Fuel injection system for internal combustion engines

• US 6,745,750 B2
• Filed: 11/25/2002
• Issued: 06/08/2004
• Est. Priority Date: 12/07/2000
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Egeler, Hansjoerg, Kahleyss, Ingolf, Kanne, Sebastian, Brenk, Achim, Mack, Manfred, Klenk, Wolfgang, Teschner, Werner, Boehland, Peter, Ferraro, Giovanni, Egler, Walter, Gordon, Uwe
• Primary Examiner(s): Gimie, Mahmoud
• Application Number:
  US10/182,561
• Publication Number:
  US 20030127074A1
• Time in Patent Office: 561 Days
• Field of Search: 123/447, 123/467, 123/446, 123/506, 239/88
• US Class Current: 123/447
• CPC Class Codes: F02M 2200/315 for damping fuel pressure fluctuations
• CPC Class Codes: F02M 2200/40 Fuel-injection apparatus with fuel accumulators, e.g. a fuel injector having an integrated fuel accumulator
• CPC Class Codes: F02M 55/04 Means for damping vibrations or pressure fluctuations in injection pump inlets or outlets
• CPC Class Codes: F02M 61/16 Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
• CPC Class Codes: F02M 63/0007 using electrically actuated valves injection valves F02M51/06
• CPC Class Codes: F02M 63/0225 Fuel-injection apparatus having a common rail feeding several injectors F02M63/0003 takes precedence; Means for varying pressure in common rails; Pumps feeding common rails

Abstract

A fuel injection system, having a fuel injection valve and a control valve, which control valve has a control valve member that is longitudinally displaceable in a control valve bore. A control valve sealing face is embodied on the control valve member; it cooperates with a control valve seat and thus controls the communication between a first pressure space and a second pressure space; the first pressure space communicates with a high-pressure collection chamber. In a valve body, a bore is embodied in which a pistonlike valve needle, with its end toward the combustion chamber, controls the opening of at least one injection opening by executing a longitudinal motion in response to the pressure in a pressure chamber; the pressure chamber communicates with the second pressure space via an inlet conduit. The first pressure space communicates via a throttle with a damping chamber, embodied as a blind bore and otherwise closed off, as a result of which pressure fluctuations that occur upon closure of the control valve are rapidly damped.

Claims

1. A fuel injection system for internal combustion engines, comprising

a fuel injection valve, which is supplied from a high-pressure fuel source and has a valve member (32) that is adjustable by means of the pressure of a pressure chamber (31) embodied in the fuel injection valve and as a result controls at least one injection opening (38) that can be made to communicate with the pressure chamber (31),

a control valve (50), which has a control valve member (54) that in a first position disconnects a first pressure space (57), communicating constantly with the high-pressure fuel source, from an inlet bore (28) leading to the pressure chamber (31) and in a second position opens the communication between the high-pressure fuel source and the pressure chamber (31), and

a line (71) having a throttle (72) between the high-pressure fuel source and the first pressure space (57), the line (71) leading to an otherwise closed-off damping chamber (70), the damping chamber (70) being embodied as a blind bore.

2. The fuel injection system of claim 1 wherein the line (71) leads from the first pressure space (57) to the damping chamber (70).

3. The fuel injection system of claim 1 wherein the fuel injection valve has a control valve body (17), a valve holding body (22), and a valve body (25), the control valve body (17) and the valve body (25) being disposed on opposite face ends of the valve holding body (22), the control valve (50) being disposed in the control valve body (17), and the valve member (32) being disposed in the valve body (25).

4. The fuel injection system of claim 3 wherein the control valve body (17) is axially braced against the valve holding body (22), and the damping chamber (70) is embodied in the valve holding body (22).

5. The fuel injection system of claim 4 wherein the throttle (72) is disposed in the control valve body (17).

6. The fuel injection system of claim 4 wherein the throttle (72) is disposed in the valve holding body (22).

7. The fuel injection system of claim 4 further comprising a shim (19) in which the throttle (72) is embodied, the shim being disposed between the control valve body (17) and the valve holding body (22).

8. The fuel injection system of claim 1 wherein at least two throttles (72) are disposed in the line (71).

9. The fuel injection system of claim 8 wherein the throttles (72) are embodied by bores in throttle disks (74), and the throttle disks (74) are disposed in the same radial plane as the line (71).

10. The fuel injection system of claim 9 wherein the throttles (72) are disposed offset from one another in the radial direction of the throttle disks (74).

11. The fuel injection system of claim 4 wherein the damping chamber (70) comprises two bore portions (170;

270) parallel to one another, the two bore portions communicating with one another.

12. The fuel injection system of claim 11 wherein both bore portions (170;

270) of the damping chamber (70) communicate through a transverse connection embodied in the valve holding body (22).

13. The fuel injection system of claim 11 wherein the valve body (25) is axially braced against the valve holding body (22) with the interposition of a valve shim (24), and wherein a transverse connection (85) that connects the bore portions (170;

270) of the damping chamber (70) to one another is embodied in the valve shim (24).

14. The fuel injection system of claim 1 wherein the control valve body (17) is fabricated from a harder steel than the valve holding body (22).

15. The fuel injection system of claim 3 wherein the control valve body (17) is fabricated from a harder steel than the valve holding body (22).

16. The fuel injection system of claim 4 wherein the control valve body (17) is fabricated from a harder steel than the valve holding body (22).

17. The fuel injection system of claim 9 wherein the control valve body (17) is fabricated from a harder steel than the valve holding body (22).

18. The fuel injection system of claim 1 wherein the high-pressure fuel source is a high-pressure collection chamber (10).

19. The fuel injection system of claim 14 wherein the high-pressure fuel source is a high-pressure collection chamber (10).

20. The fuel injection system of claim 15 wherein the high-pressure fuel source is a high-pressure collection chamber (10).