Internal-combustion engines – Charge forming device – With fuel pump
Patent
1998-06-24
2000-07-04
Miller, Carl S.
Internal-combustion engines
Charge forming device
With fuel pump
123300, F02M 3704
Patent
active
060823356
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a fuel-injection pump for injection in combustion machines, especially one-cylinder diesel engines, with a pump piston disposed axially and rotatably movably in a pump cylinder with at least one intake port for fuel, a runback slot disposed on the pump piston and in communication with a stop slot for interruption of fuel delivery, mounted on the pump piston parallel to the longitudinal axis of the piston, and with a geometric connection between the end face and the shell surface of the pump piston, wherein there is provided, in order to exert a hydrodynamic influence on control of the beginning of injection, a narrow transverse slit spaced from the leading edge and running parallel or at an angle thereto and at one end discharging into the stop slot of the pump piston.
Such fuel-injection pumps are already known from the prior art. In diesel combustion machines, especially in such with direct injection, there are usually employed one-piece or block-type insertable pumps in which, because of the compact construction, it is not possible to include any kind of electrical or electronic control signals for correcting the beginning of injection in addition to the control-travel mechanism (control linkage or control rod) and the cam-driven stroke mechanism. None of the known corrections of beginning of injection is feasible without costly mechanical injection actuators to be connected as input or feedforward components to the drive.
For optimum operating values with respect to power, fuel consumption, exhaust-gas and noise emission, the beginning of injection must be advanced at higher speeds in diesel engines. In larger diesel engines, this advance setting is achieved by electronic control or complex mechanical control elements, which are described, for example, in the Bosch pamphlet of 1989 entitled "Technical Instruction: A review of diesel injection techniques" [in German]. This advance setting and the positive effects associated therewith are obviously desirable or necessary even in smaller engines. This is particularly true for starting, especially at low outside temperatures, where retarded beginning of injection is needed for initial ignition and advanced beginning of ignition is needed for subsequent further running and runup without misfiring together with the least possible hydrocarbon emissions as the speed increases. For space and cost reasons, it is not possible in the case of one-cylinder diesel engines to resort to conventional electronic control, which is complex and expensive.
Heretofore, fuel-injection pumps that cause a shift in beginning of injection by means of a chamfer on the head of the pump piston with a circumferential radial depth of about 0.5% of the piston diameter have been used for small diesel engines. Hereby, however, no differentiation between normal operation and starting/runup is possible. A further embodiment comprises a locally limited chamfer defined by a chord and having a depth of about 1.3% of the piston diameter.
DE 3424989 C2 discloses a pump piston used in a fuel-injection pump for combustion machines, by means of the structural geometry of which a reduction of the ignition retardation and thus a reduction of the combustion-pressure peaks is supposed to be achieved in the combustion chamber of the combustion machine to be supplied. For this purpose a circumferential slot which acts over the entire range of rotation of the pump piston is made in the pump piston.
All described embodiments have the disadvantage that the shift of beginning of injection depends greatly on the running play between pump piston and pump cylinder and is not differentiated between the various speed ranges.
The object of the present invention is therefore to provide an inexpensive fuel-injection pump with which improved control of the beginning of injection can be adjusted for starting, idling and top speed by means of hydrodynamic-mechanical control.
This object is achieved according to the invention by a fuel-injection pump with the features of claim 1.
In the fuel-inj
REFERENCES:
patent: 4163634 (1979-08-01), Powers
patent: 4881506 (1989-11-01), Hoecker
patent: 5020979 (1991-06-01), Askew
patent: 5097812 (1992-03-01), Augustin
patent: 5168847 (1992-12-01), Greishaber
patent: 5205262 (1993-04-01), Anton
patent: 5219280 (1993-06-01), Yashiro
patent: 5286178 (1994-02-01), Schaef
patent: 5396871 (1995-03-01), Faupel
patent: 5592915 (1997-01-01), Ishiwata
patent: 5647326 (1997-07-01), Kato
Patent Abstracts of Japan vol. 006, No. 228 (M-171), Nov. 13, 1892.
Patent Abstract of Japan 57 129227 A (Nippon Denso KK), Aug. 11, 1982.
Kampichler Guenter
Tovar Theodor
Miller Carl S.
Motorenfabrik Hatz GmbH & Co. KG.
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