COMPRESSION-IGNITION INTERNAL COMBUSTION ENGINE
FIG9 is a transverse cross-sectional view obtained by cutting a passage wall portion along an A-A line in FIG8
The second layer 88b is located radially outward of the first layer 88a. According to the example shown in FIG9, the second layer 88b is formed so as to cover the first layer 88a that protrudes from the base surface 84a1 of the combustion chamber ceiling 84a. In addition, according to this example, the second layer 88b is formed so as to also cover an end surface 88a1 of the first layer 88a located on the inlet side of the flow guide passage 86.
transverse cross-sectional view
80
internal combustion engine
22
nozzle hole nozzle holes
86
flow guide passage
84
cylinder head
20
fuel injection nozzle
88
passage wall portion
82
combustion chamber
['1. A compression-ignition internal combustion engine (10; 80; 90), comprising: a fuel injection nozzle (20) including a tip end portion (20a) exposed in a combustion chamber (12; 82; 92) and a nozzle hole (22) formed at the tip end portion (20a); and a passage forming member (30; 40; 50; 60; 70; 84; 98) forming a flow guide passage (32; 86; 96) through which fuel injected from the nozzle hole (22) passes, wherein the passage forming member (30; 40; 50; 60; 70; 84; 98) includes a passage wall portion (36; 42; 52; 62; 72; 88; 100) located radially outward of the flow guide passage (32; 86; 96), wherein the passage wall portion (36; 42; 52; 62; 72; 88; 100) includes a first layer (36a; 42a; 52a; 62a; 72a; 88a; 100a) that is a base portion connected to a cylinder head (18; 84; 94), and a second layer (36b; 42b; 52b; 62b; 72b; 88b; 100b) located radially outward or radially inward of the first layer (36a; 42a; 52a; 62a; 72a; 88a; 100a), wherein a toughness of the first layer (36a; 42a; 52a; 62a; 72a; 88a; 100a) is higher than a toughness of the second layer (36b; 42b; 52b; 62b; 72b; 88b; 100b), and wherein a thermal conductivity of the second layer (36b; 42b; 52b; 62b; 72b; 88b; 100b) is lower than a thermal conductivity of the first layer (36a; 42a; 52a; 62a; 72a; 88a; 100a).']