Injector with subdivided pressure multiplier

• US 20020084348A1
• Filed: 11/08/2001
• Published: 07/04/2002
• Est. Priority Date: 11/08/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Boecking, Friedrich
• Granted Patent: US 6,550,454 B2
• Time in Patent Office: Days
• US Class Current: 239/96
• CPC Class Codes: F02M 57/025 hydraulic, e.g. with pressure amplification
• CPC Class Codes: F02M 57/026 Construction details of pressure amplifiers, e.g. fuel passages or check valves arranged in the intensifier piston or head, particular diameter relationships, stop members, arrangement of ports or conduits

Abstract

An injector for injection a fuel under high pressure into a combustion chamber of an internal combustion engine, the injector has an injector housing, a control chamber, a primary-side inlet to the control chamber, a control valve which controls the primary-side inlet to the control chamber, a pressure multiplier movable in the injector housing, the pressure multiplier being formed as a two-part piston arrangement.

Claims

1. An injector for injection a fuel under high pressure into a combustion chamber of an internal combustion engine, the injector comprising an injector housing;

a control chamber;

a primary-side inlet to said control chamber a control valve which controls said primary-side inlet to said control chamber, a pressure multiplier movable in said injector housing, said pressure multiplier being formed as a two-part piston arrangement.

2. An injector as defined in claim 1, wherein said piston arrangement has an outer piston and an inner piston inserted in said outer piston.

3. An injector as defined in claim 2, wherein said outer piston and said inner piston are axially pretensioned relative to one another;

and further comprising means for axially pretensioning said outer piston and said inner piston relative to one another.

4. An injector as defined in claim 3, wherein said means for axially pretensioning include a spring element which is provided between a lower end surface of a screw-in element and an end side of said inner piston.

5. An injector as defined in claim 3, wherein said means for axial pre-tensioning include a screw-in element providing the pre-tensioning between said outer piston and said inner piston.

6. An injector as defined in claim 2, wherein said inner piston is guided in said outer piston with a radial play.

7. An injector as defined in claim 2, wherein said housing has two halves, said outer piston being arranged in one of said halves of said housing, while said inner piston has a shaft and is arranged with said shaft in another half of said housing.

8. An injector as defined in claim 2, wherein said pistons of said piston arrangement are radially oriented relative to one another in said injector housing which is separated along a separation joint.

9. An injector as defined in claim 2;

and further comprising a spring element which is supported in said injector housing and pretensions said outer piston against said control chamber.