Fuel injection valve for internal combustion engines

Patent metadata

Field	Value
Publication number	US-9777684-B2
Application number	US-201314411895-A
Country	US
Kind code	B2
Filing date	May 15, 2013
Priority date	Jun 29, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

The invention relates to a fuel injection valve comprising a housing ( 1 ) in which pressure is applied to a nozzle needle ( 8 ), in a control chamber ( 28 ), at least indirectly with a closing force in the direction of a valve seat ( 10 ). The pressure in the control chamber ( 28 ) can be adjusted using a control valve ( 40 ) as said control chamber ( 28 ) is able to be connected to a low pressure chamber ( 46 ) via an outlet restrictor ( 31 ) and be filled with fuel at high pressure via an inlet restrictor ( 30 ). A longitudinally-displaceable control piston ( 29 ) is arranged in the control chamber ( 28 ) and divides said chamber ( 28 ) into a first control sub-chamber and a second control sub-chamber ( 228 ), the first control sub-chamber ( 128 ) being able to be connected to the low pressure chamber ( 46 ) by means of said outlet restrictor ( 31 ). A sealing surface ( 38 ) is formed on the control piston ( 29 ) and interacts with a sealing seat ( 39 ) in the control chamber ( 28 ) such that the inlet restrictor ( 30 ) is hydraulically disconnected from the second control sub-chamber ( 228 ) when the sealing surface ( 38 ) comes to rest against the sealing seat ( 39 ). Said first control sub-chamber ( 128 ) and second control sub-chamber ( 228 ) are constantly hydraulically interconnected by means of a restrictor connection ( 34 ).

First claim

The invention claimed is:

1. A fuel injection valve for internal combustion engines, having a housing ( 1 ) in which a nozzle needle ( 8 ) is at least indirectly subjected, by pressure in a control chamber ( 28 ), to a closing force in a direction of a valve seat ( 10 ), wherein the pressure in the control chamber ( 28 ) is adjustable by a control valve ( 40 ) by virtue of the control chamber ( 28 ) being connectable to a low-pressure chamber ( 46 ) via an outflow throttle ( 31 ) and the control chamber ( 28 ) being configured to be filled with fuel at high pressure via an inflow throttle ( 30 ),
wherein the control chamber ( 28 ) has therein a longitudinally movable control piston ( 29 ) which divides the control chamber ( 28 ) into a first control chamber part ( 128 ) and a second control chamber part ( 228 ), wherein the first control chamber part ( 128 ) is connectable to the low-pressure chamber ( 46 ) via the outflow throttle ( 31 ), and the control piston having a sealing surface ( 38 ) which interacts with a sealing seat ( 39 ) in the control chamber ( 28 ) such that, when the sealing surface ( 38 ) is in contact with the sealing seat ( 39 ), the inflow throttle ( 30 ) is hydraulically separated from the second control chamber part ( 228 ), and wherein the first control chamber part ( 128 ) and the second control chamber part ( 228 ) are permanently hydraulically connected to one another via a throttled connection ( 34 ), and
wherein the control piston ( 29 ) is subjected, by a spring element ( 33 ), to an opening force in a direction of the second control chamber part ( 228 ) and the spring element ( 33 ) is arranged in the second control chamber part ( 228 ).

2. The fuel injection valve as claimed in claim 1 , wherein the inflow throttle ( 30 ) issues into the second control chamber part ( 228 ) when the control piston ( 28 ) has lifted from the sealing seat ( 39 ).

3. The fuel injection valve as claimed in claim 1 , wherein the control chamber ( 28 ) is formed in a valve piece ( 20 ) in which the control piston ( 29 ) is guided.

4. The fuel injection valve as claimed in claim 3 , wherein the throttled connection ( 34 ) is formed in the valve piece ( 20 ).

5. The fuel injection valve as claimed in claim 1 , wherein the throttled connection ( 34 ) is formed in the control piston ( 29 ).

6. The fuel injection valve as claimed in claim 1 , wherein the control piston ( 29 ) delimits the first control chamber part ( 128 ) by way of a first face surface ( 36 ) and delimits the second control chamber part ( 228 ) by way of a second face surface ( 37 ), wherein the first and second face surfaces ( 36 ; 37 ) are situated opposite one another.

7. The fuel injection valve as claimed in claim 1 , wherein, on an outer wall of the control piston ( 29 ), there is formed an annular groove ( 49 ) into which the inflow throttle ( 30 ) issues.

8. The fuel injection valve as claimed in claim 7 , wherein the annular groove ( 49 ) is hydraulically separated from the second control chamber part ( 228 ) when the sealing surface ( 38 ) is in contact with the sealing seat ( 39 ).

9. The fuel injection valve as claimed in claim 1 , wherein the control piston ( 29 ), when in an open state, is pressed by the spring element ( 33 ) against a positionally fixed stop ( 35 ).

Assignees

• Bosch Gmbh Robert

Inventors

• Magel Hans-Christoph
• Gruenberger Andreas

Classifications

• F02M63/0075

  Stop members in valves, e.g. plates or disks limiting the movement of armature, valve or spring · CPC title

• F02M63/0043

  Two-way valves · CPC title

• F02M61/20

  Closing valves mechanically, e.g. arrangements of springs or weights {or permanent magnets; Damping of valve lift} · CPC title

• F02M2547/003

  Valve inserts containing control chamber and valve piston · CPC title

• F02M47/02 Primary

  of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure · CPC title