Patent ID: 8708256
Filing Date: 2014-04-29
Classification: F02B,F02M,Y02T

Abstract:
1. A fuel injection valve comprising: a nozzle body provided with a jet hole at an end portion of the nozzle body; a needle slidably arranged within the nozzle body, defining a fuel introduction path between the needle and the nozzle body, and provided with a seat portion seated on a seated position within the nozzle body, and provided with a first eccentricity suppression portion in a front end side of the needle; a rotational flow generation portion formed in an upstream side of the seat portion of the needle, and provided with a spiral groove giving a rotational component to a fuel introduced from the fuel introduction path; an air introduction path formed inside the needle; and a rotation stable chamber formed at the end portion of the nozzle body, the fuel that has passed through the rotational flow generation portion and the air that has passed through the air introduction path being introduced into the rotational stable chamber, wherein a diameter De of the rotation stable chamber satisfies the following equation: wherein Q is a greatest flow rate, θ is a spiral grove angle with respect to the horizontal direction at a terminal end of the spiral groove, Rs is a spiral groove area ratio, the spiral groove area ratio Rs=Sg/(CL+Sg), Rd is a rotation diameter ratio, the rotation diameter ratio Rd=Di/De, Di is a fuel introduction path diameter, Sg is the spiral groove area, and CL is an area defined between an outer circumferential wall surface of the first eccentricity suppression portion and an inner circumferential wall surface of the nozzle body, a total of the clearance CL and the spiral groove area Sg is a flow path area through which the fuel can flow from the fuel introduction path into the rotation stable chamber.