Abstract: A direct injection diesel engine includes a piston having a reentrant cavity and a multi-hole fuel injection nozzle disposed on a center line of the cavity. The cavity is formed by a lip portion defining a smallest diameter at a position below a piston crown surface and a raised portion formed at a center of the bottom and shaped like a frustum of a cone. A conical surface of the raised portion is formed to have an angle pointing to a spray point of the fuel injection nozzle at a piston top dead center position. The height position of a top surface is substantially equal to the height position of the lip portion. This structure is to promote the oxidation of soot by utilizing the air in the central part of the cavity.

Abstract: A fuel injection nozzle disposed in a center of a reentrant cavity combustion chamber has first and second nozzle hole groups whose inclination angles with respect to a cylinder center axis line are different. A nozzle hole diameter of the second nozzle hole group is larger than that of the first one. First and second nozzle holes are alternately arranged in a circumferential direction. A glow plug projects, in a height direction of the cylinder, up to a height of a spray center axis line (F2) of the second nozzle hole directed at a lower side. Therefore the glow plug can contact fuel masses formed by sprays from both the first and second nozzle holes. The glow plug is positioned between spray center axis lines (F1, F2) in the circumferential direction, and positioned at a swirl downstream side of spray center axis line (F2).

Abstract: A piston of a direct injection type diesel engine has a re-entrant type cavity, and a fuel injection nozzle with multiple nozzle holes is arranged on the center line thereof. The cavity has a lip portion, which is the portion thereof having the smallest diameter, positioned below a piston crown surface and a pocket portion formed above the lip portion. The pocket portion is positioned at a height to which a pilot injection injected prior to the top dead center under engine idling is directed, and the position of a wall surface is so set that a leading part of the injection spray does not collide strongly therewith. The fuel from the pilot injection temporarily stays in the pocket portion and moves into the cavity by means of a subsequent squish flow. Accordingly, an increase in unburned hydrocarbons is suppressed.

Abstract: A direct injection diesel engine includes a piston having a reentrant cavity and a multi-hole fuel injection nozzle disposed on a center line of the cavity. The cavity is formed by a lip portion defining a smallest diameter at a position below a piston crown surface and a raised portion formed at a center of the bottom and shaped like a frustum of a cone. A conical surface of the raised portion is formed to have an angle pointing to a spray point of the fuel injection nozzle at a piston top dead center position. The height position of a top surface is substantially equal to the height position of the lip portion. This structure is to promote the oxidation of soot by utilizing the air in the central part of the cavity.

Abstract: Fuel injection nozzle (6) disposed in a center of reentrant cavity combustion chamber (5) has first and second nozzle hole groups whose inclination angles with respect to cylinder center axis line are different, one is large inclination angle and the other is small inclination angle. Nozzle hole diameter of second nozzle hole group is larger than that of the first one. First and second nozzle holes are alternately arranged in a circumferential direction. Glow plug (11) projects, in a height direction of cylinder (4), up to a height of spray center axis line (F2) of the second nozzle hole directed at a lower side, therefore glow plug (11) can contact fuel masses formed by sprays from both first and second nozzle holes. Glow plug (11) is positioned between spray center axis lines (F1, F2) in the circumferential direction, and positioned at swirl downstream side of spray center axis line (F2).

Abstract: An engine cooling system has an engine water jacket, a coolant circulation passage connecting a water jacket outlet to a water jacket inlet and a radiator disposed in the coolant circulation passage. A thermostat valve selectively closes and opens the coolant circulation passage leading to the radiator. A bypass passage extends from between the water jacket outlet and the thermostat valve to an outlet side of the radiator. A bridge passage connects a portion of the bypass passage to a portion of the coolant circulation passage located downstream of the radiator and upstream of where the bypass passage merges therewith. A resistance generating section is located downstream of the bridge passage connection to the coolant circulation passage and upstream of the bypass passage connection to the coolant circulation passage. The bridge passage has an oil heat exchanger to exchange heat between the cooling medium and transmission oil passing therethrough.

Abstract: An engine cooling system has an engine water jacket, a coolant circulation passage connecting a water jacket outlet to a water jacket inlet and a radiator disposed in the coolant circulation passage. A thermostat valve selectively closes and opens the coolant circulation passage leading to the radiator. A bypass passage extends from between the water jacket outlet and the thermostat valve to an outlet side of the radiator. A bridge passage connects a portion of the bypass passage to a portion of the coolant circulation passage located downstream of the radiator and upstream of where the bypass passage merges therewith. A resistance generating section is located downstream of the bridge passage connection to the coolant circulation passage and upstream of the bypass passage connection to the coolant circulation passage. The bridge passage has an oil heat exchanger to exchange heat between the cooling medium and transmission oil passing therethrough.