Injection valve with single disc turbulence generation
A fuel injector for an internal combustion engine is disclosed. The fuel injector includes a housing, a valve seat, a metering orifice disc, and a needle. The housing has an inlet, an outlet, and a longitudinal axis extending therethrough. The valve seat is disposed proximate the outlet and includes a passage having a sealing surface and an orifice. The metering orifice disc is located at the outlet and has a plurality of metering openings extending therethrough. The needle is reciprocally located within the housing along the longitudinal axis between a first position wherein the needle is displaced from the valve seat, allowing fuel flow past the needle, and a second position wherein the needle is biased against the valve seat, precluding fuel flow past the needle. A generally annular channel is formed between the valve seat and the metering orifice disc. The channel tapers outwardly from a large height to a smaller height toward the orifice openings. A method of generating turbulence in a fuel flow through a fuel injector is also disclosed.
1. A method of controlling a spray of fuel flow through at least one metering orifice of a fuel injector, the method comprising:
providing the fuel injector having an inlet and an outlet and a passage extending along a longitudinal axis therethrough, the outlet having a seat and a metering disc, the seat having a seat orifice and a first channel surface extending obliquely to the longitudinal axis, a needle movable between first and second positions such that in the second position, the needle engages the seat so as to prevent fuel from passing through the seat orifice, the metering disc including a second channel surface confronting the first channel surface so as to provide an unobstructed flow channel that is separate from but in communication with the seat orifice, the metering disc having a plurality of metering orifices extending therethrough and located about the longitudinal axis, the metering orifices being in communication with the flow channel,
locating all of the metering orifices on a first virtual circle outside of a second virtual circle formed by a virtual extension of a sealing surface of the seat on the metering disc such that each of the metering orifices extends generally parallel to the longitudinal axis through the metering disc; and
imparting a radial velocity to the fuel flowing from the seat orifice through the flow channel so that fuel flows in transverse direction across and through the fuel metering orifices,
wherein the locating of the metering orifices includes spacing a first metering orifice at a first arcuate distance relative to a second metering orifice on the first virtual circle
wherein the imparting a radial velocity to the fuel flow includes configuring the flow channel to extend between a first position and a second position, the first position being located at a first distance from the longitudinal axis and at a first height at a point between the second channel surface of the metering disc and the first channel surface and the second position being located at a second distance from the longitudinal axis, different from the first distance, and a second height at another point between the second channel surface of the metering disc and the first channel surface, such that a product of the first distance and the first height is equal to the product of the second distance and second height.
2. The method of claim 1 , wherein the imparting comprises increasing the radial velocity between the seat orifice and each of the metering orifices.
3. The method of claim 1 , wherein the imparting comprises decreasing the radial velocity between the seat orifice and each of the metering orifices.