Fuel injection valve

Patent metadata

Field	Value
Publication number	US-11619200-B2
Application number	US-202016830780-A
Country	US
Kind code	B2
Filing date	Mar 26, 2020
Priority date	Sep 29, 2017
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A fuel injection valve includes a valve body, a fixed core, a movable core, a holder, and a stopper. The movable core has an inner core that contacts the stopper, and an outer core press-fitted to an outer peripheral surface of the inner core. The outer core has, in a moving direction of the movable core, a press-fit region which is press-fitted to the outer peripheral surface of the inner core, and a non-press-fit region which is not press-fitted to the outer peripheral surface of the inner core and is adjacent to the press-fit region in the moving direction. Between the inner peripheral surface of the holder and the outer peripheral surface of the movable core, the smallest gap in the press-fit region is larger than the smallest gap in the non-press-fit region.

First claim

What is claimed is:

1. A fuel injection valve comprising:
a valve body that opens and closes a nozzle hole for injecting a fuel;
a fixed core that generates a magnetic attraction force upon energization of a coil;
a movable core that has a cylindrical shape and opens the nozzle hole by moving together with the valve body by the magnetic attraction force;
a holder that has a movable chamber filled with the fuel, and accommodates the movable core movable in the movable chamber; and
a stopper that contacts the movable core to restrict movement of the movable core in a direction away from the nozzle hole, wherein
the movable core includes an inner core that contacts the stopper, and an outer core that is press-fitted to an outer peripheral surface of the inner core,
the outer core includes, in a moving direction of the movable core, a press-fit region in which the outer core is press-fitted to the outer peripheral surface of the inner core, and a non-press-fit region in which the outer core is not press-fitted to the outer peripheral surface of the inner core, the non-press-fit region being next to the press-fit region in the moving direction,
between an inner peripheral surface of the holder and an outer peripheral surface of the movable core, a smallest gap in the press-fit region is larger than a smallest gap in the non-press-fit region, and
a minimum inner diameter of a press-fit facing portion which is a portion of the holder facing an outer peripheral surface of the outer core in the press-fit region is larger than a minimum inner diameter of a non-press-fit facing portion which is a portion of the inner peripheral surface of the holder facing an outer peripheral surface of the outer core in the non-press-fit region.

2. The fuel injection valve according to claim 1 , wherein
an inner peripheral surface of the press-fit facing portion has a shape extending parallel to the moving direction,
an inner peripheral surface of the non-press-fit facing portion has a parallel surface extending in parallel to the moving direction, and a connection surface connecting the inner peripheral surface of the press-fit facing portion and the parallel surface, and
the connection surface has a shape which decreases in inner diameter in a direction toward the parallel surface.

3. The fuel injection valve according to claim 1 , wherein a maximum outer diameter of the outer core in the press-fit region is smaller than a maximum outer diameter of the outer core in the non-press-fit region.

4. The fuel injection valve according to claim 1 , wherein
the holder has a magnetic member having magnetism, and a non-magnetic member next to the magnetic member in the moving direction, and
an end face of the magnetic member and an end face of the non-magnetic member are welded to each other.

5. The fuel injection valve according to claim 1 , wherein the outer core has three or more through holes penetrating through the outer core in the moving direction and being arranged at regular intervals in a circumferential direction.

6. The fuel injection valve according to claim 1 , wherein the press-fit facing portion is arranged farther way from the nozzle hole in the moving direction than the non-press-fit facing portion.

Assignees

• Denso Corp

Inventors

• Yamamoto Shinsuke
• Mochizuki Kouichi

Classifications

• F02M63/0071

  characterised by guiding or centering means in valves including the absence of any guiding means, e.g. "flying arrangements" · CPC title

• F02M63/0075

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

• F02M51/0685 Primary

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

• F02M2200/8061

  involving press-fit, i.e. interference or friction fit · CPC title

• B05B1/3053

  the actuating means being a solenoid · CPC title