DIRECT FUEL INJECTION DIESEL ENGINE

• US 20100006061A1
• Filed: 04/11/2007
• Published: 01/14/2010
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Uchimoto, Tatsuya, Sasaki, Nobuhiko, Ikeya, Kenichiro, Sono, Hiroshi, Tajima, Yutaka, Shibata, Mitsuhiro, Yamaya, Yukihisa
• Granted Patent: US 8,056,532 B2
• Time in Patent Office: Days
• US Class Current: 123/307
• CPC Class Codes: F02B 2275/14 Direct injection into combustion chamber
• CPC Class Codes: F02B 23/0621 Squish flow
• CPC Class Codes: F02B 23/0657 the spray interacting with one or more glow plugs
• CPC Class Codes: F02B 23/0669 having multiple fuel spray jets per injector nozzle
• CPC Class Codes: F02B 23/0696 W-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder wall
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02F 1/242 Arrangement of spark plugs or injectors
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

In a direct fuel injection diesel engine having a piston with a pentroof-shaped top face, with regard to a pentroof-shaped piston (13) with a cavity (25) recessed in a central part of the top face, a radial width S of a squish area (26) formed between an outer peripheral part of the top face and a lower face of a cylinder head (14) changes in the circumferential direction of the piston (13). By setting a squish clearance H large for a portion where the radial width S of the squish area (26) is large and setting the squish clearance H small for a portion where the radial width S of the squish area (26) is small, more specifically, by setting S/H so that it is constant in the circumferential direction, it is possible to make the strength of the squish flow uniform in the circumferential direction of the piston, thus promoting the mixing of air and fuel and reducing harmful exhaust components.

Claims

1. A direct fuel injection diesel engine comprising a piston (13) for which the height of a top face changes in the circumferential direction, and a fuel injector (23) for injecting fuel into a cavity (25) recessed in a central part of the piston (13), a ratio D/B of a cavity entrance diameter D to a cylinder bore diameter B in a plane perpendicular to a piston central axis (Lp) changing in the circumferential direction,

characterized in that a squish clearance (H) formed between the top face of the piston (13) radially outside the cavity (25) and a lower face of a cylinder head (16) increases in response to a decrease in the ratio D/B and decreases in response to an increase in the ratio D/B.

2. A direct fuel injection diesel engine comprising a piston (13) for which the height of a top face changes in the circumferential direction, and a fuel injector (23) for injecting fuel into a cavity (25) recessed in a central part of the piston (13), a ratio D/B of a cavity entrance diameter D to a cylinder bore diameter B in a plane perpendicular to a piston central axis (Lp) changing in the circumferential direction,

characterized in that a cutout (13e) is formed in at least one of a portion of the top face of the piston (13) where the ratio D/B is a minimum and a portion of a cylinder head (16) that faces said portion.