Caterpillar Inc.

Zhenlong Xu

Stephen Robert Lewis

Jayaraman Krishnapura Venkataraghavan

Avinash Reddy Manubolu

Shriprasad Gaurishankar Lakhapati

William J Love

Michael C Long

Jay Venkataraghavan

Christopher D Hanson

Kenneth Carroll Adams

Dianqi Fang

Lin Zhang

A common rail single fluid injection system including fuel injectors with the ability to produce multiple injection rate shapes. This is accomplished by including auxiliary filling orifices which selectively provide pressurized fluid to the check needle control chamber during injection events. In so doing, the speed and movement of the check needle is manipulated and differing injection rates may be achieved.

Fluid injector with auxiliary filling orifice

A piezoelectrically actuated device includes a body, a valve disposed within the body and an actuator for the valve, the actuator including a casing coupled with the body and a piezoelectric element disposed within the casing The actuator further includes a multi-function spring applying a preloading force to the piezoelectric element. The multi-function spring includes a first segment having a piston configured to translate a motion of the piezoelectric element during operation of the actuator, a second segment having at least one flexural element and a third segment having a first set of threads. The first set of threads is engaged with a second set of threads of the actuator and maintains the second segment in a tension state which corresponds with the preloading force.

Piezoelectric actuator with multi-function spring and device using same

A system for preloading piezoelectric actuators includes a fixture, a preloading mechanism configured to apply a mechanical force to a piezoelectric element supported by the fixture, and a sensor configured to sense an electrical property induced by the mechanical force in an electrical circuit having the piezoelectric element therein. A control device is coupled with the sensor and configured to generate a signal based on the sensed electrical property. A method of setting or testing preload includes applying a mechanical force to a piezoelectric element, and correlating an electrical property induced by the mechanical force with a magnitude of the mechanical force. Closed loop control allows preload to be set highly accurately.

System for preloading piezoelectric actuators and method

A fuel injector includes a fuel injector body defining a fuel inlet and at least one fuel outlet, a valve having a first valve state and a second valve state and an actuator for the valve. The fuel injector includes a biasing spring including a cylindrical rolled sheet having a first spring end, a second spring end and defining a longitudinal center axis. The cylindrical rolled sheet is configured to change in length to bias the actuator toward the first actuator position and includes a helical seam located between the first spring end and a second spring end which has a shape adapted to reduce non-uniformity in a spring constant via distributing stiffness about the longitudinal center axis.

Distributed stiffness biasing spring for actuator system and fuel injector using same

A fuel injector includes a body piece that defines a nozzle supply passage and a chamber in fluid communication therewith and configured to contain a fluid pressure within the fuel injector. The body piece has a threaded segment and a second, unthreaded segment that includes an outer surface of the fuel injector. A tip piece is clamped via a clamping piece to the body piece to form a fluid seal therewith, and a needle check extends within the body piece and the tip piece. The body piece is configured to contain fluid pressures, for example up to and exceeding 200 MPa, and has a wall thickness between the chamber and the unthreaded segment that is linked to a fluid pressure of fuel passing through the chamber. The fuel injector is configured via integrating portions of a nozzle case and a body guide to contain the extremely high fuel pressures.

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Peoria, IL, United States of America

Zhenlong Xu