US3796206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pump-and-nozzle assembly for injecting fuel in internal combustion engines
Assignee: Robert Bosch GmbH
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Filing: 1972-05-26
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Granted: 1974-03-12
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Expires: 1992-05-26
Abstract
Abstract There is described a pump-and-nozzle assembly which forms part of a fuel injection apparatus serving an internal combustion engine and which includes a reciprocating pump piston, the angular position of which determines the injected fuel quantities during the delivery strokes. The pump piston is driven by a servo piston which is intermittently exposed to pressurized fuel delivered by a pressure source. The intermittent admission of pressurized fuel to the servo piston is controlled by a valve plunger which is exposed to pressurized fuel for periods controlled by a solenoid valve.
Inventors
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Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:10
CPC Classifications
F; F02; F02M; F02M57/00; F02M57/02; F02M57/022; F02M57/025; F02M57/026; F02M59/00; F02M59/02; F02M59/10; F02M59/105
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
378 words
A fuel injection pump-and-nozzle assembly forming part of a fuel injection apparatus serving an internal combustion engine, said assembly being of the type that has (a) a pump piston executing alternating delivery strokes and return strokes, (b) a pump work chamber bounded by said pump piston, (c) a servo piston connected to said pump piston to drive the latter, said servo piston having a diameter greater than that of said pump piston, (d) a pressure source externally of said assembly for delivering fuel under pressure to said assembly, (e) first supply conduit means extending from said pressure source to said pump work chamber, (f) a servo pressure chamber bounded by said servo piston, (g) second supply conduit means extending from said pressure source to said servo pressure chamber, (h) discharge conduit means extending from said servo pressure chamber, (i) a valve plunger controlling said second supply conduit means and said discharge conduit means, said valve plunger being adapted to assume a first switching position for admitting pressurized fuel from said pressure source to said servo pressure chamber and a second switching position for establishing communication between said servo pressure chamber and said discharge conduit means, (j) electromagnetic means for causing said valve plunger to move from one of its switching positions to the other, and (k) means for varying the angular position of said pump piston for altering the quantities of fuel injected by said assembly into said engine during the delivery strokes of said pump piston, the improvement comprising, A. a third supply conduit means extending from said pressure source to said valve plunger through which pressurized fuel is delivered by said pressure source for causing displacement of said valve plunger, B. a solenoid valve in said third supply conduit means for controlling the admission of pressurized fuel to said valve plunger, said solenoid valve constituting said electromagnetic means, C a control piston connected to said valve plunger, and being disposed in said third supply conduit means between said solenoid valve and said valve plunger, and D means for intermittently energizing said solenoid valve, said control piston being intermittently exposed to pressurized fuel delivered by the pressure source, and said valve plunger having a maximum cross sectional area several times greater than that of said control piston.
Claim 2
Dependent Claim
378 words
A fuel injection pump-and-nozzle assembly forming part of a fuel injection apparatus serving an internal combustion engine, said assembly being of the type that has (a) a pump piston executing alternating delivery strokes and return strokes, (b) a pump work chamber bounded by said pump piston, (c) a servo piston connected to said pump piston to drive the latter, said servo piston having a diameter greater than that of said pump piston, (d) a pressure source externally of said assembly for delivering fuel under pressure to said assembly, (e) first supply conduit means extending from said pressure source to said pump work chamber, (f) a servo pressure chamber bounded by said servo piston, (g) second supply conduit means extending from said pressure source to said servo pressure chamber, (h) discharge conduit means extending from said servo pressure chamber, (i) a valve plunger controlling said second supply conduit means and said discharge conduit means, said valve plunger being adapted to assume a first switching position for admitting pressurized fuel from said pressure source to said servo pressure chamber and a second switching position for establishing communication between said servo pressure chamber and said discharge conduit means, (j) electromagnetic means for causing said valve plunger to move from one of its switching positions to the other, and (k) means for varying the angular position of said pump piston for altering the quantities of fuel injected by said assembly into said engine during the delivery strokes of said pump piston, the improvement comprising, A. a third supply conduit means extending from said pressure source to said valve plunger through which pressurized fuel is delivered by said pressure source for causing displacement of said valve plunger, B. a solenoid valve in said third supply conduit means for controlling the admission of pressurized fuel to said valve plunger, said solenoid valve constituting said electromagnetic means, C a control piston connected to said valve plunger, and being disposed in said third supply conduit means between said solenoid valve and said valve plunger, and D means for intermittently energizing said solenoid valve, said control piston being intermittently exposed to pressurized fuel delivered by the pressure source, and said valve plunger having a maximum cross sectional area several times greater than that of said control piston.
