Fuel injection pump

Claim 2

In a fuel injection system having a pump for delivering fuel to an injection nozzle, an accumulator and pressure regulator for controlling delivery of fuel from said pump to said nozzle and comprising a housing defining a chamber for receiving fuel from said pump and having an open end and a closed eNd, said housing further defining a fuel delivery outlet extending from said chamber for delivering fuel to said nozzle and a pressure relief outlet extending from said closed end of said chamber for discharging excess fuel received from said pump, a rolling diaphragm closing said open end of said chamber and movable away from said closed end of said chamber in response to an increase in fuel pressure within said chamber, means biasing said diaphragm toward said closed end of said chamber, a bracket secured to said diaphragm within said chamber and engageable with said closed end of said chamber for limiting movement of said diaphragm theretoward, a valve member disposed in said chamber and engageable with said pressure relief outlet for controlling flow therethrough, means biasing said valve member away from said diaphragm toward engagement with said pressure relief outlet, said valve member including means engageable with said bracket after said diaphragm and said bracket move a selected distance away from said closed end of said chamber to thereby disengage said valve member from said pressure relief outlet, whereby initial displacement of said diaphragm less than said selected distance in response to an increase in fuel pressure within said chamber increases the amount of fuel accumulated in said chamber, whereby additional displacement of said diaphragm greater than said selected distance in response to an increase in fuel pressure within said chamber effects disengagement of said valve member from said pressure relief outlet to prevent further increase in pressure within said chamber, and whereby return of said diaphragm toward said closed end of said chamber upon a decrease in fuel pressure within said chamber discharges the increased amount of fuel accumulated within said chamber through said fuel delivery outlet for delivery to said nozzle.

Claim 3

The accumulator and pressure regulator of claim 1 wherein said bracket has a plurality of slots and said valve member has projections received in said slots whereby said valve member may be engaged by said bracket after said diaphragm and said bracket move said selected distance.

Claim 4

The accumulator and pressure regulator of claim 1 which further comprises means for applying a bias pressure against said diaphragm in opposition to the fuel pressure.

Claim 5

In a fuel injection system, a pump for delivering fuel to an injection nozzle comprising a stator defining a stator chamber, a cylindrical rotor disposed within said stator chamber, a slider reciprocably disposed within said stator chamber and having a cylindrical pumping chamber receiving said rotor, said slider further having a fuel inlet for supplying fuel to said pumping chamber and a fuel outlet for discharging fuel from said pumping chamber, said slider being responsive to an increase in fuel pressure in said stator chamber to move from a pumping position wherein the axis of said pumping chamber is eccentric the axis of said rotor toward a neutral position wherein the axis of said pumping chamber is coincident the axis of said rotor, means biasing said slider toward said pumping position, a plurality of vanes extending radially from said rotor into engagement with said slider, an accumulator and pressure regulator having an accumulator chamber connected to said slider fuel outlet for receiving fuel from said pumping chamber, said accumulator chamber having an open end, a closed end, a fuel delivery outlet for delivering fuel to said nozzle and a pressure relief outlet extending to said stator chamber at one end of said slider, a rolling diaphragm closing said open end of said accumulator chamber and movable away from said closed end upon an increase in fuel pressure within said accumulator chamber, means biasing said diaphragm toward said closed end of said accumulator chamber, a bracket secured to said diaphragm in said accumulator chamber and engageable with said closeD end of said chamber for limiting movement of said diaphragm theretoward, a valve member disposed in said accumulator chamber and engageable with said pressure relief outlet for controlling flow from said accumulator chamber to said stator chamber, means biasing said valve member away from said diaphragm toward engagement with said pressure relief outlet, said valve member including means engageable with said bracket after said diaphragm and said bracket move a selected distance away from said closed end of said accumulator chamber to thereby disengage said valve member from said pressure relief outlet, whereby rotation of said rotor within said pumping chamber when said slider is in said pumping position may effect delivery of fuel from said slider fuel inlet, through said pumping chamber, said slider fuel outlet, said accumulator chamber, and said fuel delivery outlet to said nozzle, whereby initial displacement of said diaphragm less than said selected distance in response to an increase in fuel pressure within said accumulator chamber increases the amount of fuel accumulated in said accumulator chamber, whereby additional displacement of said diaphragm greater than said selected distance in response to an increase in fuel pressure within said chamber effects disengagement of said valve member from said pressure relief outlet and fuel is discharged from said accumulator chamber through said pressure relief outlet to said stator chamber to displace said slider toward said neutral position and thereby reduce fuel delivery from said pumping chamber, and whereby return of said diaphragm toward said closed end of said chamber upon a decrease in fuel pressure within said accumulator chamber discharges the increased amount of fuel accumulated within said accumulator chamber through said fuel delivery outlet for delivery to said nozzle.

