Flow duct for an internal combustion engine
First Claim
1. A flow duct, particularly an intake duct, in an intake system and a cylinder head of an internal-combustion engine, in which a gas flow is controlled by means of a valve which comprises a valve disk interacting with a valve seat and a valve stem having a longitudinal axis which is connected with the valve seat and, in an axially movable manner, is disposed in a valve stem guide, the valve stem being arranged adjacent to the valve seat ring in the intake duct in such a manner that it is subjected to the gas flow, wherein the intake duct is divided into a first, contracting duct section in the intake system and a second, widening duct section in the cylinder head, said intake duct extending in a linear non-offset manner from a plane including the valve stem axis and being provided with a defined flow profile which, until it reaches a cross-sectional transition area situated relatively close and upstream of the valve stem, has a uniform cross-sectional contraction and, downstream of said contraction, has a uniform cross-sectional widening.
1 Assignment
0 Petitions
Accused Products
Abstract
A flow duct, particularly an intake duct in an intake system and a cylinder head of an internal-combustion engine has a defined flow profile by means of which the flow rate of the gas flow is accelerated continuously, specifically until it reaches a cross-sectional transition area of the intake duct which--viewed in the flow direction--is situated upstream of a valve stem. After that, the flow rate of the gas flow is reduced whereby a lower approach flow speed of the valve is achieved. This causes an optimized volumetric efficiency which has a favorable effect on the power and the consumption of the internal-combustion engine.
21 Citations
9 Claims
- 1. A flow duct, particularly an intake duct, in an intake system and a cylinder head of an internal-combustion engine, in which a gas flow is controlled by means of a valve which comprises a valve disk interacting with a valve seat and a valve stem having a longitudinal axis which is connected with the valve seat and, in an axially movable manner, is disposed in a valve stem guide, the valve stem being arranged adjacent to the valve seat ring in the intake duct in such a manner that it is subjected to the gas flow, wherein the intake duct is divided into a first, contracting duct section in the intake system and a second, widening duct section in the cylinder head, said intake duct extending in a linear non-offset manner from a plane including the valve stem axis and being provided with a defined flow profile which, until it reaches a cross-sectional transition area situated relatively close and upstream of the valve stem, has a uniform cross-sectional contraction and, downstream of said contraction, has a uniform cross-sectional widening.
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8. A process for influencing the flow rate of the gas flow in a flow duct particularly an intake duct, in an intake system and a cylinder head of an internal-combustion engine, in which a gas flow is controlled by means of a valve which comprises a valve disk interacting with a valve seat and a valve stem having a longitudinal axis which is connected with the valve seat and, in an axially movable manner, is disposed in a valve stem guide, the valve stem being arranged adjacent to a valve seat ring in the intake duct in such a manner that it is subjected to the gas flow, wherein the intake duct is divided into a first, contracting duct section in the intake system and a second, widening duct section in the cylinder head disposed downstream of the first duct section, said intake duct extending in a linear non-offset manner from a plane including the valve stem axis and being provided with a defined flow profile which, until it reaches a cross-sectional transition area situated relatively close and upstream of the valve stem, has a uniform cross-sectional contraction and, downstream of the contraction, has a uniform cross-sectional widening, and wherein the flow rate of the gas flow in the first duct section and in the second duct section is increased continuously until reaching the cross-sectional transition area and after that is continuously reduced.
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9. A process for manufacturing a flow duct, particularly an intake duct, in an intake system and a cylinder head of an internal-combustion engine, in which a gas flow is controlled by means of a valve which comprises a valve disk interacting with a valve seat and a valve stem having a longitudinal axis which is connected with the valve seat and, in an axially movable manner, is disposed in a valve stem guide, the valve stem being arranged adjacent to a valve seat ring in the intake duct in such a manner that it is subjected to the gas flow, wherein the intake duct is divided into a first, contracting duct section in the intake system and a second, widening duct section in the cylinder head disposed downstream of the first duct section, said intake duct extending in a linear non-offset manner from a plane including the valve stem and being provided with a defined flow profile which, until it reaches a cross-sectional transition area situated relatively close and upstream of the valve stem, has a uniform cross-sectional contraction and, downstream of said contraction, has a uniform cross-sectional widening.
Specification