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US 4,785,776 AGranted
Diesel engine having shaped flame dispersing recess in piston crown
AssigneeNissan Motor Co., Ltd.
InventorsNaomi Tokura, Toshiaki Tanaka, Motohiro Shinzawa
Life of this patent
Estimating the term…
Abstract
A piston crown is formed with cavity a which includes a first flame deflecting member which divides the flame ejected from a transfer port interconnecting a swirl chamber with a main combustion chamber while the piston is relatively close to its TDC position and a second flame deflecting arrangement which divides the flame flow after the piston has descended by a given amount. The stage deflections of the flame promotes extensive dispersion thereof and the formation of a flame plume which engulfs a relatively large amount of the air in the combustion chamber and improves mixing of the burning gases and unburnt fuel with the air in the combustion chamber.
Claims21
In an internal combustion engine
- a piston reciprocatively disposed in a bore to define a variable volume combustion chamber;
- and
- a chamber into which fuel is supplied, said chamber being fluidly communicated with the combustion chamber by a transfer port;
- said piston comprising:
- a first flame deflecting surface defined in a cavity formed in the crown of said piston, said first flame deflecting surface being located in the path of a flame which is ejected from said transfer port while said piston is relatively close to a TDC position;
- a second flame deflecting surface, said second flame deflecting surface being defined in the cavity and comprises a portion of a peripheral wall defining said cavity, said second flame deflecting surface being positioned directly opposite said transfer port and located in the path of said flame after said piston has descended from said TDC position by a given amount, said first flame deflecting surface being arranged with respect to said second flame deflecting surface so that while said pistion is close to TDC said first flame deflecting surface is interposed between said transfer port and said second flame deflecting surface whereby only said first flame deflecting surface deflects the flame which issues from said transfer port until such time as the piston has descended by said given amount.
3 more elements
In an internal combustion engine:
- a piston reciprocatively disposed in a bore to define a variable volume combustion chamber;
- a chamber into which fuel is supplied, said chamber being fluidly communicated with the combustion chamber by a transfer port;
- a cavity formed in a crown of the piston, said cavity comprising:
- means defining a first flame deflecting surface, said first flame deflecting surface being located between the center of the piston and the location whereat said transfer port opens into said combustion chamber;
- and
- means defining a second flame deflecting surface comprising a portion of a peripheral wall defining said cavity, said second flame deflecting surface being positioned directly opposite said transfer port, said second flame deflecting surface being aligned with the location where said transfer port communicates with said combustion chamber and said first flame deflecting surface and more distal from said location than said first flame deflecting surface, said first flame deflecting surface being interposed between said transfer port and said second flame deflecting surface when said piston is close to TDC, said second flame deflecting surface being arranged to be exposed to a flame which ejects from said transfer port only after said piston has descended from TDC by a predetermined amount.
3 more elements
In an internal combustion engine
- a piston reciprocatively disposed in a bore to define a variable volume combustion chamber;
- a chamber into which fuel is supplied, said chamber being fluidly communicated with the combustion chamber by a transfer port;
- a cavity formed in the crown of the piston, said cavity being defined between first and second shaped wall portions comprising:
- a first flame deflecting surface, said first flame deflecting surface being located between the center of the piston and the location whereat said transfer port opens into said combustion chamber;
- first and second flame guides which form part of said first shaped wall portion, said flame guides being oriented inwardly to deflect the flame which has been deflected by said first flame deflecting surface back in toward the the center of the piston crown;
- and
- a second flame deflecting surface, said second flame deflecting surface being defined by part of said second wall portion and aligned by (a) the location where said transport communicates with said combustion chamber and (b) said first flame deflecting surface.
4 more elements
A method of operating an internal combustion engine comprising the steps of:
- forming a combustible air fuel mixture charge in a pre-chamber which is fluidly communicated with a combustion chamber via a transfer port;
- inducing the charge to combust;
- directing a flame through said transfer port into said combustion chamber into a cavity formed in the crown of the piston;
- deflecting the flame using only a first deflecting surface while the piston is relatively close to a TDC position;
- and
- deflecting the flame using a second deflecting surface when the piston has descended from said TDC position by a given amount wherein said first deflecting surface is no longer interposed between said transfer port and said second deflecting surface.
3 more elements
In an internal combustion engine
- a piston reciprocatively disposed in a bore to define a variable volume combustion chamber;
- and
- a chamber into which fuel is supplied, said chamber being fluidly communicated with the combustion chamber by a transfer port;
- said piston comprising:
- a first flame deflecting surface defined in a cavity formed in the crown of said piston, said first flame deflecting surface being located in the path of a flame which is ejected from said transfer port while said piston is relatively close to a TDC position;
- a second flame deflecting surface, said second flame deflecting surface being defined in the cavity and comprises a portion of a peripheral wall defining said cavity, said second flame deflecting surface being positioned directly opposite said transfer port and located in the path of said flame after said piston has descended from said TDC position by a given amount;
- a second shaped cavity, said second shaped cavity being formed in the crown of said piston and located essentially diametrically with respect to the location whereat said transfer port opens into said combustion chamber and so that said first and second flame deflecting portions are located between it and said location.
4 more elements
In an internal combustion engine
- a piston reciprocatively disposed in a bore to define a variable volume combustion chamber;
- and
- a chamber into which fuel is supplied, said chamber being fluidly communicated with the combustion chamber by a transfer port;
- said piston comprising:
- a first flame deflecting surface defined in a cavity formed in the crown of said piston, said first flame deflecting surface being located in the path of a flame which is ejected from said transfer port while said piston is relatively close to a TDC position;
- a second flame deflecting surface, said second flame deflecting surface being defined in the cavity and comprises a portion of a peripheral wall defining said cavity, said second flame deflecting surface being positioned directly opposite said transfer port and located in the path of said flame after said piston has descended from said TDC position by a given amount;
- wherein said first deflecting surface has an essentially V shape having a first predetermined included angle and wherein said second deflecting surface has an essentially V shape having a second predetermined included angle, said second predetermined angle being smaller than said first predetermined angle.
4 more elements
In an internal combustion engine
- a piston reciprocatively disposed in a bore to define a variable volume combustion chamber;
- and
- a chamber into which fuel is supplied, said chamber being fluidly communicated with the combustion chamber by a transfer port;
- said piston comprising:
- a first flame deflecting surface defined in a cavity formed in the crown of said piston, said first flame deflecting surface being located in the path of a flame which is ejected from said transfer port while said piston is relatively close to a TDC position;
- a second flame deflecting surface, said second flame deflecting surface being defined in the cavity and comprises a portion of a peripheral wall defining said cavity, said second flame deflecting surface being positioned directly opposite said transfer port and located in the path of said flame after said piston has descended from said TDC position by a given amount;
- wherein said cavity further includes:
- a first essentially crescent shaped recess portion;
- a trench which blends with said first recess portion, said trench having an end located proximate the perimeter of said piston and below the location said transfer port opens into said combustion chamber;
- second and third essentially circular recess portions which blend with each other and said first recess portion, said first and second recess portions respectively extending to the edge of the piston crown.
7 more elements
Dependencies are inferred from the claim text.