US5121730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of conditioning fluid in an electronically-controlled unit injector for starting
Assignee: Caterpillar Inc
•
Filing: 1991-10-11
•
Granted: 1992-06-16
•
Expires: 2011-10-11
Abstract
Abstract Herein are disclosed methods of conditioning fluid, such as damping fluid, in an electronically-controlled unit injector in order to facilitate quick starting of an engine. Fluid normally used to dampen the motion of an electrical actuator assembly of the unit injector can remain in the actuator assembly after the engine is stopped. If too much fluid remains and cools off in the actuator assembly, quick starting of a cold engine may be hindered. Each of the above methods expels and/or heats up at least a portion of the remaining fluid in the actuator assembly while the engine is at rest and thereby enables quicker response of the actuator assembly when the engine is started. Such quicker response improves the fuel injection delivery capability and timing accuracy of the unit injector during engine startup.
Inventors
- 👤 Thomas G. Ausman
- 👤 John G. Ertel
- 👤 Michael A. Flinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:37
CPC Classifications
F; F02; F02M; F02M59/00; F02M59/44; F02M59/48; F02M57/00; F02M57/02; F02M57/022; F02M57/025; F02M59/02; F02M59/10; F02M59/105; F02M59/46; F02M59/466; F02B; F02B75/00; F02B75/16; F02B75/18; F02B2075/1804; F02B2075/1832; F02B2275/00; F02B2275/14; F02F; F02F7/00; F02F7/006; F02M2200/00; F02M2200/30; F02M2200/304; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
83 words
A method of conditioning damping fluid in a fuel system having an electronically-controlled unit injector and a pump operable to supply damping fluid to an electrical actuator assembly of the unit injector comprising the steps of: applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly over a selected time span prior to operating the pump; and operating the pump while applying another electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly.
Claim 2
Independent Claim
83 words
A method of conditioning damping fluid in a fuel system having an electronically-controlled unit injector and a pump operable to supply damping fluid to an electrical actuator assembly of the unit injector comprising the steps of: applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly over a selected time span prior to operating the pump; and operating the pump while applying another electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly.
Claim 3
Independent Claim
83 words
A method of conditioning actuating fluid in a fuel system having a hydraulically-actuated electronically-controlled unit injector and a pump operable to supply actuating fluid to the unit injector comprising the steps of: applying an electrical signal of a selected amplitude, pulsewidth and period to an electrical actuator assembly of the unit injector over a selected time span prior to operating the pump; and operating the pump while applying another electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly.
Claim 4
Independent Claim
83 words
A method of conditioning actuating fluid in a fuel system having a hydraulically-actuated electronically-controlled unit injector and a pump operable to supply actuating fluid to the unit injector comprising the steps of: applying an electrical signal of a selected amplitude, pulsewidth and period to an electrical actuator assembly of the unit injector over a selected time span prior to operating the pump; and operating the pump while applying another electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly.
Claim 5
Dependent Claim
73 words
The method of claim 2 further including the steps of: detecting the viscosity of actuating fluid used to actuate the unit injector and generating a viscosity indicative signal; and implementing the step, of applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly of the unit injector over a selected time span prior to operating the pump, only when the detected viscosity is above a selected value.
Claim 6
Dependent Claim
73 words
The method of claim 2 further including the steps of: detecting the temperature of actuating fluid used to actuate the unit injector and generating a temperature indicative signal; and implementing the step, of applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly of the unit injector over a selected time span prior to operating the pump, only when the detected temperature is below a selected value.
Claim 7
Independent Claim
69 words
A method of conditioning actuating fluid in a fuel system having an electronically-controlled unit injector and a pump operable to supply damping fluid to an electrical actuator assembly of the unit injector comprising the steps of: stopping the operation of the pump; and applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly over a selected time span after the pump has stopped.
Claim 8
Independent Claim
69 words
A method of conditioning actuating fluid in a fuel system having an electronically-controlled unit injector and a pump operable to supply damping fluid to an electrical actuator assembly of the unit injector comprising the steps of: stopping the operation of the pump; and applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly over a selected time span after the pump has stopped.
Claim 9
Independent Claim
69 words
A method of conditioning actuating fluid in a fuel system having a hydraulically-actuated electronically-controlled unit injector and a pump operable to supply actuating fluid to the unit injector comprising the steps of: stopping the operation of the pump; and applying an electrical signal of a selected amplitude, pulsewidth and period to an electrical actuator assembly of the unit injector over a selected time span after the pump has stopped.
Claim 10
Independent Claim
69 words
A method of conditioning actuating fluid in a fuel system having a hydraulically-actuated electronically-controlled unit injector and a pump operable to supply actuating fluid to the unit injector comprising the steps of: stopping the operation of the pump; and applying an electrical signal of a selected amplitude, pulsewidth and period to an electrical actuator assembly of the unit injector over a selected time span after the pump has stopped.
Claim 11
Dependent Claim
67 words
The method of claim 6 further including the steps of: detecting the temperature of ambient air and generating a temperature indicative signal; and implementing the step, of applying an electrical signal of a selected amplitude, pulsewidth and period to the electrical actuator assembly of the unit injector over a selected time span after the pump has stopped, only when the detected temperature is below a selected value.
References Cited (Backward Citations)
US3408007A
Cited
US3689205A
Cited
US3999525A
Cited
US3731876A
Cited
US3753426A
Cited
US3796205A
Cited
US3868939A
Cited
US3921901A
Cited
US4271807A
Cited
US4221192A
Cited
US4449507A
Cited
US4448169A
Cited
US4459959A
Cited
US4440132A
Cited
US4372272A
Cited
GB2112458A
Cited
US4392612A
Cited
JPS59185839A
Cited
US4497298A
Cited
US4568021A
Cited
US4557685A
Cited
US4605166A
Cited
US4826080A
Cited
US4807812A
Cited
US5054458A
Cited
US4869429A
Cited
US4726389A
Cited
US4869218A
Cited
US4909440A
Cited
US5067658A
Cited
US5069189A
Cited
US5050569A
Cited
US5048488A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |