Fuel injection valve for internal combustion engines

• US 6,540,161 B1
• Filed: 12/26/2001
• Issued: 04/01/2003
• Est. Priority Date: 09/30/1999
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Gordon, Uwe
• Primary Examiner(s): Mar, Michael
• Assistant Examiner(s): Nguyen, Dinh Q.
• Application Number:
  US09/856,970
• Time in Patent Office: 461 Days
• Field of Search: 239/88-92, 239/96, 239/533--53, 123/467
• US Class Current: 239/533.3
• CPC Class Codes: F02M 2200/304 using hydraulic means
• CPC Class Codes: F02M 45/08 Injectors peculiar thereto
• CPC Class Codes: F02M 61/161 Means for adjusting injection-valve lift
• CPC Class Codes: F02M 61/182 Discharge orifices being situated in different transversal planes with respect to valve member direction of movement
• CPC Class Codes: F02M 61/20 Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift

Abstract

A fuel injection valve for internal combustion engines, having a valve body in which a valve member is disposed, which valve member changes into a spring plate, which is disposed in a spring chamber that receives the closing spring provided with a valve stop face on an end face. A control piston is provided defining a hydraulic control chamber, which control piston protrudes into the spring chamber, whose end face toward the combustion chamber forms a stroke stop face. As a function of pressure in the control chamber, the control piston can be moved counter to the closing force of a restoring spring from a first stroke position, remote from the valve member, toward the valve member into a second stroke position, where the control piston limits the maximum opening stroke (h) of the valve member to a partial stroke (h_T).

Claims

1. In a fuel injection valve for internal combustion engines, having a valve body (1), in which a bore (11) formed as a blind bore is embodied so that toward a combustion chamber it changes into a slide portion or bore (111), on a wall of which at least one injection opening (16, 17) is disposed, and having a pistonlike valve member (10), which is guided in a region of the bore (11) remote from the combustion chamber and is axially movable counter to the force of at least one closing spring (33) and which on its end toward the combustion chamber changes into a closing head (13) that is guided in the slide portion or bore (111) of the bore (11) and that closes the injection opening (16, 17), the injection opening (16, 17) being openable entirely or in part by an inward-oriented opening stroke motion of the valve member (10), as a result of which an injection cross section changes as a function of an opening stroke of the valve member (10), which valve member (10), for limiting its opening stroke motion to a maximum opening stroke (h) comes to rest on a stop, and on which valve member a pressure shoulder (24) acting in an opening direction is embodied, the improvement comprising, in a region of the valve body (1) remote from the combustion chamber, a control piston (43) is disposed at least approximately coaxially to the valve member (10), the control piston being guided axially movably in a control bore (57) embodied in the valve body (1) and defining a control chamber (56), and fuel under pressure can be delivered to the control chamber (56), by means of which the control piston (43) can be moved, counter to a force of a restoring spring (53), from a first stroke position toward the valve member (10) into a second stroke position, as a result of which the control piston (43) acts as a stop (44) for the valve member (10) and limits the opening stroke motion of the valve member (10) to a partial stroke (h_T) that is less than the maximum stroke (h).

2. The fuel injection valve of claim 1, wherein the maximum stroke (h) of the valve member (10) in the first stroke position of the control piston (43) is formed by a stroke stop (15) embodied rigidly on the valve body (1).

3. The fuel injection valve of claim 1, wherein the control piston (43), in its second stroke position, acts as a stop for the valve member (10) to limit the opening stroke motion of the valve member to the partial stroke (h_T).

4. The fuel injection valve of claim 1, wherein the control piston (43) is embodied in two parts, and a first part forms a hydraulic piston (46) and defines the control chamber (56), and a second part, which is connected to the hydraulic piston (46), is embodied as a thrust rod (49), which acts as the stop (44) for the valve member (10).

5. The fuel injection valve of claim 4, wherein the restoring spring (53) is braced on the hydraulic piston (46).

6. The fuel injection valve of claim 4, wherein the restoring spring (53) is braced on the thrust rod (49).

7. The fuel injection valve of claim 1, wherein the control piston (43), in its second stroke position, defines the opening stroke of the valve member (10) to the partial stroke (h_T) that amounts to approximately 40-60% of the maximum opening stroke (h), and preferably approximately 50%.

8. The fuel injection valve of claim 1, wherein in the wall of the slide bore (111), at least two injection openings (16, 17) are embodied, axially offset from one another.

9. The fuel injection valve of claim 8, wherein in the limitation of the opening stroke of the valve member (10) to the partial stroke (h_T), only one injection opening (17) is opened.

10. The fuel injection valve of claim 8, wherein the closing head (13) at the maximum opening stroke (h) of the valve member (10) opens both injection openings (16, 17) one after the other in the course of the opening stroke motion.

11. The fuel injection valve of claim 1, wherein the closing head (13), upon a limitation of the opening stroke to the partial stroke (h_T) in the opening stroke motion of the valve member (10), opens the at least one injection opening (16, 17) only partially.

12. The fuel injection valve of claim 1, wherein the fuel injection valve communicates via a high-pressure inlet line (66) with a high-pressure collection chamber (68).

13. The fuel injection valve of claim 12, wherein the control chamber (56) communicates, via an inlet bore (60) embodied in the valve body (1) and via a fuel inlet valve (62), with a control line (70) that communicates with the high-pressure collection chamber (68) via a control valve (73).

14. The fuel injection valve of claim 13, wherein the control line (70) can be relieved to a fuel tank (80) via a relief valve (76).