Fuel injector

Patent metadata

Field	Value
Publication number	US-10024273-B2
Application number	US-201615288933-A
Country	US
Kind code	B2
Filing date	Oct 7, 2016
Priority date	Oct 9, 2015
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A fluid injector is shown and described, including an injector housing and an armature which is coupled to a valve needle. A first bellow surrounds a first space. A first axial end of the first bellow is connected to the injector housing and a second axial end of the first bellow is connected to a first axial side of the armature. A second bellow surrounds a second space. A first axial end of the second bellow is connected to a second axial side of the armature and a second axial end of the second bellow is connected to the housing.

First claim

The invention claimed is:

1. A fluid injector for direct injection of compressed natural gas into a combustion chamber of a combustion engine, the fluid injector comprising:
an injector housing;
an injector inlet, an injector outlet and a fluid supply line extending along a longitudinal axis between the injector inlet and the injector outlet;
a coil;
a valve needle being axially moveable parallel to the longitudinal axis;
an armature mechanically coupled to the valve needle;
a first bellow surrounding a first space, wherein a first axial end of the first bellow is connected to the injector housing so that the first space is in fluid communication with the injector inlet, and wherein a second axial end of the first bellow is connected to a first axial side of the armature; and
a second bellow surrounding a second space, wherein a first axial end of the second bellow is connected to a second axial side of the armature, and wherein a second axial end of the second bellow is connected to the injector housing so that the second space is in fluid communication with a section of the fluid supply line, the section of the fluid supply line is adjacent to the injector outlet.

2. The fluid injector according to claim 1 , wherein the armature has at least one through-hole extending along the longitudinal axis, the second axial end of the first bellow is connected to the first axial side of the armature so that the first space is in fluid communication with the at least one through-hole, and the first axial end of the second bellow is connected to the second axial side of the armature so that the second space is in fluid communication with the at least one through-hole.

3. The fluid injector according to claim 1 , wherein an interior of the fluid supply line is sealed off from the coil, the connections at the first and second axial ends of each of the first and second bellows comprise hermetic welds, the hermetic welds comprising hermetic laser welds.

4. The fluid injector according to claim 1 , wherein the fluid injector comprises a valve assembly of the outward opening type.

5. The fluid injector according to claim 4 , wherein the valve assembly comprises a valve seat formed at the injector housing, and a closing member which is connected to or formed at an axial end of the valve needle.

6. The fluid injector according to claim 5 , wherein the valve seat comprises a first circular sealing surface, the closing member comprises a second circular sealing surface, and in a closed state of the valve assembly, the first circular sealing surface and the second circular sealing surface contact each other in a circular contact area which is closed at a circumference thereof, wherein the circular contact area, by extending along the circumference and by extending in a radial direction has a two-dimensional extension.

7. The fluid injector according to claim 1 , wherein the coil is a component of a solenoid circuit, the solenoid circuit comprising a dual pole solenoid circuit.

8. The fluid injector according to claim 1 , wherein a cross-section of the space of the second bellow exceeds a cross-section of the space of the first bellow.

9. The fluid injector claim 1 , wherein the first bellow and the second bellow are made of elastic material.

10. The fluid injector according to claim 1 , further comprising a first compression spring which is axially clamped between the first axial side of the armature and the injector housing.

11. The fluid injector according to claim 10 , further comprising an adjusting mechanism adjusting an axial compression of the first compression spring.

12. The fluid injector according to claim 11 , further comprising a second compression spring which is axially clamped between the second axial side of the armature and the injector housing.

13. The fluid injector according to claim 10 , wherein axial forces of the first bellow, the second bellow and the first compression spring are balanced to each other and to a predetermined gas pressure in the fluid supply line so that in a de-energized state of the coil, the armature is held axially movable in both axial directions in an axial distance away from the coil and away from a casing which surrounds the coil.

14. The fluid injector according to claim 1 , wherein the first bellow is circumferentially surrounded by a hollow cavity which is in fluid communication with a fluid connector of the injector housing, the fluid connector is connectable to a source of cooled fluid or to a source of heated fluid, and the second bellow is circumferentially surrounded by a hollow duct which is in fluid communication with a fluid connector of the injector housing, the fluid connector is connectable to a source of cooled fluid or to a source of heated fluid.

15. A fluid injector for direct injection of compressed natural gas into a combustion chamber of a combustion engine, comprising:
an injector housing;
a valve needle; and
a valve assembly of the outward opening type, the valve assembly comprises a valve seat formed at the injector housing, and a closing member which is connected to or formed at an axial end of the valve needle, wherein the valve seat comprises a first circular sealing surface, the closing member comprises a second circular sealing surface, and in a closed state of the valve assembly, the first circular sealing surface and the second circular sealing surface contact each other in a circular contact area which is closed at a circumference thereof, and the circular contact area, by extending along the circumference and by extending in a radial direction, has a two-dimensional extension, the circular contact area being ring shaped.

16. The fluid injector of claim 15 , wherein the circular contact area is in a plane that is perpendicular to a longitudinal axis of the fluid injector.

17. The fluid injector of claim 15 , further comprising:
an injector inlet and an injector outlet;
a fluid supply line;
an armature mechanically coupled to the valve needle;
a first bellow surrounding a first space, wherein a first axial end of the first bellow is connected to the injector housing, and wherein a second axial end of the first bellow is connected to a first axial side of the armature; and
a second bellow surrounding a second space, wherein a first axial end of the second bellow is connected to a second axial side of the armature, and wherein a second axial end of the second bellow is connected to the injector housing.

18. The fluid injector of claim 17 , wherein the first space is in fluid communication with the injector inlet, the second space is in fluid communication with a section of the fluid supply line, and the section of the fluid supply line is adjacent to the injector outlet.

19. The fluid injector according to claim 18 , further comprising a first compression spring which is axially clamped between the first axial side of the armature and the injector housing, wherein axial forces of the first bellow, the second bellow and the first compression spring are balanced to each other and to a predetermined gas pressure in the fluid supply line so that in a de-energized state of the coil, the armature is held axially movable in both axial directions an axial distance away from the coil and away from a casing which surrounds the coil.

20. The fluid injector according to claim 17 , wherein the first bellow is circumferentially surrounded by a hollow cavity which is in fluid communication with a fluid connector of the injector housing, the fluid connector is connectable

Assignees

• Continental Automotive Gmbh

Inventors

• Filippi Stefano
• Grandi Mauro
• Lenzi Francesco
• Polidori Valerio

Classifications

• F02M21/0269

  Outwardly opening valves, e.g. poppet valves · CPC title

• F02M21/0215 Primary

  Mixtures of gaseous fuels; Natural gas; Biogas; Mine gas; Landfill gas · CPC title

• F02M51/0607

  the actuator being hollow, e.g. with needle passing through the hollow space · CPC title

• F02M21/0254

  Electric actuators, e.g. solenoid or piezoelectric · CPC title

• F02M21/0257 Primary

  Details of the valve closing elements, e.g. valve seats, stems or arrangement of flow passages · CPC title