Claim 3
Dependent Claim
24 words
An improvement as defined in claim 1 wherein said solenoid valve is a pressure-equalized 3/2-way valve having a sphere as its movable valve member.
Claim 4
Dependent Claim
40 words
An improvement as defined in claim 1, including means for moving said valve plunger into said second position as a function of the angular position of said pump piston simultaneously with the termination of the injection during each delivery stroke.
Claim 5
Dependent Claim
30 words
An improvement as defined in claim 1, including means for varying the pressure of fuel in said second supply conduit means as a function of at least one engine parameter.
Claim 6
Dependent Claim
15 words
An improvement as defined in claim 5, wherein said engine parameter is the engine rpm.
Claim 7
Dependent Claim
15 words
An improvement as defined in claim 5, wherein said engine parameter is the engine load.
Claim 8
Dependent Claim
40 words
An improvement as defined in claim 1, including means to establish communication through a narrow throttle gap between said pump work chamber and said pressure source in the position assumed by said pump piston upon termination of its return stroke.
Claim 9
Dependent Claim
352 words
A fuel injection pump-and-nozzle assembly forming part of a fuel injection apparatus serving an internal combustion engine, said assembly being of the type that has (a) a pump piston executing alternating delivery strokes and return strokes, (b) a pump work chamber bounded by said pump piston, (c) a servo piston connected to said pump piston to drive the latter, said servo piston having a diameter greater than that of said pump piston, (d) a pressure source externally of said assembly for delivering fuel under pressure to said assembly, (e) first supply conduit means extending from said pressure source to said pump work chamber, (f) a servo pressure chamber bounded by said servo piston, (g) second supply conduit means extending from said pressure source to said servo pressure chamber, (h) discharge conduit means extending from said servo pressure chamber, (i) a valve plunger controlling said second supply conduit means and said discharge conduit means, said valve plunger being adapted to assume a first switching position for admitting pressurized fuel from said pressure source to said servo pressure chamber and a second switching position for establishing communication between said servo pressure chamber and said discharge conduit means, (j) electromagnetic means for causing said valve plunger to move from one of its switching positions to the other, and (k) means for varying the angular position of said pump piston for altering the quantities of fuel injected by said assembly into said engine during the delivery strokes of said pump piston, the improvement comprising; A. a third supply conduit means extending from said pressure source to said valve plunger through which pressurized fuel is delivered by said pressure source for causing displacement of said valve plunger, B a solenoid valve in said third supply conduit means for controlling the admission of pressurized fuel to said valve plunger, said solenoid valve constituting said electromagnetic means, C means for intermittently energizing said solenoid valve, and D means to establish communication through a narrow throttle gap between said pump work chamber and said pressure source in the position assumed by said pump piston upon termination of its return stroke.
Claim 10
Dependent Claim
352 words
A fuel injection pump-and-nozzle assembly forming part of a fuel injection apparatus serving an internal combustion engine, said assembly being of the type that has (a) a pump piston executing alternating delivery strokes and return strokes, (b) a pump work chamber bounded by said pump piston, (c) a servo piston connected to said pump piston to drive the latter, said servo piston having a diameter greater than that of said pump piston, (d) a pressure source externally of said assembly for delivering fuel under pressure to said assembly, (e) first supply conduit means extending from said pressure source to said pump work chamber, (f) a servo pressure chamber bounded by said servo piston, (g) second supply conduit means extending from said pressure source to said servo pressure chamber, (h) discharge conduit means extending from said servo pressure chamber, (i) a valve plunger controlling said second supply conduit means and said discharge conduit means, said valve plunger being adapted to assume a first switching position for admitting pressurized fuel from said pressure source to said servo pressure chamber and a second switching position for establishing communication between said servo pressure chamber and said discharge conduit means, (j) electromagnetic means for causing said valve plunger to move from one of its switching positions to the other, and (k) means for varying the angular position of said pump piston for altering the quantities of fuel injected by said assembly into said engine during the delivery strokes of said pump piston, the improvement comprising; A. a third supply conduit means extending from said pressure source to said valve plunger through which pressurized fuel is delivered by said pressure source for causing displacement of said valve plunger, B a solenoid valve in said third supply conduit means for controlling the admission of pressurized fuel to said valve plunger, said solenoid valve constituting said electromagnetic means, C means for intermittently energizing said solenoid valve, and D means to establish communication through a narrow throttle gap between said pump work chamber and said pressure source in the position assumed by said pump piston upon termination of its return stroke.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |