Fuel injection valve
AssigneeDenso Corporation
InventorKoichi Sugiyama
Life of this patent
Estimating the term…
Abstract
In a fuel injection valve in which an outer frame member is press fitted to a limited region of an outer circumference of an inner pipe member in a state that a drive coil is radially sandwiched therebetween, a valve lift amount is accurately adjusted by press fitting the attracting member to the inner pipe member without being adversely affected by a possible deformation of the inner circumference of the inner pipe member on press fitting the outer frame member to the inner pipe member due to a relief space provided in the inner circumference of the inner pipe member for preventing the outer circumference of the attracting member from contacting the inner circumference of the inner pipe member at least at a position just radially inside and axially corresponding to the limited region.
Claims10
A valve for injecting fuel according to an axial reciprocal movement of a valve member, comprising:
- an inner pipe member having first and second zones through which magnetic flux easily passes and a third zone through which magnetic flux hardly passes, the third zone being positioned axially between the first and second zones;
- a drive coil arranged around an outer circumference of the inner pipe member;
- an outer frame member connected to an outer circumference of the inner pipe member at first and second limited regions falling within the first and second zones, respectively, in such a manner that the drive coil is sandwiched radially between the outer frame member and the inner pipe member;
- an attracting member press fitted to an inner circumference of the metal inner pipe member, an axial end of the attracting member being positioned axially within the third zone and other axial end thereof being positioned axially within the first zone;
- a moveable member with an axial end that is connected to the valve member, accommodated to move axially and reciprocatingly within the inner circumference of the inner pipe member, said axial end of the moveable member being positioned axially within the second zone and other axial end thereof being positioned axially within the third zone so that the movable member is axially away by a given distance from the axial end of the attracting member, when the drive coil is not energized, and attracted toward the axial end of the attracting member by magnetic flux flowing through the outer frame member, the first zone, the movable member and the second zone, when the drive coil is energized,
- wherein at least one of an outer circumference of the attracting member and the inner circumference of the inner pipe member is provided with a relief space which prevents the outer circumference of the attracting member from coming in contact with the inner circumference of the inner pipe member at a position just radially inside and axially corresponding to the first limited region.
Dependencies are inferred from the claim text.