Injector
AssigneeDenso Corporation
InventorsNoritsugu Kato, Hitoshi Shibata, Toyoji Nishiwaki
Life of this patent
Estimating the term…
Abstract
A fuel chamber defined by a recess portion of a valve body and a tip section of a valve member of an injector is structured such that a seat diameter Ds of a seat section of the valve member seated on a valve seat section formed on an inner peripheral surface of the valve body, an axial distance A between an inlet portion of an injection hole formed in the recess portion and the tip section of the valve member facing the inlet portion in the fuel chamber and an axial distance B between an inside region of the recess portion located radially inside the inlet portion of the injection hole in the fuel chamber and the tip section facing the inside region satisfy inequalities: 0.048≦A/Ds≦0.18 and B/Ds≦0.18.
Claims21
An injector comprising:
- a valve body having an inner peripheral surface, which defines a fuel passage and which has a diameter reducing downstream with respect to a fuel flow direction, a valve seat section formed on the inner peripheral surface, a recess portion provided downstream of the valve seat section with respect to the fuel flow direction and an injection hole formed in the recess portion;
- a valve member that is arranged in the valve body such that the valve member can reciprocate in an axial direction and that has an outer peripheral surface defining the fuel passage with the inner peripheral surface of the valve body, the valve member having a seat section formed on the outer peripheral surface such that the seat section can be seated on the valve seat section and can separate from the valve seat section and a tip section arranged downstream of the seat section with respect to the fuel flow direction to face the recess portion, wherein
- the injector injects the fuel, which flows into a fuel chamber defined by the recess portion and the tip section, through the injection hole when the seat section separates from the valve seat section,
- the valve body is structured such that a virtual extended line extending from an inner peripheral surface portion of the inner peripheral surface, which provides the valve seat section, in a diameter reducing direction of the inner peripheral surface portion, along which a diameter of the inner peripheral surface portion reduces, exists at an inlet portion of the injection hole and intersects with an injection hole inner peripheral surface of the injection hole on a virtual plane including a central axis of the injection hole, and
- the tip section of the valve member has an inclined surface spreading inward in an annular shape from a downstream end of the seat section, the inclined surface spreading radially inward further than a position where the central axis of the injection hole intersects with the tip section.
An injector comprising:
- a valve body having an inner peripheral surface, which defines a fuel passage and which has a diameter reducing downstream with respect to a fuel flow direction, a valve seat section formed on the inner peripheral surface, a recess portion provided downstream of the valve seat section with respect to the fuel flow direction and a plurality of injection holes formed in the recess portion;
- a valve member that is arranged in the valve body such that the valve member can reciprocate in an axial direction and that has an outer peripheral surface defining the fuel passage with the inner peripheral surface of the valve body, the valve member having a seat section formed on the outer peripheral surface such that the seat section can be seated on the valve seat section and can separate from the valve seat section and a tip section arranged downstream of the seat section with respect to the fuel flow direction to face the recess portion, wherein
- the recess portion and the tip section provide a fuel chamber substantially in a cylindrical shape,
- the injector injects the fuel, which flows into the fuel chamber when the seat section separates from the valve seat section, through the injection holes, and
- a seat diameter Ds of the seat section seated on the valve seat section, an axial distance A between an inlet portion of each of the injection holes and the tip section facing the inlet portion in the fuel chamber and an axial distance B between an inside region of the recess portion located radially inside the inlet portion of the injection hole in the fuel chamber and the tip section facing the inside region satisfy inequalities:
- 0.048≦A/Ds≦0.18;
- B/Ds≦0.18;
- B<A.
Dependencies are inferred from the claim text.