Claim 6

In a fuel injection system, a pump for delivering fuel to an injection nozzle comprising a stator defining a stator chamber, a cylindrical rotor disposed within said stator chamber, a slider reciprocably disposed within said stator chamber and having a cylindrical pumping chamber receiving said rotor, said slider further having a fuel inlet for supplying fuel to said pumping chamber and a fuel outlet for discharging fuel from said pumping chamber, said slider being responsive to an increase in fuel pressure in said stator chamber to move from a pumping position wherein the axis of said pumping chamber is eccentric the axis of said rotor toward a neutral position wherein the axis of said pumping chamber is coincident the axis of said rotor, means biasing said slider toward said pumping position, a plurality of vanes extending radially from said rotor into engagement with said slider, an accumulator and pressure regulator having an accumulator chamber connected to said slider fuel outlet for receiving fuel from said pumping chamber, said accumulator chamber having an open end, a closed end, a fuel delivery outlet for delivering fuel to said nozzle and a pressure relief outlet extending to said stator chamber at one end of said slider, a rolling diaphragm closing said open end of said accumulator chamber and movable away from said closed end upon an increase in fuel pressure within said accumulator chamber, means biasing said diaphragm toward said closed end of said accumulator chamber, a bracket secured to said diaphragm in said accumulator chamber and engageable with said closeD end of said chamber for limiting movement of said diaphragm theretoward, a valve member disposed in said accumulator chamber and engageable with said pressure relief outlet for controlling flow from said accumulator chamber to said stator chamber, means biasing said valve member away from said diaphragm toward engagement with said pressure relief outlet, said valve member including means engageable with said bracket after said diaphragm and said bracket move a selected distance away from said closed end of said accumulator chamber to thereby disengage said valve member from said pressure relief outlet, whereby rotation of said rotor within said pumping chamber when said slider is in said pumping position may effect delivery of fuel from said slider fuel inlet, through said pumping chamber, said slider fuel outlet, said accumulator chamber, and said fuel delivery outlet to said nozzle, whereby initial displacement of said diaphragm less than said selected distance in response to an increase in fuel pressure within said accumulator chamber increases the amount of fuel accumulated in said accumulator chamber, whereby additional displacement of said diaphragm greater than said selected distance in response to an increase in fuel pressure within said chamber effects disengagement of said valve member from said pressure relief outlet and fuel is discharged from said accumulator chamber through said pressure relief outlet to said stator chamber to displace said slider toward said neutral position and thereby reduce fuel delivery from said pumping chamber, and whereby return of said diaphragm toward said closed end of said chamber upon a decrease in fuel pressure within said accumulator chamber discharges the increased amount of fuel accumulated within said accumulator chamber through said fuel delivery outlet for delivery to said nozzle.

Claim 7

The pump of claim 4 wherein said one end of said slider has an opening from said stator chamber to said slider fuel inlet to permit reduction of pressure in said stator chamber and thereby facilitate return of said slider to said pumping position under the bias of said slider biasing means.

Claim 8

The pump of claim 4 wherein said stator includes a pressure relief passage extending from said slider fuel outlet to said stator chamber at the opposite end of said slider, and which further comprises a pressure responsive valve in said passage which permits fuel flow therethrough only when the pressure in said fuel outlet exceeds a selected value, whereby excess pressure in said fuel outlet may be relieved.

Claim 9

The pump of claim 6 wherein said opposite end of said slider has an opening from said stator chamber to said slider fuel inlet to allow fuel discharged past said pressure responsive valve to flow freely to said fuel inlet.