Delphi Technologies, Inc.

Delphi Technologies Holding S.arl

Delphi International Operations Luxembourg S.a.r.l.

Daniel Jeremy Hopley

Louisa J Perryman

Martin A P Sykes

William Robert Burborough

Joseph Walsh

Adrian R Tolliday

Martin A Sykes

Peter Griffin

Peter J Spadafora

Robert Stephen Bond

Stephen Anthony Noyce

Robert Mark Kemsley

Colin Almond

A pump assembly includes a pump housing provided with a bore within which a pumping plunger is reciprocal along a plunger axis; a pump chamber defined at one end of the bore within which fuel is pressurized to a relatively high level; and an inlet valve housed within the pump housing and in communication with the pump chamber to control the flow of fuel into the pump chamber. A clamp member applies a clamping load to the pump housing, which has at least a component that is aligned with the plunger axis, through a surface of the pump housing located approximately axially above the bore. The clamp member may be secured to the pump housing by a securing member, which may be positioned radially outwards from the bore and extend through or below a plane through the pump chamber and perpendicular to the plunger axis through the pump chamber.

Pump assembly

A housing for use in high pressure fluid applications comprises a first drilling having a region of enlarged diameter bounded by an upper boundary in a first plane and a lower boundary in a second plane; and a second drilling intersecting with the first drilling via an intersection region. The intersection region includes a first substantially flat surface which defines a ceiling of the intersection region and which intersects the upper boundary of the region of enlarged diameter, and a second substantially flat surface which is opposed to the first substantially flat surface and which defines a floor of the intersection region and intersects the lower boundary of the region of enlarged diameter. As the flat surfaces are in alignment with a region of maximum hoop stress they do not act as a significant stress raiser at the intersection.

Housing with intersecting passages for high pressure fluid applications

A fault detection method is provided for detecting faults in an injector arrangement. The injector arrangement includes one or more piezoelectric fuel injectors connected in an injector drive circuit, and the injector drive circuit is arranged to control operation of the one or more piezoelectric fuel injectors. The fault detection method includes determining a sample voltage at a sample point in the injector drive circuit at a first sample time. The sample voltage is the voltage on an injector or is related to the voltage on an injector. The method further includes calculating a range of predicted voltages expected at the sample point at a second sample time following the first sample time, and determining the sample voltage at the sample point at the second sample time. The presence of a fault is detected if the sample voltage determined at the sample point at the second sample time is not within the range of predicted voltages.

Detection of faults in an injector arrangement

A method of operating a fuel injector including a piezoelectric actuator having a stack of piezoelectric elements, and wherein in use the injector communicates with a fuel rail, the method comprises: applying a discharge current to the actuator for a discharge period so as to discharge the stack from a first differential voltage level across the stack to a second differential voltage level across the stack; maintaining the second differential voltage level for a period of time; and applying a charge current to the actuator for a charge period so as to charge the stack from the second differential voltage level to a third differential voltage level; wherein the third differential voltage level is selected in dependence on at least two engine parameters, the at least two engine parameters selected from: rail pressure; the electric pulse time; and the piezoelectric stack temperature.

Injection control system

A method of identifying an individual short circuit fuel injector, within an injector bank of an engine comprising a plurality of fuel injectors. Each fuel injector has a piezoelectric actuator and an associated injector select switch forming part of an injector drive circuit. The method comprises: (i) charging all of the piezoelectric actuators of the plurality of fuel injectors within the injector bank during a charge phase; (ii) at the end of the charge phase waiting for a delay period; and (iii) subsequently closing an injector select switch of a fuel injector to select said fuel injector. The method further comprises: (iv) determining a stack voltage present on terminals of the piezoelectric actuator of the selected fuel injector and storing the stack voltage in a data store. The stack voltage is indicative of an amount of charge present on the selected injector at the end of the delay period. The method further comprises (v) repeating steps (i) to (iv) for each fuel injector in the injector bank in turn; and (vi) identifying the individual short circuit fuel injector as being the injector which has discharged beyond a predetermined voltage drop limit during the delay period. The method also comprises generating a short circuit fault signal for the identified fuel injector.

A method for controlling the displacement of a stack of a piezoelectric actuator for use in a fuel injector comprises determining a desired amount of charge (&#x394;Q) to be added or removed from the stack. The method further comprises determining an operating parameter of the fuel system and selecting a drive current level (PO, SO) and a drive time (t, t) in accordance with the desired amount of charge (&#x394;Q) and the operating parameter, and driving the drive current through the stack for the drive time (t, t) in order to add or remove the desired amount of charge (&#x394;Q).

Method of controlling a piezoelectric actuator

A method of operating a fuel injector having a piezoelectric actuator operable by applying a drive pulse thereto, wherein the drive pulse has a frequency domain signature. The method includes i) determining at least one resonant frequency of an injector installation in which the injector is received, in use, and ii) modifying the drive pulse such that a maximum of the frequency domain signature thereof is remote from the determined resonant frequency of the injector installation.

