US 7,320,441 B2
Injection nozzle
Peter Boehland, Marbach (Germany)
Assigned to Robert Bosch GmbH, Stuttgart (Germany)
Appl. No. 10/549,577
PCT Filed Sep. 07, 2004, PCT No. PCT/DE2004/001978
§ 371(c)(1), (2), (4) Date Sep. 19, 2005,
PCT Pub. No. WO2005/052352, PCT Pub. Date Jun. 09, 2005.
Claims priority of application No. 103 52 504 (DE), filed on Nov. 11, 2003.
Prior Publication US 2006/0180679 A1, Aug. 17, 2006
Int. Cl. F02M 47/02 (2006.01); B05B 1/30 (2006.01); B05B 1/34 (2006.01)
U.S. Cl. 239—533.11  [239/88; 239/533.1; 239/533.12; 239/89; 239/92; 123/467; 123/299] 20 Claims
OG exemplary drawing
 
1. An injection nozzle for an internal combustion engine, in particular in a motor vehicle, the nozzle comprising,
a first nozzle needle, which is embodied in the form of a hollow needle and is able to control an injection of fuel through at least one first injection opening,
a second nozzle needle, which is situated coaxial to the first nozzle needle and is able to control the injection of fuel through the at least one second injection opening,
a control chamber,
a first control piston and a second control piston,
wherein the second control piston axially cooperates with the second nozzle needle or a second needle unit that includes the second nozzle needle,
an end surface of the second control piston oriented away from the injection openings being situated in the control chamber, thus permitting it to be acted on with the control pressure prevailing therein,
the second control piston resting axially against the second nozzle needle or second needle unit in a closed position of the second nozzle needle
the first control piston being embodied in the form of a hollow piston and cooperating axially with the first nozzle needle or a first needle unit containing the first nozzle needle,
the second control piston is situated coaxial to the first control piston,
a first control surface of the first control piston oriented away from the injection openings situated in the control chamber, thus permitting the control surface to be acted on with the control pressure prevailing therein,
an axial play between the first control piston and the first nozzle needle or first needle unit, in a closed position of the first nozzle needle
a throttle line providing communication between the control chamber and a pressure chamber, and
means for adjusting the pressure in the pressure chamber.