Internal-combustion engines – Charge forming device – With fuel pump
Reexamination Certificate
1999-10-22
2001-08-28
Moulis, Thomas N. (Department: 3747)
Internal-combustion engines
Charge forming device
With fuel pump
Reexamination Certificate
active
06279543
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a pressure regulator for controlling a pre-injection quantity of fuel in internal combustion engines, preferably Diesel engines.
For a reliable and clean mixture formation within the combustion chamber, today's internal combustion engines, Diesel engines in particular, require an injection process consisting of several individual injection actions. These injection processes are divided into pre-injection and main injection of the fuel quantity. For producing the pre-injection fuel quantity, a control unit is employed which requires a high-cost electronic control system and which shows energetic losses. Frequently, a damper is employed for producing the pre-injection fuel quantity. This damper, however, cannot be fully utilized in each step of the operation. The reason for this is that the response time of the control hydraulic is too long in the event of small injection quantities due to the design of the control elements and a small pre-injection quantity can, therefore, be produced only with the help of a significant control-technical structural design and expenditure.
Therefore, it is an object of the present invention to provide the pressure regulator of the aforementioned kind such that a pre-injection quantity of fuel can be produced in each step of the operation without the necessity of a high control-technical structural design and expenditure.
SUMMARY OF THE INVENTION
This object is solved by the inventive pressure regulator by providing the pressure regulator with a control piston which is connected in a first position with a relief valve for producing a decreased pressure on an injection valve and which, in a second, subsequent position can be separated from the relief valve for producing a higher pressure.
With the inventive pressure regulator a two stage operation is created by an initial signal by an additional switching operation by means of a simple sliding control while the duration of the control action of the control piston remains constant. For as long as the control piston is connected to the relief valve during the first motion phase, only a decreased pressure acts upon the control piston and thereby on the injection valve arranged downstream. As soon as the connection to the relief valve is separated, an increased pressure acts upon the control piston and leads to a further opening of the injection valve. Thus, the desired fuel quantity can be conveyed at a constant duration of the control action and of the exerted pressure. A precision control of the pre-injection quantity in all steps of the operation without high control-technical design and expenditure is ensured by the inventive pressure regulator. A damper can be omitted because of the pressure stage so that the injection can occur with precision and quickly. This pre-injection moreover results in a high smoothness of running of the internal combustion engine and in a decrease of the exhaust gas emissions.
REFERENCES:
patent: 5622152 (1997-04-01), Ishida
patent: 5662087 (1997-09-01), McCandless
patent: 5664545 (1997-09-01), Kato
patent: 5720261 (1998-02-01), Sturman et al.
patent: 5738075 (1998-04-01), Chen et al.
patent: 5865156 (1999-02-01), Feucht et al.
patent: 5878720 (1999-03-01), Anderson et al.
patent: 6112721 (2000-09-01), Kouketsu
Lenk Martin
Martin Steffen
Niethammer Bernd
Becker Robert W.
Hydraulik-Ring GmbH
Moulis Thomas N.
Robert W. Becker & Associates
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