US 12,234,795 B2
Fuel injector
Michael Leukart, Dusslingen (DE); Fabian Wolf, Renningen (DE); Ferdinand Nicolai, Stuttgart (DE); and Ulrich Lessing, Weiler Im Allgaeu (DE)
Assigned to Robert Bosch GmbH, Stuttgart (DE)
Appl. No. 17/627,955
Filed by Robert Bosch GmbH, Stuttgart (DE)
PCT Filed Jul. 8, 2020, PCT No. PCT/EP2020/069222
§ 371(c)(1), (2) Date Jun. 3, 2022,
PCT Pub. No. WO2021/008961, PCT Pub. Date Jan. 21, 2021.
Claims priority of application No. 10 2019 210 551.3 (DE), filed on Jul. 17, 2019.
Prior Publication US 2022/0298999 A1, Sep. 22, 2022
Int. Cl. F02M 61/18 (2006.01); F02M 61/04 (2006.01); F02M 61/12 (2006.01)
CPC F02M 61/1886 (2013.01) [F02M 61/042 (2013.01); F02M 61/12 (2013.01); F02M 61/1893 (2013.01); F02M 2200/06 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A fuel injector (10) comprising
a nozzle body (12), in which a blind hole (19) is formed, wherein at least one injection opening (14) leads off from the blind hole,
a nozzle needle (25; 25a to 25c), configured to be moved in a reciprocating manner along a longitudinal axis (18), wherein the nozzle needle (25; 25a to 25c) has a valve seat surface (29), which forms a sealing seat (26) with a seat surface (21) in the nozzle body (12) in a lowered position of the nozzle needle (25; 25a to 25c), and
at least one bore (34; 34a to 34c) in the nozzle needle (25; 25a to 25c), wherein at least some portions of a bore inlet (36) of the at least one bore (34; 34a to 34c) are arranged in a region of the seat surface (21) when the sealing seat (26) is formed, and a bore outlet of the at least one bore (34; 34a to 34c) is arranged below the valve seat surface (29) of the nozzle needle (25; 25a to 25c) in a direction of the longitudinal axis (18),
wherein the nozzle needle (25; 25a to 25c) has, from a region of the valve seat surface (29) to a flat end face (30) facing the blind hole (19), a frustoconical needle tip (28) with a constant angle (γ), wherein the bore inlet (36) extends from the region of the valve seat surface (29), and wherein the blind hole (19) has, in a region of the sealing seat (26), a section with a first angle (β1) with respect to the longitudinal axis (18), which is adjoined in the direction of a blind hole bottom (23) by a section (22) with a second angle (β2), wherein the second angle (β2) is smaller than the first angle (β1) in relation to the longitudinal axis (18).