Self-cleaning fuel injection valve

Claim 1

Fuel injection nozzle arrangement for an internal combustion engine, comprising: a nozzle body; an injection needle movably disposed in the nozzle body and engageable with a needle seat at the nozzle body, a pocket reservoir formed at the downstream end of the needle seat, injection holes with different injection directions extending from the pocket reservoir such that a bottom surface of the pocket reservoir lies below a level at which the injection holes open into said reservoir, allowing fuel to be trapped in said reservoir following an injection cycle; an abutment body movably disposed in the needle between a first position blocking the pocket reservoir and a second position freeing the pocket reservoir, said abutment body extending into an area of the reservoir adjacent to the injection holes to at least partially block said injection holes and to substantially fill said reservoir when said abutment body is in said first position; abutment body biasing means for biasing said abutment body toward said first position blocking the pocket reservoir, and; wherein said abutment body, injection needle and biasing means are configured so that said abutment body is removed to the second position prior to movement of the injection needle to begin the injection cycle, and wherein said abutment body is moved to the first position immediately following the injection cycle to force the trapped fuel from the reservoir.