US4467963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single dump single solenoid fuel injector
Assignee: Bendix Corp
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Filing: 1984-01-24
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Granted: 1984-08-28
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Expires: 2004-01-24
Abstract
Abstract A unit injector having a mechanically driven piston and a remotely situated metering piston situated in a bore. The interplunger volume defining a timing chamber and the volume below the metering piston defining a metering chamber. The injector further including a single electrically responsive valve for controlling the functions of injection timing and fuel metering and a single dump port fabricated in the walls of the bore for relieving the fuel pressure on the timing chamber which correspondingly permits the pressure of fuel in the metering chamber to be decreased.
Inventors
- 👤 Albert E. Sisson
- 👤 Edward J. Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:34
CPC Classifications
F; F02; F02M; F02M57/00; F02M57/02; F02M57/022; F02M57/023; F02M57/024; F02M59/00; F02M59/20; F02M59/32; F02M61/00; F02M61/16; F02M61/20; F02M61/205
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
312 words
A fuel injector for an internal combustion engine comprising: a body having an axially extending bore, a pumping piston and a remotely positioned metering piston positioned within said bore for axial movement therein; a timing chamber defined within said bore between the pumping piston and the metering piston and a metering chamber defined between the metering piston and the lower portion of the bore; a first fuel passage having an electronically controlled valve situated therein for receiving pressurized fuel and for transmitting the fuel to the timing chamber and for establishing, when closed, a hydraulic link between said pumping piston and said metering piston; a second fuel passage for receiving pressurized fuel and for transporting the received fuel to the metering chamber; a pressure regulator situated in said second fuel passage for regulating the fuel pressure within said metering chamber at a predetermined level between the pressure level of said received pressurized fuel and the pressure level established in said timing chamber during the interval when said valve is closed and said pumping piston is retracting, said pressure regulator including means for preventing reverse fuel flow from the metering chamber to said second fuel passage; a spring chamber situated remote from the metering chamber; nozzle means situated remote from said metering chamber and partially extending into said spring chamber for selectively releasing fuel therefrom; biasing means located within said spring chamber for biasing said nozzle means in a closed position during non-injecting modes of operation; fuel passage means for providing a means for relieving pressure within the timing chamber thereby breaking said hydraulic link as said metering piston uncovers said fuel passage means as it is moved into said metering chamber under the influence of said pumping piston and for developing a hydraulic biasing force to further bias said nozzle means toward a closed condition to terminate the injection of fuel therefrom.
Claim 2
Dependent Claim
312 words
A fuel injector for an internal combustion engine comprising: a body having an axially extending bore, a pumping piston and a remotely positioned metering piston positioned within said bore for axial movement therein; a timing chamber defined within said bore between the pumping piston and the metering piston and a metering chamber defined between the metering piston and the lower portion of the bore; a first fuel passage having an electronically controlled valve situated therein for receiving pressurized fuel and for transmitting the fuel to the timing chamber and for establishing, when closed, a hydraulic link between said pumping piston and said metering piston; a second fuel passage for receiving pressurized fuel and for transporting the received fuel to the metering chamber; a pressure regulator situated in said second fuel passage for regulating the fuel pressure within said metering chamber at a predetermined level between the pressure level of said received pressurized fuel and the pressure level established in said timing chamber during the interval when said valve is closed and said pumping piston is retracting, said pressure regulator including means for preventing reverse fuel flow from the metering chamber to said second fuel passage; a spring chamber situated remote from the metering chamber; nozzle means situated remote from said metering chamber and partially extending into said spring chamber for selectively releasing fuel therefrom; biasing means located within said spring chamber for biasing said nozzle means in a closed position during non-injecting modes of operation; fuel passage means for providing a means for relieving pressure within the timing chamber thereby breaking said hydraulic link as said metering piston uncovers said fuel passage means as it is moved into said metering chamber under the influence of said pumping piston and for developing a hydraulic biasing force to further bias said nozzle means toward a closed condition to terminate the injection of fuel therefrom.
Claim 3
Dependent Claim
91 words
The fuel injector as defined in claim 1 wherein said fuel passage means includes a third fuel passage terminating at one end at the wall of said bore proximate said timing chamber therein forming in cooperation with said bore a timing chamber dump port, said third fuel passage also communicating with said spring chamber, said fuel passage means further including a fourth passage having a restrictive orifice situated therein for establishing upstream thereto an increased pressure during the period of time that fuel in the timing chamber is being dumped therethrough.
Claim 4
Dependent Claim
28 words
The fuel injector as defined in claim 2 wherein said timing chamber dump port is exposed after said metering piston has been moved downwardly by a determinable amount.
Claim 5
Dependent Claim
22 words
The fuel injector as defined in claim 3 further including motion stopping means for limiting the upward motion of said metering piston.
Claim 6
Dependent Claim
28 words
The fuel injector as defined in claim 4 wherein said motion stopping means includes a protrusion extending from said metering piston and a shoulder fabricated on said bore.
Claim 7
Dependent Claim
101 words
The fuel injector as defined in claim 2 wherein said pumping piston means includes a pumping piston joined to a cam by a rocker arm and wherein said cam includes a dwell profile to restrain the upward motion of said pumping piston for a determinable time during the dumping of fuel from said timing chamber and after said metering piston has initially uncovered said timing chamber dumping port to allow said metering piston to be moved upwardly by the pressure of the fuel within said metering chamber, as established by said pressure regulator to close off said timing chamber dump port.
Claim 8
Dependent Claim
37 words
The system as defined in claim 1 wherein said pressure regulator establishes a pressure within said metering chamber of sufficient magnitude to force said metering piston upward to terminate fluid communication through said timing chamber dump port.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |