the secondary port to form a tumble flow as the engine load is increased, axes of both the primary port and the secondary port being inclined to one side with regard to a camshaft axis as seen along a cylinder bore axis of the engine, the axis of the primary port being inclined at an angle larger than an angle at which the axis of the secondary port is inclined with respect to the cylinder bore axis of the engine as seen along the camshaft axis, and
- controlling opening of the gate valve in such a manner that a ratio of the tumble flow to the swirl flow is gradually increased as the gate valve is operated from an entirely closed condition to a fully open condition.
Dependencies are inferred from the claim text.