EP2639442A1

EP2639442A1 - Fuel injector

Info

Publication number: EP2639442A1
Application number: EP13460013.9A
Authority: EP
Inventors: Oleh Klyus
Original assignee: Akademia Morska W Szczecinie
Current assignee: Akademia Morska W Szczecinie
Priority date: 2012-03-15
Filing date: 2013-03-08
Publication date: 2013-09-18
Also published as: PL220085B1; PL398468A1

Abstract

A fuel injector, with a body (1), closing element in the shape of a needle (2) and direct fuel delivery passages (3), characterized by the fact that there is an additional element (5) - thin-walled cylinder - situated between the needle and an injector body (1). The needle (2) and additional element (5) have rough, threaded or corrugated surfaces (4). The additional element (5) may also have a form of a spring, spiral or porous structure made of wires or tiny balls. The surface of the non-working part of the needle (2) and the additional element (5) are covered with a catalytic material.

Description

The subject of the present invention is a fuel injector, serving for delivery into a combustion chamber a uniformly atomized fuel mixture that first undergoes catalytic and turbulizing treatment directly in the injector body. Such an injector may be used in internal combustion engines and other machines where fuel injection takes place.
There is known a fuel injector, composed of an atomizer which includes a needle with a conical tip that fits a seat (Jan. A. Wajand, Ttokowe Silniki Spalinowe, WNT, Warsaw, 2005). At its lower part the needle abruptly changes its dimension to a diamater smaller than a guide diameter. The whole needle is pressed by a pin and a controllable pressure spring to the seat. Fuel flows through holes drilled at an oblique angle to the fuel chamber, surrounding the lower part of the needle, where it acts on the ring-shaped surface of the needle. When fuel pressure overcomes the spring resistance, the needle rises, thus allowing to inject fuel into the combustion chamber. The moment pressure drops in the fuel discharging passage, the needle under the spring returns to rest in the seat and blocks the injection.
There is also known a fuel injector (patent description PL-204690 ) with a body having passages, in which elements in the shape of balls or wire covered with catalytic material are placed. The presence of a catalyst enables preliminary fuel treatment, resulting in dehydrogenation, which in turn shortens delay length of the self-ignition, and consequently, reduces fuel consumption, as well as the level of exhaust gas toxic emissions of an internal combustion engine.
There are known fuel injectors (patent description PL-205428 and patent description PL-205429 ) in which the effect of catalytic treatment is enhanced, because they utilize the phenomenon of turbulization of fuel flowing along elements with catalytic material deposited on their surface.
The fuel injector, subject of the present invention, has a fuel atomizer, in which a needle is placed, composed of a lower, non-working part and an upper part. The invention is characterized by an additional element fitted between the injector body and the lower needle part of the atomizer. That element as well as the needle have surfaces allowing to turbulize flowing fuel, while the catalyst covering the element and the needle is used to induce the chemical reaction known as dehydrogenation. This additional element has a shape of a thin-walled cylinder with a rough, threaded or corrugated surface. It can have a form of a spring, spiral or porous structure made of pressed wires or balls, enabling turbulization. The needle space and the additional element are situated in the thermally most loaded place of the injector. Catalytic material is deposited on the surfaces of elements forming the needle space - injector body, additional element and the needle. The catalytic material can be one of platinum group metals. The non-working surface of the needle and the additional element may have extra notches or elements (for instance, in the form of outstanding wires or threaded, to have increased roughness), resulting in an increased catalyst-fuel contact, as well as flowing fuel turbulization that additionally enhances the frequency of fuel-catalyst contacts.
The cross-section of the subject of the present invention is presented graphically.
The fuel injector has an atomizer body 1, the closing element in the form of a needle 2 and passages for direct fuel delivery 3. The needle surface is rough, corrugated or threaded surface 4, and there is an additional element 5, a thin-walled cylinder, between the needle and the injector body. The additional element 5 may also have a form of a spring, spiral or tiny balls, as these cause the phenomenon of turbulization. The surfaces of the non-working part of the needle 2 and the additional element 5 are covered with catalytic material. Moreover, the surface of the additional element 5 is rough, threaded or corrugated.
The injector operation is as follows:

Fuel is discharged by an injection pump to the atomizer through feeding passages 3 and further to the combustion chamber. While flowing, fuel is in contact with catalytic material and undergoes turbulization due to rough or corrugated surface or turbulizing passages 4 on the needle surface and rough or corrugated surface or turbulizing passages of the additional element 5. Fuel flowing through the atomizer gets in contact with a catalyst layer deposited on the passages, which enables preliminary fuel treatment, while fuel turbulization occurring while the fuel flows through along the needle 2 and additional element 5 enhances the frequency of fuel-catalyst contact.

The best engine performance over a wide load range is obtained due to the fact that fuel is affected by the catalyst whose effectiveness is increased by high temperature of injector elements and fuel flow turbulization.

Claims

A fuel injector with a fuel atomizer, wherein an additional element (5) in the form of a thin-walled cyclinder is placed between a needle (2) and an injector body (1), with passages for direct fuel delivery (3), and a non-working part of the needle (2) and the additional element (5) are covered with catalytic material, whereas needle (2) and additional element (5) have rough, threaded or corrugated surfaces (4) that enable the turbulization of flowing fuel.
The fuel injector of claim 1, wherein the additional element has a shape of a spring.
The fuel injecotr of claim 1, wherein the additional element has a spiral shape.
The fuel injecotr of claim 1, wherein the additional element has a form of a porous structure.