Fuel injector

• US 20030127543A1
• Filed: 11/12/2002
• Published: 07/10/2003
• Est. Priority Date: 11/11/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Ludwig, Thomas, Sieber, Udo, Stein, Juergen, Huebel, Michael, Haag, Gottlob, Rieger, Franz, Brenner, Ulrich, Schlembach, Hans
• Granted Patent: US 6,814,309 B2
• Time in Patent Office: Days
• US Class Current: 239/584
• CPC Class Codes: F02M 53/04 Injectors with heating, cooling, or thermally-insulating means
• CPC Class Codes: F02M 61/04 having valves , e.g. having a plurality of valves in series
• CPC Class Codes: F02M 61/166 Selection of particular materials
• CPC Class Codes: F02M 61/18 Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
• CPC Class Codes: F02M 61/1806 characterised by the arrangement of discharge orifices, e.g. orientation or size
• CPC Class Codes: F02M 61/186 Multi-layered orifice plates
• CPC Class Codes: Y10T 137/7891 Flap or reed

Abstract

A fuel injector, in particular an injector for fuel injection systems in internal combustion engines, includes a valve needle (6) having a valve-closure member (7) which cooperates with a valve-seat surface (8) situated in valve-seat member (5) to form a sealing seat (9) and which has several injection orifices (4, 12) which are situated downstream from the sealing seat (9), and are sealed by sealing seat (9) against a fuel supply. A disk element (10) is arranged downstream from the sealing seat (9), the disk element (10) having at least one valve section (11), which changes its shape when the temperature changes. Valve section (11) is connected to a heating element (13) and is possibly covering an injection orifice (12).

Claims

1. A fuel injector, in particular an injector for fuel injection systems of internal combustion engines, having a valve-closure member (7), which cooperates with a valve-seat surface (8) in a valve-seat member (5) to form a sealing seat (9), several injection orifices (4, 12) being arranged downstream from the sealing seat (9), which are sealed from a fuel supply by the sealing seat (9),

wherein a disk element (10) is situated downstream from the sealing seat (9), the disk element (10) having at least one valve section (11) which changes its shape when the temperature changes, the valve section (11) being connected to a heating element (13), and the valve section (11) being able to cover an injection-orifice (12).

2. The fuel injector according to claim 1,

wherein at least the valve section (11) of the disk element (10) is made of a bimetal.

3. The fuel injector according to claim 2,

wherein the lamination of the bimetal causes the valve sections (11) of the disk element (10) to unblock the injection orifices (12) when heated.

4. The fuel injector according to claim 2,

wherein the lamination of the bimetal causes the valve sections (11) of the disk element (10) to cover the injection orifices (12) when heated.

5. The fuel injector according to claim 1,

wherein at least the valve section (11) of the disk element (10) is made of a shape memory alloy.

6. The fuel injector according to claim 5,

wherein the shape memory alloy has a two-way effect.

7. The fuel injector according to one of claims 1 through 6,

wherein the heating elements (13) include electric heating wires being arranged on the valve sections (11).

8. The fuel injector according to one of claims 1 through 7,

wherein the valve sections (11) are designed as radially inwardly oriented tongues (17) of the disk element (10) and a portion of the injection orifices (12) in an outer hole circle (19) is assigned to the valve sections (11) of the disk element (10).

9. The fuel injector according to claim 8,

wherein the injection orifices (4, 12) are arranged in an inner hole circle (18) and an outer hole circle (19) on valve seat member (5) or on an injection orifice plate (2).

10. The fuel injector according to one of claims 1 through 9,

wherein the injection orifices (4, 12) have different injection angles.

11. The fuel injector according to one of claims 1 through 10,

wherein the injection orifices (4, 12) have different opening diameters and/or different axial lengths.

12. The fuel injector according to one of claims 1 through 11,

wherein the valve-closure member (7) is actuatable via a valve needle (6) using an electromagnetic or a piezoelectric actuator.

13. The fuel injector according to one of claims 1 through 12,

wherein the injection orifices (4, 12) are formed in an injection orifice plate (2), which is firmly connected to a valve body (1) having the sealing seat (9).