Fuel injector and method for manufacturing fuel injector

Patent metadata

Field	Value
Publication number	US-9828957-B2
Application number	US-201214345800-A
Country	US
Kind code	B2
Filing date	Sep 12, 2012
Priority date	Sep 20, 2011
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A fuel injector 100 includes a nozzle member 60 having a fuel passage 60 a leading to an injection port 60 b ; a valve main body 51 adapted to reciprocate for opening and closing the fuel passage 60 a ; an elastic portion 56 elastically deformable in closing the fuel passage 60 a by movement of the valve main body 51 in a closing direction, the elastic member being attached to one of the nozzle member 60 and the valve main body 51 and adapted to be abutted against the other of the nozzle member 60 and the valve main body 51 to close the fuel passage 60 a by moving the valve main body 51 in the closing direction; and a stopper 70 adapted to restrict movement of the valve main body 51 in the closing direction by being abutted against the valve main body 51 , the stopper 70 being formed of material different from the nozzle member 60.

First claim

The invention claimed is:

1. A fuel injector comprising:
a passage formation portion provided in a main body, the passage formation portion having a fuel passage leading to an injection port from which fuel is injected;
a valve member reciprocatingly accommodated in the main body, the valve member being adapted to open and close the fuel passage by reciprocating;
a valve seat formed at a peripheral edge of the fuel passage;
a rubber member that is attached to an end of the valve member in such a manner as to confront the valve seat, the rubber member being elastically deformable by a movement of the valve member in a valve closing direction in closing the fuel passage, the rubber member being adapted to close the fuel passage by being abutted against the valve seat when the valve member moves in the valve closing direction; and
a movement restricting portion provided in the main body for restricting the movement of the valve member in the valve closing direction by being abutted against the valve member, wherein
the movement restricting portion is formed of material different from the passage formation portion,
the movement restricting portion is formed in a cylindrical shape which has a first inner peripheral surface, a second inner peripheral surface, and a surface connecting the first inner peripheral surface to the second inner peripheral surface,
an inner diameter of the first inner peripheral surface is larger than an inner diameter of the second inner peripheral surface, and
the valve member is configured to abut the surface connecting the first inner peripheral surface to the second inner peripheral surface.

2. A fuel injector according to claim 1 , wherein
the movement restricting portion is abutted against the valve member in a position where a crushing margin of the elastic member elastically deformed reaches a predetermined value with a fuel passage closed by movement of the valve member to thereby restrict the movement of the valve member in the valve closing direction.

3. A fuel injector according to claim 1 , wherein
the passage formation portion is located downstream of the movement restricting portion with respect to a fuel flow toward the injection port within the main body.

4. A fuel injector according to claim 3 , wherein
the movement restricting portion is cylindrically formed to reciprocatingly accommodate the valve member on an inner periphery thereof, and
while the valve member is abutted against the movement restricting portion, a clearance is formed between an inner peripheral surface of the movement restricting portion and an outer peripheral surface of the valve member to allow fuel flow into the passage formation portion.

5. A fuel injector according to claim 3 , wherein
the elastic member is attached to the valve member,
the elastic member includes a seat portion protruding toward the passage formation portion on an outer peripheral surface of the elastic member opposed to the passage formation portion, and
the seat portion is abutted to enclose an outer periphery of an opening of the fuel passage on the valve member, so that the fuel passage is closed.

6. A fuel injector according to claim 5 , wherein
the seat portion has a recessed portion of which an inner peripheral surface is inclined such that the recessed portion becomes deeper toward a center in a radial direction of the recessed portion.

7. A fuel injector according to claim 3 , wherein
the elastic member is attached to the passage formation portion,
the elastic member has an opening leading to the fuel passage,
the valve member includes a seat portion protruding toward the elastic member on an outer peripheral surface of the valve member opposed to the elastic member, and
the seat portion is abutted to enclose an outer periphery of the opening, so that the fuel passage is closed.

8. A fuel injector according to claim 1 , wherein
the injection port is formed at a downstream end of the fuel passage.

9. A fuel injector according to claim 1 , wherein
the elastic member has an anchor portion fixed to one of the passage formation portion and the valve member in a direction to intersect a reciprocating direction of the valve body.

10. A fuel injector according to claim 1 , wherein
the main body is cylindrically formed, and has an opening formed at a downstream end with respect to fuel flow within the main body,
one of the movement restricting portion and the passage formation portion is disposed between one end and the other end of the main body in its axial direction, and
another of the movement restricting portion and the passage formation portion is formed of a material different from the main body, and is provided in the main body by being inserted into the opening and fixed to the opening.

11. A fuel injector according to claim 10 , wherein
one of the movement restricting portion and the passage formation portion is formed of a material different from the main body, and
a stepped portion is formed between the one end and the other end of the main body in its axial direction, and
another one of the movement restricting portion and the passage formation portion is abutted against the stepped portion to be positioned with respect to the main body.

12. A fuel injector according to claim 1 , wherein
the movement restricting portion is formed of a material different from the main body.

13. A fuel injector according to claim 1 , wherein
a part of the movement restricting portion abutted against the valve member is formed of a same material as that of a part of the valve member abutted against the movement restricting portion.

14. A fuel injector according to claim 13 , wherein
at least one of a part of the movement restricting portion abutted against the valve member, and a part of the valve member abutted against the movement restricting portion has a coated layer formed on a surface thereof.

15. A fuel injector according to claim 1 , wherein
the rubber contains fluoro-rubber.

16. A fuel injector according to claim 1 , wherein
a gas fuel flows into the main body.

17. A fuel injector according to claim 1 , further comprising:
a fixed core fixed to the main body;
a movable core reciprocatingly accommodated in the main body; and
an electromagnetic coil for generating an electromagnetic force so as to attract the movable core toward the fixed core, wherein
the valve member is coupled to the movable core so as to be relatively movable with respect to the movable core,
when the energization of the electromagnetic coil is started, the movable core is attracted and moved to the fixed core and the valve member moves in a valve opening direction, and
after the movable core is abutted against the fixed core, the valve member further moves in the valve opening direction.

18. A fuel injector according to claim 17 , wherein
until the movable core moves by a predetermined distance after a startup of the energization, the movable core moves without moving the valve member, and
until the movable core is abutted against the fixed core after moving by the predetermined distance, the movable core moves along with the valve member.

19. A fuel injector according to claim 1 , wherein
the valve member has a quadrangular prism portion, a columnar portion and a tapered surface connecting the quadrangular prism portion to the columnar portion.

20. A method for manufacturing a fuel injector,
the fuel injector including:
a passage formation portion provided in a main body, the passage

Assignees

• Fujino Tomoki
• Furukawa Takashi
• Hongo Yusuke
• Denso Corp

Inventors

• Fujino Tomoki
• Furukawa Takashi
• Hongo Yusuke

Classifications

• F02M51/0625 Primary

  characterised by arrangement of mobile armatures · CPC title

• F02M61/166

  Selection of particular materials · CPC title

• F02M61/1893

  Details of valve member ends not covered by groups F02M61/1866 - F02M61/188 · CPC title

• F02M51/0685

  the armature and the valve being allowed to move relatively to each other or not being attached to each other · CPC title

• F02M21/0269

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