Abstract: A fuel injection apparatus includes: an injector disposed at a position offset from an ignition plug toward an intake port and injecting a fuel spray toward a crown surface of a piston, and an injection controller causing the injector to perform injection in accordance with an amount and timing of fuel injection preset in accordance with an operating state of an engine. The piston includes: a first recess formed by recessing a central portion of the crown surface and a second recess formed by recessing part of the first recess on an injector side further than the first recess. The injector injects 50% or more of fuel to be injected for the last fuel injection toward the second recess during a compression stroke, and injects part of the fuel to be injected for the last fuel injection toward an area of the first recess other than the second recess.

Abstract: A piston is used for an engine including: an ignition plug disposed in the vicinity of a central axis of a cylinder; intake and exhaust ports disposed at positions where the ignition plug is interposed therebetween; and an injector disposed at a position offset from the ignition plug toward the intake port to inject fuel sprays toward a crown surface of the piston. The piston includes: a recess formed by recessing the crown surface of the piston with respect to other portions of the crown surface, in which the recess includes a step on an outer peripheral edge over the entire circumference thereof with respect to the other portions, and a pair of lateral sides formed straightly so as to extend substantially in parallel to a straight line connecting the injector and the ignition plug when seen in a direction of the cylinder axis.

Abstract: A fuel injection apparatus includes: an injector disposed at a position offset from an ignition plug toward an intake port and injecting a fuel spray toward a crown surface of a piston, and an injection controller causing the injector to perform injection in accordance with an amount and timing of fuel injection preset in accordance with an operating state of an engine. The piston includes: a first recess formed by recessing a central portion of the crown surface and a second recess formed by recessing part of the first recess on an injector side further than the first recess. The injector injects 50% or more of fuel to be injected for the last fuel injection toward the second recess during a compression stroke, and injects part of the fuel to be injected for the last fuel injection toward an area of the first recess other than the second recess.

Abstract: A piston is used for an engine including: an ignition plug disposed in the vicinity of a central axis of a cylinder; intake and exhaust ports disposed at positions where the ignition plug is interposed therebetween; and an injector disposed at a position offset from the ignition plug toward the intake port to inject fuel sprays toward a crown surface of the piston. The piston includes: a recess formed by recessing the crown surface of the piston with respect to other portions of the crown surface, in which the recess includes a step on an outer peripheral edge over the entire circumference thereof with respect to the other portions, and a pair of lateral sides formed straightly so as to extend substantially in parallel to a straight line connecting the injector and the ignition plug when seen in a direction of the cylinder axis.