Method of operating a fuel injector

A method of detecting faults in an injector arrangement in an engine. The injector arrangement comprises at least one fuel injector having a piezoelectric actuator, and the method comprises: charging the piezoelectric actuator during a charge phase (t); attempting to recharge the piezoelectric actuator during a test phase (t) which commences after a time interval (&#x394;t) following the end of the charge phase (t); sensing a current (I) that flows through the piezoelectric actuator during the test phase (t); and generating a short circuit fault signal if the sensed current (I) reaches a first predetermined threshold current (I) which is indicative of a short circuit in the piezoelectric actuator.

The invention relates to a method of estimating the temperature of a piezoelectric actuator body for controlling the operation of a fuel injector mounted within an engine housing and supplied with fuel from a high pressure fuel pump. The piezoelectric actuator body is housed within a volume of fuel. The method comprises determining a temperature (T, T) of fuel upstream of the fuel volume, determining a temperature (T) of the engine housing, and estimating a temperature (T; T) of the piezoelectric actuator body based on the upstream temperature (T, T) and the temperature (T) of the engine housing. By considering the heat transfer between the piezoelectric actuator body, the injector and fuel within the volume, and the heat transfer due to fuel flow through the volume for an injection, the temperature of the piezoelectric actuator body can be estimated by modelling or mapping.

Piezo stack temperature estimator

An advance arrangement controls timing of fuel delivery by a fuel pump for use in an engine. The advance arrangement includes an advance piston, a servo piston, a light load piston, and an arrangement. The advance piston is slidable within a first bore and cooperates, in use, with a cam arrangement of a fuel pump to adjust the timing of fuel delivery by the pump. A surface associated with the advance piston is exposed to fuel pressure within a first control chamber. The servo piston is slidable within a further bore provided in the advance piston to control the pressure of fuel within the first control chamber. The servo piston is responsive to speed dependent fuel pressure variations within a servo control chamber, thereby to permit adjustment of the timing in response to engine speed. The light load piston is moveable relative to the advance piston against the action of a light load control spring in response to fuel pressure variations within a light load control chamber. The arrangement ensures the servo piston is substantially unresponsive to speed dependent fuel pressure variations within the servo control chamber, in circumstances in which fuel pressure within the light load control chamber is increased beyond a predetermined amount.

Advance arrangement

A pressure regulator for use in regulating the outlet pressure of a pump for use in an engine comprises a piston member which is moveable with respect to an outlet opening under the influence of fluid pressure acting on the piston member to control the degree by which the outlet opening is obscured. The pressure regulator comprises a biasing arrangement for applying a biasing force to the piston member which opposes the pressure of fluid acting on the piston member. The biasing arrangement comprises a moveable abutment member which is cooperable with a stop member so as to vary the rate at which the displacement of the piston member varies with fluid pressure acting on the piston member. The stop member is pre-set in a fixed position relative to the regulator housing such that movement of the abutment member is terminated when the abutment member is urged into engagement with the stop member. The invention also relates to a transfer pump comprising a pressure regulator.

Pressure regulator

An advance arrangement for use in controlling timing of fuel delivery by a fuel pump comprises an advance piston which is moveable within a first bore and which cooperates, in use, with a cam arrangement of a fuel pump to adjust the timing of fuel delivery by the pump, a surface associated with the advance piston being exposed to fuel pressure within an advance piston control chamber. The advance arrangement also includes a servo-piston which is slidable within a further bore provided in the advance piston to control the pressure of fuel within the advance piston control chamber, a surface associated with the servo-piston being exposed to fuel pressure within a servo control chamber. A non-drift arrangement, in the form of a drilling on or in the advance piston, is provided for preventing fuel pressure variations in the advance piston control chamber which would otherwise occur due to fuel leakage into or out of the advance piston control chamber whilst the servo control piston remains in a substantially fixed position. The advance arrangement may also include a damping arrangement for damping movement of the servo-piston in a direction to retard timing which occurs as a result of movement of the advance piston in a direction to advance timing at the end of a pumping event.

An advance arrangement for use in controlling timing of fuel delivery by a fuel pump comprises an advance piston which is moveable within a first bore and which cooperates, in use, with a cam arrangement of a fuel pump to adjust the timing of fuel delivery by the pump. A surface associated with the advance piston is exposed to fuel pressure within an advance piston control chamber. A light load piston is moveable relative to the advance piston against a spring load due to a light load control spring to adjust the timing under light load conditions. A temperature control valve is operable to control fuel pressure applied to the light load piston depending on engine temperature so as to permit adjustment of the timing depending on engine temperature. An adjustment piston co-operates with the light load control spring to vary the spring load acting on the light load piston in response to speed-dependent variations in fuel pressure applied to the adjustment piston, thereby to permit adjustment of the timing depending on engine temperature at relatively low engine speeds.

A mechanism for advancing and retarding the injection timing of a mechanically-actuated fuel injection pump. The mechanism includes a housing having a bore slidably receivable of an advance piston which cooperates with a lever of the fuel injector timing mechanism. A light load piston also in the bore cooperates with the advance piston to permit adjustment of timing under light load conditions. A rotatable cam mechanism cooperates with a flange on the light-load piston to set the axial rest position of the light-load piston and the advance piston, and hence the datum timing of the fuel injection pump. The cam may be easily set by external adjustment.

Growing community of inventors

Chislehurst, United Kingdom

Daniel Jeremy Hopley