US 6,820,864 B2Granted

Fuel vaporization promoting apparatus and fuel carburetion accelerator

AssigneesHitachi, Ltd., Hitachi Car Engineering Co., Ltd.

InventorsKiyoshi Amou, Yuzo Kadomukai, Hiroaki Saeki, Kenji Watanabe, Takanobu Ichihara, Masami Nagano

Life of this patent

Estimating the term…

Loading patent…

Abstract

Atomization and vaporization of spray in a fuel supply system is promoted at the time of cold startup and the amount of fuel depositing on the inner wall of the intake manifold is reduced, thereby ensuring improved startability of an internal combustion engine of a car, reduced fuel costs and improved purification of exhaust gas. A very fine groove is formed on a heat transfer surface in a fuel vaporization promoting apparatus, wherein this groove is shaped in such a way that fuel is dispersed by the surface tension of the heat transfer surface and the fuel. This configuration ensures uniform dispersion of fuel on the heat transfer surface and effective promotion of vaporization.

Claims7

Dependent claims

A fuel vaporization promoting apparatus for vaporizing fuel by causing fuel spray injected from a fuel injection valve to impact on a heat transfer unit provided on the downstream side of said fuel injection valve;

said fuel vaporization promoting apparatus being characterized in that the surface of said heat transfer unit has an irregular shape,
wherein said irregular shape is formed of a groove provided on the surface of a cylindrical heat transfer unit, and the relationship of d<(σ/(ρ·g)·(Ls/S) holds among d, σ, ρ, g, and Ls, where d denotes the inner diameter of a cylindrical heat transfer unit, σ denotes a fuel surface tension, ρ denotes density, g denotes gravity acceleration, Ls denotes length of contact between heat transfer unit surface and fuel, and S denotes cross section of fuel stored in said groove.

Dependencies are inferred from the claim text.