Combustion chamber for diesel engines
AssigneesMitsubishi Motors Corporation, NGK Insulators, Ltd.
InventorsHiroshi Oikawa, Naohisa Nakashima, Minoru Matsui, Tadao Ozawa
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Abstract
The disclosure relates to a novel arrangement of a combustion chamber for diesel engines, which is defined by an inner wall including a fuel-impinging area formed of a metallic material, and a remaining area which at least partly is formed of a ceramic material or a like heat-resisting material. The arrangement serves to achieve an effective exhaust gas clarification, including the minimization of NOx emission, and to realize increased power output and reduced fuel consumption of the engine.
Claims19
A combustion chamber for a diesel engine, comprising:
- an inner wall comprising
- (a) a fuel impinging area upon which fuel is directly injected, said fuel impinging area comprising a top surface of a piston head and an inner wall of a cavity formed in said piston head, and consisting essentially of a thermally conductive metallic member, and
- (b) a remaining area which is shielded from direct injection of fuel and which at least partially consists of a heat-resisting material, said remaining area comprising a first layer of heat-resisting material arranged beneath a lower surface of a cylinder head;
- and
- a sintered ceramic body consisting of partially stabilized zirconia arranged between said lower surface of said cylinder head and said first layer of heat-resisting material;
- wherein that portion of said combustion chamber inner wall which is formed of said heat-resisting material has a surface area ratio of at least 40% with respect to a total surface area of said combustion chamber inner wall except a surface area of said cavity.
A combustion chamber for a diesel engine, comprising:
- an inner wall comprising:
- (a) a fuel impinging area upon which fuel is directly injected, said fuel impinging area comprising a top surface of a piston head and an inner wall of a cavity formed in said piston head, and consisting essentially of a thermally conductive metallic member, and
- (b) a remaining area which is shielded from direct injection of fuel and which at least partially consists of a heat-resisting material, said remaining area comprising a first layer of heat-resisting material arranged beneath a lower surface of a cylinder head and arranged on at least a portion of an outer peripheral surface of a piston top land;
- and
- a sintered ceramic body consisting of partially stabilized zirconia arranged between said lower surface of said cylinder head and said first layer of heat-resisting material;
- wherein that portion of said combustion chamber inner wall which is formed of said heat-resisting material has a surface area ratio of at least 40% with respect to a total surface area of said combustion chamber inner wall except a surface area of said cavity.
Dependencies are inferred from the claim text.