Caterpillar Inc.

Nadeem N Bunni

Stephen Robert Lewis

Jayaraman Krishnapura Venkataraghavan

Dana Ray Coldren

Shriprasad Gaurishankar Lakhapati

Christopher D Hanson

Harish K Krishnaswamy

John McDonnell

Daniel Reese Puckett

Daniel Richard Ibrahim

Michael C Long

Avinash Reddy Manubolu

Jay Venkataraghavan

Mandar Arvind Joshi

Saboor Sheikh

Angela L Moore

Jayaramanaraman K Venkataraghavan

In one aspect, a fuel injector includes an injector body that defines a fuel inlet, a drain outlet and a nozzle outlet. A direct operated check valve is positioned in the injector body and includes a needle valve member with an opening hydraulic surface exposed to fluid pressure in a nozzle supply passage, and a closing hydraulic surface exposed to fluid pressure in a needle control chamber. The needle valve member is movable between a first position at which the nozzle supply passage is blocked to the nozzle outlet, and a second position at which the nozzle supply passage is open to the nozzle outlet. A needle control valve is positioned in the injector body and includes a control valve member movable between a first position at which the needle control chamber is fluidly connected to the drain outlet, and a second position at which the needle control chamber is fluidly blocked to the drain outlet. A solenoid actuator is positioned in the injector body and includes a stator assembly and an armature assembly coupled to the control valve member. One of the stator assembly and the armature assembly includes a non-magnetic insert that moves into and out of contact with another of the stator assembly and the armature assembly at an energized position and a de-energized position, respectively.

Solenoid actuator and fuel injector using same

An apparatus and method for controlling fluid flow is disclosed. An electromagnetic actuator may include a stator having an inner pole member and an outer pole member. The outer pole member may have a fluid passageway therein for transmitting fluid through the outer pole member. The actuator may further include a coil disposed around the inner pole member and arranged between the inner pole member and the outer pole member. The actuator may also include an armature moveable under the influence of a magnetic field generated by the stator and coil and operable to affect transmission of the fluid through the fluid passageway.

Electromagnetic actuator and method for controlling fluid flow

A solenoid actuated device such as a fuel injector includes an actuator body having a plurality of body pieces, and a single-pole solenoid actuator assembly positioned at least partially within the actuator body. The single-pole solenoid actuator assembly includes a one-piece compound armature housing having a load carrying component clamped between the first body piece and the second body piece, and a flux carrying component. The load carrying component includes a high structural strength and a low flux permeability, and the flux carrying component includes a low structural strength and a high flux permeability. A method of making a solenoid actuated device includes placing an armature at a sliding radial air gap with a flux carrying component of a one-piece compound armature housing, and establishing a structural load path by placing a load carrying component of the compound armature housing between a first actuator body piece and a second actuator body piece. A method of operating a single-pole solenoid actuator device includes supporting a flux carrying component of a one-piece compound armature housing with a load carrying component of the compound armature housing, channeling magnetic flux across a sliding air gap between a flux carrying component and the armature, and channeling a clamping load between a first actuator body piece and a second actuator body piece through the load carrying component of the compound armature housing.

Solenoid actuated device and methods

A solenoid actuator includes a stator assembly with a stator core of formed powder metal received in a stator housing. A ferromagnetic protective sleeve is in contact with and covers a majority of an inner end face and a cylindrical wall of the stator core, while a flux ring is in contact with and covers an outer end face of the stator core. An armature assembly includes an armature attached to a stem that is movable in an air gap relative to the ferromagnetic protective sleeve. A spring is operably positioned in the ferromagnetic protective sleeve but electrically isolated from the stator housing. The stator core is encapsulated to protect against erosion and fragmentation. A magnetic flux line around a solenoid coil passes through the stator core, the ferromagnetic protective sleeve, the armature, the flux ring and back to the stator core.

Protected powder metal stator core and solenoid actuator using same

An efficient control wave form is utilized to actuate the solenoids of a fuel system to reduce boost power/energy consumption. The solenoid is initially energized by applying a boost voltage from an electronic controller across a solenoid coil circuit. The electronic controller monitors the current level in the solenoid coil circuit, and changes to a reduced battery voltage when the current level in the solenoid coil circuit reaches a predetermined trigger current. The controller then maintains a pull-in current based upon battery voltage for a pull-in duration that initiates movement of the solenoid armature from an initial air gap position toward a final air gap position. After the pull-in duration, the current level is dropped to a hold in level for the remaining duration of the actuation event. The solenoid may be used for fuel injector control and/or pump control, such as to control fuel injection and pumping events respectively.

Efficient wave form to control fuel system

A fuel injector for a common rail fuel system includes a common rail inlet port fluidly connected to a high pressure common rail, and a cooling inlet fluidly connected to an output from a lower pressure fuel transfer pump. The cooling fluid circulates internally through the fuel injector to cool a single pole solenoid via both internal and peripheral cooling passages. In order to accommodate a small spatial envelope while providing superior performance, a thin insulating layer may separate the solenoid coil winding from an inner pole piece, and small flux gap clearances may permit a flux carrying portion of the injector body to be a portion of the single pole solenoid assembly.

Stator assembly and fuel injector using same

A self-guided armature assembly for a single pole solenoid assembly includes an armature stem and an armature. The solenoid assembly includes a flux ring component and an actuator body. The armature is movable inside the flux ring. An axial air gap is defined between the top armature surface of the armature and a bottom stator surface of a stator assembly. A sliding air gap is defined between an inner diameter surface of the flux ring and an outer diameter surface of the armature. The self-guided armature is guided along the flux ring via a guiding interaction between the armature and the flux ring. The sliding air gap is smaller than the axial air gap. A stem clearance gap is defined between the armature stem and the actuator body. The sliding air gap is also smaller than the stem clearance gap.

Self-guided armature in single pole solenoid actuator assembly and fuel injector using same

A solenoid assembly is disclosed. The solenoid assembly has a housing having a cavity disposed therein. The solenoid assembly also has a unitary stator having a plurality of separated portions. The separated portions are held together by at least one lip located on an outer periphery of the stator. The stator is sized to fit within the cavity disposed in the housing.

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Cranberry, PA, United States of America

Nadeem N Bunni