Internal-combustion engines – Precombustion and main combustion chambers in series – Having combustible mixture forming means
Patent
1999-06-14
2000-11-28
Argenbright, Tony M.
Internal-combustion engines
Precombustion and main combustion chambers in series
Having combustible mixture forming means
1231936, 123279, F02B 2306, F02F 326
Patent
active
061521019
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an internal combustion (i.c.) engine, particularly a compression ignition engine, having a re-entrant type combustion bowl.
2. Description of the Related Art
In view of the increasing environmental and legislative pressures world-wide to improve i.c. engine exhaust emissions, engine manufacturers are now focusing their attention on the development of new engines to achieve substantial reductions in emissions without compromising combustion efficiency or specific fuel consumption. An important requirement for clean combustion in an i.c. engine is the enhancement of gas velocities within the engine cylinder. Swirl and squish influenced by combustion chamber shape play a significant role in satisfying this requirement around top-dead-centre (TDC), particularly in diesel fuelled engines. In general, comustion chamber shape is a dominant factor governing the structure of turbulence around TDC. In-cylinder turbulence enhancement in diesel fuelled engines using unique combustion chamber shapes can be highly beneficial in terms of improving air/fuel mixing and combustion processes, and is an important goal to achieve.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a piston for an internal combustion engine, particularly a compression ignition engine, which has the capability to produce high gas velocities within a combustion chamber over a critical period of engine cycle around TDC, particularly during the early stages of the power stroke.
According to a first aspect of the present invention, there is provided a piston for an internal combustion engine having a combustion bowl formed contiguous to a face of a crown of the piston, said combustion bowl having wall means defining a first volume and a second volume, said second volume being in communication with said first volume and being located generally axially to the piston below the first volume, wherein a smallest diameter of a throat portion connecting said first and second volumes is smaller than the greatest diameter of the first volume and is smaller than the greatest diameter of the second volume and the greatest diameter of the first volume is larger than the diameter of a mouth of the combustion bowl, and a portion of the wall means defining the first volume adjacent to the throat portion is at least parallel with or angled upwardly towards the face of the piston crown when viewed through the combustion bowl mouth.
The greatest diameter of the second volume may also be larger than the diameter of the combustion bowl mouth.
Alternatively, the greatest diameter of the second volume may be smaller than the diameter of the combustion bowl mouth.
The greatest diameter of the second volume may be equal to the greatest diameter of the first volume.
Alternatively, the greatest diameter of the second volume may be smaller than the greatest diameter of the first volume.
Alternatively also, the greatest diameter of the second volume may be larger than the greatest diameter of the first volume.
The axial depth of the second volume may be equal to the axial depth of the first volume.
Alternatively, the axial depth of the second volume may be smaller than the axial depth of the first volume.
Alternatively also, the axial depth of the second volume may be larger than the axial depth of the first volume.
The first and second volumes may be arranged to be co-axial.
Alternatively, the second volume may be radially offset with respect to the first volume.
At least the first volume may be arranged to be co-axial with the piston.
The first and second volumes may each be rotationally symmetrical.
The ratio of the diameter of the combustion bowl mouth to the diameter of the piston crown may be in the range of 0.15 to 0.85, but is preferably in the range of 0.3 to 0.6
The ratio of the smallest diameter of the throat portion to the greatest diameter of the second volume may be in the range of 0.4 to 0.9, but is preferably in the range of 0.5 to 0.9
REFERENCES:
patent: 4207843 (1980-06-01), List et al.
Argenbright Tony M.
Hickman Alan J.
Perkins Engines Company Limited
LandOfFree
Piston for an internal combustion engine having a re-entrant typ does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Piston for an internal combustion engine having a re-entrant typ, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Piston for an internal combustion engine having a re-entrant typ will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1714560